561 copy The Meteoritical Society 2007 Printed in USA

Meteoritics amp Planetary Science 42 Nr 45 561ndash567 (2007)Abstract available online at httpmeteoriticsorg

The Lake Bosumtwi impact structure in GhanaA brief environmental assessment and discussion of ecotourism potential

Daniel BOAMAH1 2 and Christian KOEBERL1

1Department of Geological Sciences University of Vienna Althanstrasse 14 A-1090 Vienna Austria2Geological Survey Department PO Box M80 Accra GhanaCorresponding author E-mail christiankoeberlunivieacat

(Received 17 August 2006 revision accepted 29 January 2007)

AbstractndashLake Bosumtwi is a natural inland freshwater lake that originated from a meteorite impactThe lake is becoming a popular tourist attraction in Ghana and has the potential to be developed as anecotourism site in the future However there have been some unregulated human activities andunplanned infrastructure development and there are increased levels of pollutants in the lake waterIn order to make ecotourism at Lake Bosumtwi successful in the long term the Lake BosumtwiDevelopment Committee has been formed to ensure that local people are empowered to mobilize theirown capacities It has been realized that an important criterion required to develop ecotourism in asocially responsible economically efficient and environmentally viable way is to foster aconstructive dialogue between the local people and tourists about the needs of the indigenous people

INTRODUCTION

The Bosumtwi impact structure is exposed in 21 GyrPrecambrian metasedimentary and metavolcanic rocks in theforest zone of southern Ghana (06deg30primeN 01deg25primeW) It is awell-preserved 107 Myr complex impact crater 105 km indiameter with a pronounced rim The crater is almostcompletely filled by Lake Bosumtwi which is ~8 km indiameter and up to 78 m deep at its center Bosumtwi isassociated with one of only four known tektite strewn fields(the Ivory Coast tektites) (Koeberl et al 1997) Details on thegeology of Bosumtwi and the controversies surrounding theacceptance of the impact origin and on a recent drillingproject that was supported by the International ContinentalScientific Drilling Program (ICDP) the Ghana GeologicalSurvey Department Kwame Nkrumah University of Scienceand Technology (KNUST) and various funding organizationsin Austria Canada and the USA are given by eg Koeberland Reimold (2005) and references therein (also Koeberlet al 2007)

The local people mostly farm and fish but recentlytourism has evolved as an alternative source of incomeproviding them with new employment opportunities newinfrastructure development and government revenueHowever unorganized and unplanned tourism developmentwhich is characterized by overcrowding misuse of naturalresources insensitive tourist behavior mismanagement ofwaste disposal and uncontrolled infrastructure development

can have negative impacts not only on the naturalenvironment but also on the social and cultural values of thelocal communities (see eg Prakash et al 2005)

Lake Bosumtwi being the main attraction (see Prakashet al 2005) for ecotourism in the region needs to be protectedand conserved because the increase in development aroundthe lake of the past years translates into an increase ofpollution within the lake basin which could mean apremature end to ecotourism development in the LakeBosumtwi basin A major concern is that the lake is in aclosed hydrological basin (Fig 1) (Turner et al 1996a1996b) so all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the waterquality of the lake Here we briefly assess the problemsrelated to the environment and the potential of ecotourismdevelopment in the Lake Bosumtwi basin by looking at thestate of the lake and its natural environment and discuss thecurrent status of tourism development

HYDROLOGY AND BIOGEOCHEMISTRYOF LAKE BOSUMTWI

The lake currently has no outlet although it hasapparently overflowed in the recent geologic past (egTurner et al 1996a) The most important controls on the waterbalance of the lake are rainfall directly onto and waterevaporating directly from the surface of the lake (Turner et al

562 D Boamah and C Koeberl

1996a) Of lesser importance is the runoff contributed by thelakersquos surrounding watershed It is reasonable to assumewhen considering the hydrogeological conditions that littleor no groundwater enters or leaves the basin According toTurner et al (1996a 1996b) the lake level is very sensitive tosmall changes in rainfall and other climatic parameters suchas annual mean temperature and evaporation

Although the lake is homogeneous with respect to majorion composition it is stratified into an upper oxygenated layerand a lower anoxic layer and there is an abrupt change in theconcentration profiles of pH NH4

+ PO43minus NO3

minus and Mn at adepth of 16 m (Turner et al 1996b see also data of a newstudy by Hecky and co-workers as cited in Koeberl et al2007) Previous studies of the chemistry of waters within thebasin according to Turner et al (1996b and referencestherein) included chemical analyses of lake-water samplestaken in 1934 (McGregor 1937) which indicated a sodiumbicarbonate water of low salinity and high pH and chemicaldata from some of the streams running into the basin (Whyte1975) It should be noted that owing to decomposition oforganic matter in lake sediments the lake water has ldquoturnedoverrdquo in the past leading to anoxic conditions throughout thewater column and thus to mass death of the fish population(eg Rattray 1923) Studies of Lake Bosumtwi sedimentshave included chemical analyses of two lake-mud samples(McGregor 1937) that gave the following results calculatedon a water-free basis 076 and 035 wt total sulfur and 836and 382 wt organic carbon respectively These valuesindicate a high input of detrital organic matter This is also

supported by variations in carbon and nitrogen isotopiccompositions of bulk organic matter in sediments (Talbot andJohannessen 1992) that reflect climatically induced changesto the lake and the catchment flora Organic pollution maypresent a problem in lakes such as Bosumtwi (Ansa-Asareet al 1999)

ENVIRONMENTAL ASSESSMENT

The main environmental issue at Bosumtwi is pollutantsbeing added to the lake Potential sources of pollutants are 1)agricultural activities 2) domestic activities and 3)atmospheric deposition The Bosomtwe-Atwima-KwanwomaDistrict (httpbakghanadistrictsgovgh) is one of the 21districts in the Ashanti Region and in 2002 had a totalpopulation of about 146000 people (httpwwwstatoidscomyghhtml) of which about 30000 live within theBosumtwi watershed (Prakash et al 2005 httpwwwghanadistrictscomdistricts) As elsewhere a linkbetween population size and pollution is likely

Agricultural Activities

The Lake Bosumtwi basin is home to a rural communityconsisting predominantly of farmers Some of the men in thecommunity are also fishermen The people cultivate differentkinds of crops including mainly plantain cassava cocoyamand various other vegetables with cocoa being the major cashcrop

Fig 1 A projection of the shuttle radar topography data for the area around the Bosumtwi structure (north points toward the upper left)showing the crater rim the elevation of the Obuom Range to the southeast of the crater and the faint outer ring feature with the regionaldrainage pattern (creeks from the Survey of Ghana topography regional maps after Koeberl and Reimold 2005) The drainage patternemphasizes the circular drainage in the slightly depressed annular zone outside the crater rim and shows that Bosumtwi is currently ahydrologically closed basin

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 563

Use of Agrochemicals (Pesticides and Chemical Fertilizers)Chemical fertilizers are not intensively used in the lake

basin because farming is carried out in a traditional way andmost farmers cannot afford fertilizers However in recentyears the government through the Ministry of Food andAgriculture has started supplying chemical fertilizers (egCocofeed [NPK]) to increase the cocoa yield Also the use ofpesticides (eg DDT) and some growth-enhancing chemicals(eg Gamalin 20 and Cocostar) to spray crops especiallycocoa has been increased Pesticides are necessary becauseof damage to the cocoa crop by mirids (a type of suckinginsect) which together with mealybugs and the black poddisease are the three pests that most affect cocoa in Ghanaand other West African countries The use of agrochemicals istherefore expected to increase as more farmers are turning tococoa farming (eg Gerken et al 2001) That the use ofpesticides presents a problem not only for the farmers who areexposed to them (Clarke et al 1997) but also for theconsumers and the water supply has been demonstrated byeg Ntow (2001 2005) Ntow et al (2006) Otchere (2005)and Amaoah et al (2006) These authors showed that inGhana pesticide and organochlorine residues (as well as fecalcoliform contamination) are found on vegetables in soil andin the water supply constituting a serious health risk Inparticular Ntow (2005) and Otchere (2005) confirmed thepresence of organochlorines (pesticides and polychlorinatedbiphenyls [PCBs]) in water bodies in Ghana that are similar toLake Bosumtwimdashonly with smaller relative populations Thismakes the lack of similar studies at Bosumtwi even moreworrying

Livestock and the Use of Organic FertilizersThere is quite a large population of livestock in the

communities around the lake Because of their large numberstheir impact on the lake is substantial Animals such as sheepgoats and pigs reared in the community defecate along thebanks of the lake while grazing and drinking from the lakeBecause of this it is likely that a large portion of thedroppings (containing nitrogen and phosphorus) end up closeto the shore and will be washed into the lake by the rain Somepeople have started using some of the droppings as fertilizers

Land Use (Farming) and FishingMore people of the communities around Bosumtwi rely

on agriculture than on fishing (Prakash et al 2005)Agricultural production in the lake basin is done with simplefarm tools such as the cutlass and hoes There is therefore anincrease in the utilization of unsustainable natural resourcesin terms of land cultivation overgrazing and forestexploitation One consequence of this is increased soilerosion which results in more nutrient runoff and leachingBesides that clearing and slash-and-burn practices have adirect influence on the atmospheric deposition of nutrientsWhen it rains surface runoff water washes away the soilnutrients and all the streams in the farmlands flow directly

into the lake causing enrichment of the lake water(eutrophication) The pollutants also end up in the lakethrough leaching into the groundwater The groundwater is inconnection with the lake water and seeps through the soil intothe lake The communities around the lake depend heavily onfishing as indicated by the abundance of fishing nets that areset all over the lake However there are two problemsassociated with the fishing activities that have so far not beenaddressed First the increasing population around the lake isleading to more and more fish being taken from the lakepotentially resulting in overfishing Already there areindications that mainly smallish fish can still be garneredSecond the increasing use of pesticides in farming as well asthe input of anthropogenic pollutants as mentioned aboveduring the past decades most likely has already resulted in thefish being contaminated with various chemicalsmdashbut so farno studies have been made to assess the contamination statusof the fish in Lake Bosumtwi Due to the population increasearound Lake Bosumtwi it has become clear that fishing andfarming activities cannot be sustained indefinitely

Domestic Activities

Domestic pollution loads are directly related to thepopulation size About 30000 people currently live within thelake basin or its immediate environs

Use of Detergents and Soaps in the LakeClothes are washed with detergents in the lake water and

also at the bank of the lake shore where the used water iseventually thrown into the lake Cars are also washed withdetergents along the bank of the lake shore Some of thepeople in the community bath with soaps in the lake water andfishermen wash their nets with soap in the lake

Burning of Organic and Inorganic Waste along the Lake ShoreRegularly the lake banks are weeded and the weeds are

collected and burnt also plastic found at the banks iscollected and burnt This is supposed to be part of thecommunity-sponsored environmental program to clean thelake shore But burning of PVC (polyvinyl-chloride) theworldrsquos second-most common plastic releases highlypoisonous dioxins into the atmosphere The ash is left on thebank and eventually carried into the lake by wind andrainwater

Increasing Human Activity Close to the LakeHuman activity close to the lake is increasing with

several accommodation facilities including hotels springingup next to the lake The inorganic waste and wastewatermanagement from such facilities has not yet received muchattention from the local authorities Because there is noEnvironmental Impact Assessment (EIA) plan for how to dealwith the waste all the waste originating from theseaccommodation facilities will end up in the lake

564 D Boamah and C Koeberl

Disposal of GarbageThere is indiscriminate littering at the bank of the lake

with plastic materials from food vendors and sellers of otherproducts Some of these eventually find their way into thelake Generally speaking there is uncontrolled disposal ofsolid waste as there is no serious waste management systemin place In some cases refuse washes into the lake duringrainy periods (Prakash et al 2005)

Atmospheric Deposition

Land clearing and slash-and-burn practices in theagricultural sector substantially add to emissions into theatmosphere Aside from this the nearby urban area ofKumasi may add to atmospheric deposition throughextensive burning of biomass car exhaust emissions andother forms of air pollution Because the main source ofwater into the lake is rainfall pollutants in the atmospherereturn to the lake The main source of energy (for cooking)of the people of the communities living around the lake isfuel wood

It should be noted that until the 2004 ICDP drillingproject at Lake Bosumtwi no detailed pollution study (lakelevel development with time or inout pathways) had everbeen done Such a study is a precondition for assigningecotourism value to Bosumtwi A hydrologicallimnologicalstudy by R Hecky and collaborators of the water columnbefore during and after the ICDP drilling project was doneand indicated no influence of the drilling operations on waterquality data from this study (still in progress see alsoKoeberl et al 2007) will provide important baselineinformation for a detailed pollution study

Lake Bosumtwi is situated in the famous Ashanti goldbelt of Ghana (Kesse 1985) where many private companiesare carrying out exploration However a 10 km wide bufferzone around the lake within which mineral exploration andmining activity are prohibited has been established by theGeological Survey Department and the Ministry of Minessince the beginning of 2006 to prevent further pollution byany future mining operations

ECOTOURISM POTENTIAL

Lake Bosumtwi is becoming a popular tourist attractionin Ghana and has the potential to be developed as anecotourism site Following Prakash et al (2005) theattractions related to tourism at the lake include

bull the lake itself for recreation and aesthetic valuesbull suevite outside the crater rim and its importance for

impact-cratering studiesbull rich geological and biodiversity informationbull rural landscapes lifestyles and cultural heritage of the

people (eg Lake Bosumtwi is a sacred lake of theAshanti people of Ghana see Rattray [1923])

There are also plans to build a crater museum at the crater rimto boost tourism in the area Unfortunately the plans to buildthe museum have not measurably progressed during the pastyears even though funding assistance with the design of thescientific exhibits and with exhibits themselves was pledgedby the ICDP drilling project

The tourism industry could be an alternative livelihoodfor the communities around Lake Bosumtwi that currentlydepend heavily on farming and fishing To the communitiesand local authorities of the Lake Bosumtwi basindevelopment of tourism could be important for employmentgeneration as a contribution to government revenue for theimprovement of infrastructure and for individual andcorporate income generation

ECOTOURISM DEVELOPMENT PLANS

Ecotourism is a subset of sustainable tourism differingby its focus on ecology As defined by The EcotourismSociety (wwwecotourismorg) ecotourism is ldquoresponsibletravel to natural areas that conserves the environment andimproves the well-being of local peoplerdquo it is aboutconnecting conservation communities and sustainabletravel This involves observing the following principlesminimize impact build environmental and cultural awarenessand respect provide positive experiences for both visitors andhosts provide direct financial benefits for conservation andbenefits and empowerment for local people and raisesensitivity to host countriesrsquo political environmental andsocial climate

In order to make ecotourism successful in the long termat Lake Bosumtwi a Lake Bosumtwi DevelopmentCommittee was formed by the Ashanti RegionalCoordinating Council (ARCC) in 2000 with the backing ofthe Ashanti king and the Ghana government This committeeaims to ensure that local people are empowered to make useof their own abilities Ecotourism can be developed accordingto socially responsible economically efficient andenvironmentally viable guidelines to foster a constructivedialogue about indigenous needs in terms that areunderstandable to the locals (eg Prakash et al 2005Wiggins et al 2004) For this reason there has been anincreasing interest in planning and designing ecotourismprojects and controlling how they evolve in the area

DISCUSSION

Among the well-preserved impact structures on EarthBosumtwi is outstanding because of the wealth of dataaccumulated (eg Koeberl and Reimold 2005) during the last10 years or so of intense research work that culminated in theICDP drilling project (eg Koeberl et al 2007) Bosumtwi isalso the only significant natural lake in Ghana and isrelatively easily accessible The infrastructure available in

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 565

nearby Kumasi (in terms of air and road access and hotels) aswell as accommodation facilities available at or near the lakehave led within the past few years to an increase in local(Ghanaian) tourism in the Bosumtwi area If a crater museumsimilar to those at Meteor Crater Ries or Tswaing could bebuilt at or near the crater and if it were properly advertisednot only in national but also in international sources it isconceivable that such a museum would provide an additionalattraction for the Bosumtwi region leading to an increase indedicated ldquocrater tourismrdquo

There are also plans to make Bosumtwi a UNESCOWorld Heritage Site because it is probably the best-preservedyoung complex meteorite impact crater on Earth and itsunique and attractive location in a partly original forest regionmakes it a prime geological site in Ghana In addition the lakeis a sacred place for the traditional communities of theAshanti region in Ghana The Ashanti consider LakeBosumtwi to be a god There are several sacred sites aroundthe lake that are of cultural importance to the people in theAshanti region (see eg Rattray 1923) that could serve astourist attractions (see also httppeoplefreenetdebosomtwebackgroundinfohtml)

As mentioned above the fishing and farming activitiesaround Lake Bosumtwi cannot be sustained indefinitelyThus tourism in the area is being looked at as an alternativemeans of income for the people The problem now is how toaddress the environmental issues especially with regards tothe pollution of the lake At the moment there is no agencythat acts as a watch-dog for the lake The Unit Committees(officially representing the District Assembly in thecommunity their major tasks are development sanitationand by-laws) could be important players in this regard whocould ensure that the environmental laws are followed bycommunity members Well-maintained waste bins at vantagepoints around the lake basin would also be helpful Currentlysome refuse dumps around the lake are overflowing andwaste is washed into the lake during rainfall (Prakash et al2005 p 27) Also helpful would be to educate local peopleabout the negative effects of bathing washing and cleaningin the lake with soap and detergent but of course alternativemeans (eg public showers that are connected to a properwaste-water system) would have to be provided In factusing soap in the lake is already prohibited but very few ifany fines have ever been issued (Prakash et al 2005 p 25)Furthermore education on the use of livestock droppings asorganic manure for farming should be intensified In thiscase the amount of manure that will eventually be washedinto the lake as runoff would be minimized Whereverpossible nutrient-capturing vegetation should be plantedalong the lake shore to act as a natural barrier againstnutrient influx into the lake As noted above a first step inhelping to protect and preserve Lake Bosumtwi was theestablishment (in early 2006) of a 10 km wide buffer zonearound the lake within which mineral exploration and

mining activity is prohibited Ecotourism development in theLake Bosumtwi basin undoubtedly depends to a large extenton the lake Pollution of the lake water will hinderecotourism development For one thing it will affect theaesthetic beauty of the lake owing to water contaminationand dead aquatic life This would reduce the recreational andtourism value of the lake For instance swimming in the lakewould become unpleasant or dangerous Moreover pollutedwaters could provide a habitat for waterborne and insect-borne diseases such as diarrhea bilharzia typhoid choleraand dysentery

Ecotourism aims at actively involving local people inplanning and management of the facility Both of thesestages also need involvement and efforts from localauthorities Through proper planning efficientimplementation of development and continuousmanagement of tourism the benefits of tourism to localcommunities can be optimized and the problems minimizedThe advantage is that it provides an impetus to expandtourism development and conservation of the naturalresource (Wiggins et al 2004) The prime areas for nature-based tourism including ecotourism are evidently those thatare legally protected as this offers the best guarantee formaintaining their attractions in the long term (Boo 1992Ceballos-Lascurain 1991 Wight 1993) The BosumtwiForest Reserve which is near the Ankaase community atLake Bosumtwi (Fig 2) and has an area of 140 km2 is alegally protected area that consists of semideciduoustropical rainforest and provides a typical naturalenvironment of the sort that attracts ecotourists (for detailssee Prakash et al 2005 pp 38ndash39) Environmentaleducation is one of the most obvious benefits toconservation generated by ecotourism (Boo 1992 Ceballos-Lascurain 1991 Whelan 1991) The potential of theindustry to educate tourists in order to later involve them inactive conservation efforts is well documented by eg Boo(1992) Ceballos-Lascurain (1991) and Whelan (1991)

Construction of a crater museum on the crater rim withroutes for hiking around the lake to observe impact rocks(suevites) and other aspects of the local geology also haspotential for ecotourism Planning for such a museum has totake into account the success of museums at other impactcraters such as Meteor Crater (USA) Tswaing (SouthAfrica) or Ries (Germany) The ICDP drilling project haspromised to provide expertise for the development of a cratermuseum and its exhibits The scientific contents of themuseum will include some general information on theformation of impact craters as well as on local and regionaleffects of medium-sized impact events on the geology of theBosumtwi crater in particular and information on thehydrologic and biologic aspects of Bosumtwi Thus it will beof use for the education of Ghanaian and foreign researchersand students (including school children) as well as for thepublic in general If properly advertised if the building and its

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

562 D Boamah and C Koeberl

1996a) Of lesser importance is the runoff contributed by thelakersquos surrounding watershed It is reasonable to assumewhen considering the hydrogeological conditions that littleor no groundwater enters or leaves the basin According toTurner et al (1996a 1996b) the lake level is very sensitive tosmall changes in rainfall and other climatic parameters suchas annual mean temperature and evaporation

Although the lake is homogeneous with respect to majorion composition it is stratified into an upper oxygenated layerand a lower anoxic layer and there is an abrupt change in theconcentration profiles of pH NH4

+ PO43minus NO3

minus and Mn at adepth of 16 m (Turner et al 1996b see also data of a newstudy by Hecky and co-workers as cited in Koeberl et al2007) Previous studies of the chemistry of waters within thebasin according to Turner et al (1996b and referencestherein) included chemical analyses of lake-water samplestaken in 1934 (McGregor 1937) which indicated a sodiumbicarbonate water of low salinity and high pH and chemicaldata from some of the streams running into the basin (Whyte1975) It should be noted that owing to decomposition oforganic matter in lake sediments the lake water has ldquoturnedoverrdquo in the past leading to anoxic conditions throughout thewater column and thus to mass death of the fish population(eg Rattray 1923) Studies of Lake Bosumtwi sedimentshave included chemical analyses of two lake-mud samples(McGregor 1937) that gave the following results calculatedon a water-free basis 076 and 035 wt total sulfur and 836and 382 wt organic carbon respectively These valuesindicate a high input of detrital organic matter This is also

supported by variations in carbon and nitrogen isotopiccompositions of bulk organic matter in sediments (Talbot andJohannessen 1992) that reflect climatically induced changesto the lake and the catchment flora Organic pollution maypresent a problem in lakes such as Bosumtwi (Ansa-Asareet al 1999)

ENVIRONMENTAL ASSESSMENT

The main environmental issue at Bosumtwi is pollutantsbeing added to the lake Potential sources of pollutants are 1)agricultural activities 2) domestic activities and 3)atmospheric deposition The Bosomtwe-Atwima-KwanwomaDistrict (httpbakghanadistrictsgovgh) is one of the 21districts in the Ashanti Region and in 2002 had a totalpopulation of about 146000 people (httpwwwstatoidscomyghhtml) of which about 30000 live within theBosumtwi watershed (Prakash et al 2005 httpwwwghanadistrictscomdistricts) As elsewhere a linkbetween population size and pollution is likely

Agricultural Activities

The Lake Bosumtwi basin is home to a rural communityconsisting predominantly of farmers Some of the men in thecommunity are also fishermen The people cultivate differentkinds of crops including mainly plantain cassava cocoyamand various other vegetables with cocoa being the major cashcrop

Fig 1 A projection of the shuttle radar topography data for the area around the Bosumtwi structure (north points toward the upper left)showing the crater rim the elevation of the Obuom Range to the southeast of the crater and the faint outer ring feature with the regionaldrainage pattern (creeks from the Survey of Ghana topography regional maps after Koeberl and Reimold 2005) The drainage patternemphasizes the circular drainage in the slightly depressed annular zone outside the crater rim and shows that Bosumtwi is currently ahydrologically closed basin

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 563

Use of Agrochemicals (Pesticides and Chemical Fertilizers)Chemical fertilizers are not intensively used in the lake

basin because farming is carried out in a traditional way andmost farmers cannot afford fertilizers However in recentyears the government through the Ministry of Food andAgriculture has started supplying chemical fertilizers (egCocofeed [NPK]) to increase the cocoa yield Also the use ofpesticides (eg DDT) and some growth-enhancing chemicals(eg Gamalin 20 and Cocostar) to spray crops especiallycocoa has been increased Pesticides are necessary becauseof damage to the cocoa crop by mirids (a type of suckinginsect) which together with mealybugs and the black poddisease are the three pests that most affect cocoa in Ghanaand other West African countries The use of agrochemicals istherefore expected to increase as more farmers are turning tococoa farming (eg Gerken et al 2001) That the use ofpesticides presents a problem not only for the farmers who areexposed to them (Clarke et al 1997) but also for theconsumers and the water supply has been demonstrated byeg Ntow (2001 2005) Ntow et al (2006) Otchere (2005)and Amaoah et al (2006) These authors showed that inGhana pesticide and organochlorine residues (as well as fecalcoliform contamination) are found on vegetables in soil andin the water supply constituting a serious health risk Inparticular Ntow (2005) and Otchere (2005) confirmed thepresence of organochlorines (pesticides and polychlorinatedbiphenyls [PCBs]) in water bodies in Ghana that are similar toLake Bosumtwimdashonly with smaller relative populations Thismakes the lack of similar studies at Bosumtwi even moreworrying

Livestock and the Use of Organic FertilizersThere is quite a large population of livestock in the

communities around the lake Because of their large numberstheir impact on the lake is substantial Animals such as sheepgoats and pigs reared in the community defecate along thebanks of the lake while grazing and drinking from the lakeBecause of this it is likely that a large portion of thedroppings (containing nitrogen and phosphorus) end up closeto the shore and will be washed into the lake by the rain Somepeople have started using some of the droppings as fertilizers

Land Use (Farming) and FishingMore people of the communities around Bosumtwi rely

on agriculture than on fishing (Prakash et al 2005)Agricultural production in the lake basin is done with simplefarm tools such as the cutlass and hoes There is therefore anincrease in the utilization of unsustainable natural resourcesin terms of land cultivation overgrazing and forestexploitation One consequence of this is increased soilerosion which results in more nutrient runoff and leachingBesides that clearing and slash-and-burn practices have adirect influence on the atmospheric deposition of nutrientsWhen it rains surface runoff water washes away the soilnutrients and all the streams in the farmlands flow directly

into the lake causing enrichment of the lake water(eutrophication) The pollutants also end up in the lakethrough leaching into the groundwater The groundwater is inconnection with the lake water and seeps through the soil intothe lake The communities around the lake depend heavily onfishing as indicated by the abundance of fishing nets that areset all over the lake However there are two problemsassociated with the fishing activities that have so far not beenaddressed First the increasing population around the lake isleading to more and more fish being taken from the lakepotentially resulting in overfishing Already there areindications that mainly smallish fish can still be garneredSecond the increasing use of pesticides in farming as well asthe input of anthropogenic pollutants as mentioned aboveduring the past decades most likely has already resulted in thefish being contaminated with various chemicalsmdashbut so farno studies have been made to assess the contamination statusof the fish in Lake Bosumtwi Due to the population increasearound Lake Bosumtwi it has become clear that fishing andfarming activities cannot be sustained indefinitely

Domestic Activities

Domestic pollution loads are directly related to thepopulation size About 30000 people currently live within thelake basin or its immediate environs

Use of Detergents and Soaps in the LakeClothes are washed with detergents in the lake water and

also at the bank of the lake shore where the used water iseventually thrown into the lake Cars are also washed withdetergents along the bank of the lake shore Some of thepeople in the community bath with soaps in the lake water andfishermen wash their nets with soap in the lake

Burning of Organic and Inorganic Waste along the Lake ShoreRegularly the lake banks are weeded and the weeds are

collected and burnt also plastic found at the banks iscollected and burnt This is supposed to be part of thecommunity-sponsored environmental program to clean thelake shore But burning of PVC (polyvinyl-chloride) theworldrsquos second-most common plastic releases highlypoisonous dioxins into the atmosphere The ash is left on thebank and eventually carried into the lake by wind andrainwater

Increasing Human Activity Close to the LakeHuman activity close to the lake is increasing with

several accommodation facilities including hotels springingup next to the lake The inorganic waste and wastewatermanagement from such facilities has not yet received muchattention from the local authorities Because there is noEnvironmental Impact Assessment (EIA) plan for how to dealwith the waste all the waste originating from theseaccommodation facilities will end up in the lake

564 D Boamah and C Koeberl

Disposal of GarbageThere is indiscriminate littering at the bank of the lake

with plastic materials from food vendors and sellers of otherproducts Some of these eventually find their way into thelake Generally speaking there is uncontrolled disposal ofsolid waste as there is no serious waste management systemin place In some cases refuse washes into the lake duringrainy periods (Prakash et al 2005)

Atmospheric Deposition

Land clearing and slash-and-burn practices in theagricultural sector substantially add to emissions into theatmosphere Aside from this the nearby urban area ofKumasi may add to atmospheric deposition throughextensive burning of biomass car exhaust emissions andother forms of air pollution Because the main source ofwater into the lake is rainfall pollutants in the atmospherereturn to the lake The main source of energy (for cooking)of the people of the communities living around the lake isfuel wood

It should be noted that until the 2004 ICDP drillingproject at Lake Bosumtwi no detailed pollution study (lakelevel development with time or inout pathways) had everbeen done Such a study is a precondition for assigningecotourism value to Bosumtwi A hydrologicallimnologicalstudy by R Hecky and collaborators of the water columnbefore during and after the ICDP drilling project was doneand indicated no influence of the drilling operations on waterquality data from this study (still in progress see alsoKoeberl et al 2007) will provide important baselineinformation for a detailed pollution study

Lake Bosumtwi is situated in the famous Ashanti goldbelt of Ghana (Kesse 1985) where many private companiesare carrying out exploration However a 10 km wide bufferzone around the lake within which mineral exploration andmining activity are prohibited has been established by theGeological Survey Department and the Ministry of Minessince the beginning of 2006 to prevent further pollution byany future mining operations

ECOTOURISM POTENTIAL

Lake Bosumtwi is becoming a popular tourist attractionin Ghana and has the potential to be developed as anecotourism site Following Prakash et al (2005) theattractions related to tourism at the lake include

bull the lake itself for recreation and aesthetic valuesbull suevite outside the crater rim and its importance for

impact-cratering studiesbull rich geological and biodiversity informationbull rural landscapes lifestyles and cultural heritage of the

people (eg Lake Bosumtwi is a sacred lake of theAshanti people of Ghana see Rattray [1923])

There are also plans to build a crater museum at the crater rimto boost tourism in the area Unfortunately the plans to buildthe museum have not measurably progressed during the pastyears even though funding assistance with the design of thescientific exhibits and with exhibits themselves was pledgedby the ICDP drilling project

The tourism industry could be an alternative livelihoodfor the communities around Lake Bosumtwi that currentlydepend heavily on farming and fishing To the communitiesand local authorities of the Lake Bosumtwi basindevelopment of tourism could be important for employmentgeneration as a contribution to government revenue for theimprovement of infrastructure and for individual andcorporate income generation

ECOTOURISM DEVELOPMENT PLANS

Ecotourism is a subset of sustainable tourism differingby its focus on ecology As defined by The EcotourismSociety (wwwecotourismorg) ecotourism is ldquoresponsibletravel to natural areas that conserves the environment andimproves the well-being of local peoplerdquo it is aboutconnecting conservation communities and sustainabletravel This involves observing the following principlesminimize impact build environmental and cultural awarenessand respect provide positive experiences for both visitors andhosts provide direct financial benefits for conservation andbenefits and empowerment for local people and raisesensitivity to host countriesrsquo political environmental andsocial climate

In order to make ecotourism successful in the long termat Lake Bosumtwi a Lake Bosumtwi DevelopmentCommittee was formed by the Ashanti RegionalCoordinating Council (ARCC) in 2000 with the backing ofthe Ashanti king and the Ghana government This committeeaims to ensure that local people are empowered to make useof their own abilities Ecotourism can be developed accordingto socially responsible economically efficient andenvironmentally viable guidelines to foster a constructivedialogue about indigenous needs in terms that areunderstandable to the locals (eg Prakash et al 2005Wiggins et al 2004) For this reason there has been anincreasing interest in planning and designing ecotourismprojects and controlling how they evolve in the area

DISCUSSION

Among the well-preserved impact structures on EarthBosumtwi is outstanding because of the wealth of dataaccumulated (eg Koeberl and Reimold 2005) during the last10 years or so of intense research work that culminated in theICDP drilling project (eg Koeberl et al 2007) Bosumtwi isalso the only significant natural lake in Ghana and isrelatively easily accessible The infrastructure available in

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 565

nearby Kumasi (in terms of air and road access and hotels) aswell as accommodation facilities available at or near the lakehave led within the past few years to an increase in local(Ghanaian) tourism in the Bosumtwi area If a crater museumsimilar to those at Meteor Crater Ries or Tswaing could bebuilt at or near the crater and if it were properly advertisednot only in national but also in international sources it isconceivable that such a museum would provide an additionalattraction for the Bosumtwi region leading to an increase indedicated ldquocrater tourismrdquo

There are also plans to make Bosumtwi a UNESCOWorld Heritage Site because it is probably the best-preservedyoung complex meteorite impact crater on Earth and itsunique and attractive location in a partly original forest regionmakes it a prime geological site in Ghana In addition the lakeis a sacred place for the traditional communities of theAshanti region in Ghana The Ashanti consider LakeBosumtwi to be a god There are several sacred sites aroundthe lake that are of cultural importance to the people in theAshanti region (see eg Rattray 1923) that could serve astourist attractions (see also httppeoplefreenetdebosomtwebackgroundinfohtml)

As mentioned above the fishing and farming activitiesaround Lake Bosumtwi cannot be sustained indefinitelyThus tourism in the area is being looked at as an alternativemeans of income for the people The problem now is how toaddress the environmental issues especially with regards tothe pollution of the lake At the moment there is no agencythat acts as a watch-dog for the lake The Unit Committees(officially representing the District Assembly in thecommunity their major tasks are development sanitationand by-laws) could be important players in this regard whocould ensure that the environmental laws are followed bycommunity members Well-maintained waste bins at vantagepoints around the lake basin would also be helpful Currentlysome refuse dumps around the lake are overflowing andwaste is washed into the lake during rainfall (Prakash et al2005 p 27) Also helpful would be to educate local peopleabout the negative effects of bathing washing and cleaningin the lake with soap and detergent but of course alternativemeans (eg public showers that are connected to a properwaste-water system) would have to be provided In factusing soap in the lake is already prohibited but very few ifany fines have ever been issued (Prakash et al 2005 p 25)Furthermore education on the use of livestock droppings asorganic manure for farming should be intensified In thiscase the amount of manure that will eventually be washedinto the lake as runoff would be minimized Whereverpossible nutrient-capturing vegetation should be plantedalong the lake shore to act as a natural barrier againstnutrient influx into the lake As noted above a first step inhelping to protect and preserve Lake Bosumtwi was theestablishment (in early 2006) of a 10 km wide buffer zonearound the lake within which mineral exploration and

mining activity is prohibited Ecotourism development in theLake Bosumtwi basin undoubtedly depends to a large extenton the lake Pollution of the lake water will hinderecotourism development For one thing it will affect theaesthetic beauty of the lake owing to water contaminationand dead aquatic life This would reduce the recreational andtourism value of the lake For instance swimming in the lakewould become unpleasant or dangerous Moreover pollutedwaters could provide a habitat for waterborne and insect-borne diseases such as diarrhea bilharzia typhoid choleraand dysentery

Ecotourism aims at actively involving local people inplanning and management of the facility Both of thesestages also need involvement and efforts from localauthorities Through proper planning efficientimplementation of development and continuousmanagement of tourism the benefits of tourism to localcommunities can be optimized and the problems minimizedThe advantage is that it provides an impetus to expandtourism development and conservation of the naturalresource (Wiggins et al 2004) The prime areas for nature-based tourism including ecotourism are evidently those thatare legally protected as this offers the best guarantee formaintaining their attractions in the long term (Boo 1992Ceballos-Lascurain 1991 Wight 1993) The BosumtwiForest Reserve which is near the Ankaase community atLake Bosumtwi (Fig 2) and has an area of 140 km2 is alegally protected area that consists of semideciduoustropical rainforest and provides a typical naturalenvironment of the sort that attracts ecotourists (for detailssee Prakash et al 2005 pp 38ndash39) Environmentaleducation is one of the most obvious benefits toconservation generated by ecotourism (Boo 1992 Ceballos-Lascurain 1991 Whelan 1991) The potential of theindustry to educate tourists in order to later involve them inactive conservation efforts is well documented by eg Boo(1992) Ceballos-Lascurain (1991) and Whelan (1991)

Construction of a crater museum on the crater rim withroutes for hiking around the lake to observe impact rocks(suevites) and other aspects of the local geology also haspotential for ecotourism Planning for such a museum has totake into account the success of museums at other impactcraters such as Meteor Crater (USA) Tswaing (SouthAfrica) or Ries (Germany) The ICDP drilling project haspromised to provide expertise for the development of a cratermuseum and its exhibits The scientific contents of themuseum will include some general information on theformation of impact craters as well as on local and regionaleffects of medium-sized impact events on the geology of theBosumtwi crater in particular and information on thehydrologic and biologic aspects of Bosumtwi Thus it will beof use for the education of Ghanaian and foreign researchersand students (including school children) as well as for thepublic in general If properly advertised if the building and its

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 563

Use of Agrochemicals (Pesticides and Chemical Fertilizers)Chemical fertilizers are not intensively used in the lake

basin because farming is carried out in a traditional way andmost farmers cannot afford fertilizers However in recentyears the government through the Ministry of Food andAgriculture has started supplying chemical fertilizers (egCocofeed [NPK]) to increase the cocoa yield Also the use ofpesticides (eg DDT) and some growth-enhancing chemicals(eg Gamalin 20 and Cocostar) to spray crops especiallycocoa has been increased Pesticides are necessary becauseof damage to the cocoa crop by mirids (a type of suckinginsect) which together with mealybugs and the black poddisease are the three pests that most affect cocoa in Ghanaand other West African countries The use of agrochemicals istherefore expected to increase as more farmers are turning tococoa farming (eg Gerken et al 2001) That the use ofpesticides presents a problem not only for the farmers who areexposed to them (Clarke et al 1997) but also for theconsumers and the water supply has been demonstrated byeg Ntow (2001 2005) Ntow et al (2006) Otchere (2005)and Amaoah et al (2006) These authors showed that inGhana pesticide and organochlorine residues (as well as fecalcoliform contamination) are found on vegetables in soil andin the water supply constituting a serious health risk Inparticular Ntow (2005) and Otchere (2005) confirmed thepresence of organochlorines (pesticides and polychlorinatedbiphenyls [PCBs]) in water bodies in Ghana that are similar toLake Bosumtwimdashonly with smaller relative populations Thismakes the lack of similar studies at Bosumtwi even moreworrying

Livestock and the Use of Organic FertilizersThere is quite a large population of livestock in the

communities around the lake Because of their large numberstheir impact on the lake is substantial Animals such as sheepgoats and pigs reared in the community defecate along thebanks of the lake while grazing and drinking from the lakeBecause of this it is likely that a large portion of thedroppings (containing nitrogen and phosphorus) end up closeto the shore and will be washed into the lake by the rain Somepeople have started using some of the droppings as fertilizers

Land Use (Farming) and FishingMore people of the communities around Bosumtwi rely

on agriculture than on fishing (Prakash et al 2005)Agricultural production in the lake basin is done with simplefarm tools such as the cutlass and hoes There is therefore anincrease in the utilization of unsustainable natural resourcesin terms of land cultivation overgrazing and forestexploitation One consequence of this is increased soilerosion which results in more nutrient runoff and leachingBesides that clearing and slash-and-burn practices have adirect influence on the atmospheric deposition of nutrientsWhen it rains surface runoff water washes away the soilnutrients and all the streams in the farmlands flow directly

into the lake causing enrichment of the lake water(eutrophication) The pollutants also end up in the lakethrough leaching into the groundwater The groundwater is inconnection with the lake water and seeps through the soil intothe lake The communities around the lake depend heavily onfishing as indicated by the abundance of fishing nets that areset all over the lake However there are two problemsassociated with the fishing activities that have so far not beenaddressed First the increasing population around the lake isleading to more and more fish being taken from the lakepotentially resulting in overfishing Already there areindications that mainly smallish fish can still be garneredSecond the increasing use of pesticides in farming as well asthe input of anthropogenic pollutants as mentioned aboveduring the past decades most likely has already resulted in thefish being contaminated with various chemicalsmdashbut so farno studies have been made to assess the contamination statusof the fish in Lake Bosumtwi Due to the population increasearound Lake Bosumtwi it has become clear that fishing andfarming activities cannot be sustained indefinitely

Domestic Activities

Domestic pollution loads are directly related to thepopulation size About 30000 people currently live within thelake basin or its immediate environs

Use of Detergents and Soaps in the LakeClothes are washed with detergents in the lake water and

also at the bank of the lake shore where the used water iseventually thrown into the lake Cars are also washed withdetergents along the bank of the lake shore Some of thepeople in the community bath with soaps in the lake water andfishermen wash their nets with soap in the lake

Burning of Organic and Inorganic Waste along the Lake ShoreRegularly the lake banks are weeded and the weeds are

collected and burnt also plastic found at the banks iscollected and burnt This is supposed to be part of thecommunity-sponsored environmental program to clean thelake shore But burning of PVC (polyvinyl-chloride) theworldrsquos second-most common plastic releases highlypoisonous dioxins into the atmosphere The ash is left on thebank and eventually carried into the lake by wind andrainwater

Increasing Human Activity Close to the LakeHuman activity close to the lake is increasing with

several accommodation facilities including hotels springingup next to the lake The inorganic waste and wastewatermanagement from such facilities has not yet received muchattention from the local authorities Because there is noEnvironmental Impact Assessment (EIA) plan for how to dealwith the waste all the waste originating from theseaccommodation facilities will end up in the lake

564 D Boamah and C Koeberl

Disposal of GarbageThere is indiscriminate littering at the bank of the lake

with plastic materials from food vendors and sellers of otherproducts Some of these eventually find their way into thelake Generally speaking there is uncontrolled disposal ofsolid waste as there is no serious waste management systemin place In some cases refuse washes into the lake duringrainy periods (Prakash et al 2005)

Atmospheric Deposition

Land clearing and slash-and-burn practices in theagricultural sector substantially add to emissions into theatmosphere Aside from this the nearby urban area ofKumasi may add to atmospheric deposition throughextensive burning of biomass car exhaust emissions andother forms of air pollution Because the main source ofwater into the lake is rainfall pollutants in the atmospherereturn to the lake The main source of energy (for cooking)of the people of the communities living around the lake isfuel wood

It should be noted that until the 2004 ICDP drillingproject at Lake Bosumtwi no detailed pollution study (lakelevel development with time or inout pathways) had everbeen done Such a study is a precondition for assigningecotourism value to Bosumtwi A hydrologicallimnologicalstudy by R Hecky and collaborators of the water columnbefore during and after the ICDP drilling project was doneand indicated no influence of the drilling operations on waterquality data from this study (still in progress see alsoKoeberl et al 2007) will provide important baselineinformation for a detailed pollution study

Lake Bosumtwi is situated in the famous Ashanti goldbelt of Ghana (Kesse 1985) where many private companiesare carrying out exploration However a 10 km wide bufferzone around the lake within which mineral exploration andmining activity are prohibited has been established by theGeological Survey Department and the Ministry of Minessince the beginning of 2006 to prevent further pollution byany future mining operations

ECOTOURISM POTENTIAL

Lake Bosumtwi is becoming a popular tourist attractionin Ghana and has the potential to be developed as anecotourism site Following Prakash et al (2005) theattractions related to tourism at the lake include

bull the lake itself for recreation and aesthetic valuesbull suevite outside the crater rim and its importance for

impact-cratering studiesbull rich geological and biodiversity informationbull rural landscapes lifestyles and cultural heritage of the

people (eg Lake Bosumtwi is a sacred lake of theAshanti people of Ghana see Rattray [1923])

There are also plans to build a crater museum at the crater rimto boost tourism in the area Unfortunately the plans to buildthe museum have not measurably progressed during the pastyears even though funding assistance with the design of thescientific exhibits and with exhibits themselves was pledgedby the ICDP drilling project

The tourism industry could be an alternative livelihoodfor the communities around Lake Bosumtwi that currentlydepend heavily on farming and fishing To the communitiesand local authorities of the Lake Bosumtwi basindevelopment of tourism could be important for employmentgeneration as a contribution to government revenue for theimprovement of infrastructure and for individual andcorporate income generation

ECOTOURISM DEVELOPMENT PLANS

Ecotourism is a subset of sustainable tourism differingby its focus on ecology As defined by The EcotourismSociety (wwwecotourismorg) ecotourism is ldquoresponsibletravel to natural areas that conserves the environment andimproves the well-being of local peoplerdquo it is aboutconnecting conservation communities and sustainabletravel This involves observing the following principlesminimize impact build environmental and cultural awarenessand respect provide positive experiences for both visitors andhosts provide direct financial benefits for conservation andbenefits and empowerment for local people and raisesensitivity to host countriesrsquo political environmental andsocial climate

In order to make ecotourism successful in the long termat Lake Bosumtwi a Lake Bosumtwi DevelopmentCommittee was formed by the Ashanti RegionalCoordinating Council (ARCC) in 2000 with the backing ofthe Ashanti king and the Ghana government This committeeaims to ensure that local people are empowered to make useof their own abilities Ecotourism can be developed accordingto socially responsible economically efficient andenvironmentally viable guidelines to foster a constructivedialogue about indigenous needs in terms that areunderstandable to the locals (eg Prakash et al 2005Wiggins et al 2004) For this reason there has been anincreasing interest in planning and designing ecotourismprojects and controlling how they evolve in the area

DISCUSSION

Among the well-preserved impact structures on EarthBosumtwi is outstanding because of the wealth of dataaccumulated (eg Koeberl and Reimold 2005) during the last10 years or so of intense research work that culminated in theICDP drilling project (eg Koeberl et al 2007) Bosumtwi isalso the only significant natural lake in Ghana and isrelatively easily accessible The infrastructure available in

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 565

nearby Kumasi (in terms of air and road access and hotels) aswell as accommodation facilities available at or near the lakehave led within the past few years to an increase in local(Ghanaian) tourism in the Bosumtwi area If a crater museumsimilar to those at Meteor Crater Ries or Tswaing could bebuilt at or near the crater and if it were properly advertisednot only in national but also in international sources it isconceivable that such a museum would provide an additionalattraction for the Bosumtwi region leading to an increase indedicated ldquocrater tourismrdquo

There are also plans to make Bosumtwi a UNESCOWorld Heritage Site because it is probably the best-preservedyoung complex meteorite impact crater on Earth and itsunique and attractive location in a partly original forest regionmakes it a prime geological site in Ghana In addition the lakeis a sacred place for the traditional communities of theAshanti region in Ghana The Ashanti consider LakeBosumtwi to be a god There are several sacred sites aroundthe lake that are of cultural importance to the people in theAshanti region (see eg Rattray 1923) that could serve astourist attractions (see also httppeoplefreenetdebosomtwebackgroundinfohtml)

As mentioned above the fishing and farming activitiesaround Lake Bosumtwi cannot be sustained indefinitelyThus tourism in the area is being looked at as an alternativemeans of income for the people The problem now is how toaddress the environmental issues especially with regards tothe pollution of the lake At the moment there is no agencythat acts as a watch-dog for the lake The Unit Committees(officially representing the District Assembly in thecommunity their major tasks are development sanitationand by-laws) could be important players in this regard whocould ensure that the environmental laws are followed bycommunity members Well-maintained waste bins at vantagepoints around the lake basin would also be helpful Currentlysome refuse dumps around the lake are overflowing andwaste is washed into the lake during rainfall (Prakash et al2005 p 27) Also helpful would be to educate local peopleabout the negative effects of bathing washing and cleaningin the lake with soap and detergent but of course alternativemeans (eg public showers that are connected to a properwaste-water system) would have to be provided In factusing soap in the lake is already prohibited but very few ifany fines have ever been issued (Prakash et al 2005 p 25)Furthermore education on the use of livestock droppings asorganic manure for farming should be intensified In thiscase the amount of manure that will eventually be washedinto the lake as runoff would be minimized Whereverpossible nutrient-capturing vegetation should be plantedalong the lake shore to act as a natural barrier againstnutrient influx into the lake As noted above a first step inhelping to protect and preserve Lake Bosumtwi was theestablishment (in early 2006) of a 10 km wide buffer zonearound the lake within which mineral exploration and

mining activity is prohibited Ecotourism development in theLake Bosumtwi basin undoubtedly depends to a large extenton the lake Pollution of the lake water will hinderecotourism development For one thing it will affect theaesthetic beauty of the lake owing to water contaminationand dead aquatic life This would reduce the recreational andtourism value of the lake For instance swimming in the lakewould become unpleasant or dangerous Moreover pollutedwaters could provide a habitat for waterborne and insect-borne diseases such as diarrhea bilharzia typhoid choleraand dysentery

Ecotourism aims at actively involving local people inplanning and management of the facility Both of thesestages also need involvement and efforts from localauthorities Through proper planning efficientimplementation of development and continuousmanagement of tourism the benefits of tourism to localcommunities can be optimized and the problems minimizedThe advantage is that it provides an impetus to expandtourism development and conservation of the naturalresource (Wiggins et al 2004) The prime areas for nature-based tourism including ecotourism are evidently those thatare legally protected as this offers the best guarantee formaintaining their attractions in the long term (Boo 1992Ceballos-Lascurain 1991 Wight 1993) The BosumtwiForest Reserve which is near the Ankaase community atLake Bosumtwi (Fig 2) and has an area of 140 km2 is alegally protected area that consists of semideciduoustropical rainforest and provides a typical naturalenvironment of the sort that attracts ecotourists (for detailssee Prakash et al 2005 pp 38ndash39) Environmentaleducation is one of the most obvious benefits toconservation generated by ecotourism (Boo 1992 Ceballos-Lascurain 1991 Whelan 1991) The potential of theindustry to educate tourists in order to later involve them inactive conservation efforts is well documented by eg Boo(1992) Ceballos-Lascurain (1991) and Whelan (1991)

Construction of a crater museum on the crater rim withroutes for hiking around the lake to observe impact rocks(suevites) and other aspects of the local geology also haspotential for ecotourism Planning for such a museum has totake into account the success of museums at other impactcraters such as Meteor Crater (USA) Tswaing (SouthAfrica) or Ries (Germany) The ICDP drilling project haspromised to provide expertise for the development of a cratermuseum and its exhibits The scientific contents of themuseum will include some general information on theformation of impact craters as well as on local and regionaleffects of medium-sized impact events on the geology of theBosumtwi crater in particular and information on thehydrologic and biologic aspects of Bosumtwi Thus it will beof use for the education of Ghanaian and foreign researchersand students (including school children) as well as for thepublic in general If properly advertised if the building and its

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

564 D Boamah and C Koeberl

Disposal of GarbageThere is indiscriminate littering at the bank of the lake

with plastic materials from food vendors and sellers of otherproducts Some of these eventually find their way into thelake Generally speaking there is uncontrolled disposal ofsolid waste as there is no serious waste management systemin place In some cases refuse washes into the lake duringrainy periods (Prakash et al 2005)

Atmospheric Deposition

Land clearing and slash-and-burn practices in theagricultural sector substantially add to emissions into theatmosphere Aside from this the nearby urban area ofKumasi may add to atmospheric deposition throughextensive burning of biomass car exhaust emissions andother forms of air pollution Because the main source ofwater into the lake is rainfall pollutants in the atmospherereturn to the lake The main source of energy (for cooking)of the people of the communities living around the lake isfuel wood

It should be noted that until the 2004 ICDP drillingproject at Lake Bosumtwi no detailed pollution study (lakelevel development with time or inout pathways) had everbeen done Such a study is a precondition for assigningecotourism value to Bosumtwi A hydrologicallimnologicalstudy by R Hecky and collaborators of the water columnbefore during and after the ICDP drilling project was doneand indicated no influence of the drilling operations on waterquality data from this study (still in progress see alsoKoeberl et al 2007) will provide important baselineinformation for a detailed pollution study

Lake Bosumtwi is situated in the famous Ashanti goldbelt of Ghana (Kesse 1985) where many private companiesare carrying out exploration However a 10 km wide bufferzone around the lake within which mineral exploration andmining activity are prohibited has been established by theGeological Survey Department and the Ministry of Minessince the beginning of 2006 to prevent further pollution byany future mining operations

ECOTOURISM POTENTIAL

Lake Bosumtwi is becoming a popular tourist attractionin Ghana and has the potential to be developed as anecotourism site Following Prakash et al (2005) theattractions related to tourism at the lake include

bull the lake itself for recreation and aesthetic valuesbull suevite outside the crater rim and its importance for

impact-cratering studiesbull rich geological and biodiversity informationbull rural landscapes lifestyles and cultural heritage of the

people (eg Lake Bosumtwi is a sacred lake of theAshanti people of Ghana see Rattray [1923])

There are also plans to build a crater museum at the crater rimto boost tourism in the area Unfortunately the plans to buildthe museum have not measurably progressed during the pastyears even though funding assistance with the design of thescientific exhibits and with exhibits themselves was pledgedby the ICDP drilling project

The tourism industry could be an alternative livelihoodfor the communities around Lake Bosumtwi that currentlydepend heavily on farming and fishing To the communitiesand local authorities of the Lake Bosumtwi basindevelopment of tourism could be important for employmentgeneration as a contribution to government revenue for theimprovement of infrastructure and for individual andcorporate income generation

ECOTOURISM DEVELOPMENT PLANS

Ecotourism is a subset of sustainable tourism differingby its focus on ecology As defined by The EcotourismSociety (wwwecotourismorg) ecotourism is ldquoresponsibletravel to natural areas that conserves the environment andimproves the well-being of local peoplerdquo it is aboutconnecting conservation communities and sustainabletravel This involves observing the following principlesminimize impact build environmental and cultural awarenessand respect provide positive experiences for both visitors andhosts provide direct financial benefits for conservation andbenefits and empowerment for local people and raisesensitivity to host countriesrsquo political environmental andsocial climate

In order to make ecotourism successful in the long termat Lake Bosumtwi a Lake Bosumtwi DevelopmentCommittee was formed by the Ashanti RegionalCoordinating Council (ARCC) in 2000 with the backing ofthe Ashanti king and the Ghana government This committeeaims to ensure that local people are empowered to make useof their own abilities Ecotourism can be developed accordingto socially responsible economically efficient andenvironmentally viable guidelines to foster a constructivedialogue about indigenous needs in terms that areunderstandable to the locals (eg Prakash et al 2005Wiggins et al 2004) For this reason there has been anincreasing interest in planning and designing ecotourismprojects and controlling how they evolve in the area

DISCUSSION

Among the well-preserved impact structures on EarthBosumtwi is outstanding because of the wealth of dataaccumulated (eg Koeberl and Reimold 2005) during the last10 years or so of intense research work that culminated in theICDP drilling project (eg Koeberl et al 2007) Bosumtwi isalso the only significant natural lake in Ghana and isrelatively easily accessible The infrastructure available in

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 565

nearby Kumasi (in terms of air and road access and hotels) aswell as accommodation facilities available at or near the lakehave led within the past few years to an increase in local(Ghanaian) tourism in the Bosumtwi area If a crater museumsimilar to those at Meteor Crater Ries or Tswaing could bebuilt at or near the crater and if it were properly advertisednot only in national but also in international sources it isconceivable that such a museum would provide an additionalattraction for the Bosumtwi region leading to an increase indedicated ldquocrater tourismrdquo

There are also plans to make Bosumtwi a UNESCOWorld Heritage Site because it is probably the best-preservedyoung complex meteorite impact crater on Earth and itsunique and attractive location in a partly original forest regionmakes it a prime geological site in Ghana In addition the lakeis a sacred place for the traditional communities of theAshanti region in Ghana The Ashanti consider LakeBosumtwi to be a god There are several sacred sites aroundthe lake that are of cultural importance to the people in theAshanti region (see eg Rattray 1923) that could serve astourist attractions (see also httppeoplefreenetdebosomtwebackgroundinfohtml)

As mentioned above the fishing and farming activitiesaround Lake Bosumtwi cannot be sustained indefinitelyThus tourism in the area is being looked at as an alternativemeans of income for the people The problem now is how toaddress the environmental issues especially with regards tothe pollution of the lake At the moment there is no agencythat acts as a watch-dog for the lake The Unit Committees(officially representing the District Assembly in thecommunity their major tasks are development sanitationand by-laws) could be important players in this regard whocould ensure that the environmental laws are followed bycommunity members Well-maintained waste bins at vantagepoints around the lake basin would also be helpful Currentlysome refuse dumps around the lake are overflowing andwaste is washed into the lake during rainfall (Prakash et al2005 p 27) Also helpful would be to educate local peopleabout the negative effects of bathing washing and cleaningin the lake with soap and detergent but of course alternativemeans (eg public showers that are connected to a properwaste-water system) would have to be provided In factusing soap in the lake is already prohibited but very few ifany fines have ever been issued (Prakash et al 2005 p 25)Furthermore education on the use of livestock droppings asorganic manure for farming should be intensified In thiscase the amount of manure that will eventually be washedinto the lake as runoff would be minimized Whereverpossible nutrient-capturing vegetation should be plantedalong the lake shore to act as a natural barrier againstnutrient influx into the lake As noted above a first step inhelping to protect and preserve Lake Bosumtwi was theestablishment (in early 2006) of a 10 km wide buffer zonearound the lake within which mineral exploration and

mining activity is prohibited Ecotourism development in theLake Bosumtwi basin undoubtedly depends to a large extenton the lake Pollution of the lake water will hinderecotourism development For one thing it will affect theaesthetic beauty of the lake owing to water contaminationand dead aquatic life This would reduce the recreational andtourism value of the lake For instance swimming in the lakewould become unpleasant or dangerous Moreover pollutedwaters could provide a habitat for waterborne and insect-borne diseases such as diarrhea bilharzia typhoid choleraand dysentery

Ecotourism aims at actively involving local people inplanning and management of the facility Both of thesestages also need involvement and efforts from localauthorities Through proper planning efficientimplementation of development and continuousmanagement of tourism the benefits of tourism to localcommunities can be optimized and the problems minimizedThe advantage is that it provides an impetus to expandtourism development and conservation of the naturalresource (Wiggins et al 2004) The prime areas for nature-based tourism including ecotourism are evidently those thatare legally protected as this offers the best guarantee formaintaining their attractions in the long term (Boo 1992Ceballos-Lascurain 1991 Wight 1993) The BosumtwiForest Reserve which is near the Ankaase community atLake Bosumtwi (Fig 2) and has an area of 140 km2 is alegally protected area that consists of semideciduoustropical rainforest and provides a typical naturalenvironment of the sort that attracts ecotourists (for detailssee Prakash et al 2005 pp 38ndash39) Environmentaleducation is one of the most obvious benefits toconservation generated by ecotourism (Boo 1992 Ceballos-Lascurain 1991 Whelan 1991) The potential of theindustry to educate tourists in order to later involve them inactive conservation efforts is well documented by eg Boo(1992) Ceballos-Lascurain (1991) and Whelan (1991)

Construction of a crater museum on the crater rim withroutes for hiking around the lake to observe impact rocks(suevites) and other aspects of the local geology also haspotential for ecotourism Planning for such a museum has totake into account the success of museums at other impactcraters such as Meteor Crater (USA) Tswaing (SouthAfrica) or Ries (Germany) The ICDP drilling project haspromised to provide expertise for the development of a cratermuseum and its exhibits The scientific contents of themuseum will include some general information on theformation of impact craters as well as on local and regionaleffects of medium-sized impact events on the geology of theBosumtwi crater in particular and information on thehydrologic and biologic aspects of Bosumtwi Thus it will beof use for the education of Ghanaian and foreign researchersand students (including school children) as well as for thepublic in general If properly advertised if the building and its

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 565

nearby Kumasi (in terms of air and road access and hotels) aswell as accommodation facilities available at or near the lakehave led within the past few years to an increase in local(Ghanaian) tourism in the Bosumtwi area If a crater museumsimilar to those at Meteor Crater Ries or Tswaing could bebuilt at or near the crater and if it were properly advertisednot only in national but also in international sources it isconceivable that such a museum would provide an additionalattraction for the Bosumtwi region leading to an increase indedicated ldquocrater tourismrdquo

There are also plans to make Bosumtwi a UNESCOWorld Heritage Site because it is probably the best-preservedyoung complex meteorite impact crater on Earth and itsunique and attractive location in a partly original forest regionmakes it a prime geological site in Ghana In addition the lakeis a sacred place for the traditional communities of theAshanti region in Ghana The Ashanti consider LakeBosumtwi to be a god There are several sacred sites aroundthe lake that are of cultural importance to the people in theAshanti region (see eg Rattray 1923) that could serve astourist attractions (see also httppeoplefreenetdebosomtwebackgroundinfohtml)

As mentioned above the fishing and farming activitiesaround Lake Bosumtwi cannot be sustained indefinitelyThus tourism in the area is being looked at as an alternativemeans of income for the people The problem now is how toaddress the environmental issues especially with regards tothe pollution of the lake At the moment there is no agencythat acts as a watch-dog for the lake The Unit Committees(officially representing the District Assembly in thecommunity their major tasks are development sanitationand by-laws) could be important players in this regard whocould ensure that the environmental laws are followed bycommunity members Well-maintained waste bins at vantagepoints around the lake basin would also be helpful Currentlysome refuse dumps around the lake are overflowing andwaste is washed into the lake during rainfall (Prakash et al2005 p 27) Also helpful would be to educate local peopleabout the negative effects of bathing washing and cleaningin the lake with soap and detergent but of course alternativemeans (eg public showers that are connected to a properwaste-water system) would have to be provided In factusing soap in the lake is already prohibited but very few ifany fines have ever been issued (Prakash et al 2005 p 25)Furthermore education on the use of livestock droppings asorganic manure for farming should be intensified In thiscase the amount of manure that will eventually be washedinto the lake as runoff would be minimized Whereverpossible nutrient-capturing vegetation should be plantedalong the lake shore to act as a natural barrier againstnutrient influx into the lake As noted above a first step inhelping to protect and preserve Lake Bosumtwi was theestablishment (in early 2006) of a 10 km wide buffer zonearound the lake within which mineral exploration and

mining activity is prohibited Ecotourism development in theLake Bosumtwi basin undoubtedly depends to a large extenton the lake Pollution of the lake water will hinderecotourism development For one thing it will affect theaesthetic beauty of the lake owing to water contaminationand dead aquatic life This would reduce the recreational andtourism value of the lake For instance swimming in the lakewould become unpleasant or dangerous Moreover pollutedwaters could provide a habitat for waterborne and insect-borne diseases such as diarrhea bilharzia typhoid choleraand dysentery

Ecotourism aims at actively involving local people inplanning and management of the facility Both of thesestages also need involvement and efforts from localauthorities Through proper planning efficientimplementation of development and continuousmanagement of tourism the benefits of tourism to localcommunities can be optimized and the problems minimizedThe advantage is that it provides an impetus to expandtourism development and conservation of the naturalresource (Wiggins et al 2004) The prime areas for nature-based tourism including ecotourism are evidently those thatare legally protected as this offers the best guarantee formaintaining their attractions in the long term (Boo 1992Ceballos-Lascurain 1991 Wight 1993) The BosumtwiForest Reserve which is near the Ankaase community atLake Bosumtwi (Fig 2) and has an area of 140 km2 is alegally protected area that consists of semideciduoustropical rainforest and provides a typical naturalenvironment of the sort that attracts ecotourists (for detailssee Prakash et al 2005 pp 38ndash39) Environmentaleducation is one of the most obvious benefits toconservation generated by ecotourism (Boo 1992 Ceballos-Lascurain 1991 Whelan 1991) The potential of theindustry to educate tourists in order to later involve them inactive conservation efforts is well documented by eg Boo(1992) Ceballos-Lascurain (1991) and Whelan (1991)

Construction of a crater museum on the crater rim withroutes for hiking around the lake to observe impact rocks(suevites) and other aspects of the local geology also haspotential for ecotourism Planning for such a museum has totake into account the success of museums at other impactcraters such as Meteor Crater (USA) Tswaing (SouthAfrica) or Ries (Germany) The ICDP drilling project haspromised to provide expertise for the development of a cratermuseum and its exhibits The scientific contents of themuseum will include some general information on theformation of impact craters as well as on local and regionaleffects of medium-sized impact events on the geology of theBosumtwi crater in particular and information on thehydrologic and biologic aspects of Bosumtwi Thus it will beof use for the education of Ghanaian and foreign researchersand students (including school children) as well as for thepublic in general If properly advertised if the building and its

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

566 D Boamah and C Koeberl

contents are well maintained and if properly educated guidesare available the museum could become a major touristattraction for Ghana

CONCLUSIONS

The Bosumtwi impact crater and the lake that fills it arenot only of scientific interest but also have the potential to beimportant for the development of ecotourism in GhanaHowever problems ranging from pollution (from humanindustrial and agricultural sources) to waste management toinfrastructure (eg roads hotels) need to be seriously andimmediately addressed The lake is in a hydrologically closedbasin thus all pollutants remain in the lake andconcentrations will increase in the future There is thereforethe need for comprehensive research on the state of the water

quality of the lake No such research has so far been done atBosumtwi but would be essential for understanding the statusof the lake Because the lake is the main attraction forecotourism in the area it needs protection and conservationas the decreasing environmental quality of the lake mayadversely affect ecotourism development

The formation of the crater by an extraterrestrial bodymakes Bosumtwi a unique meteorite crater heritage site inWest Africa While the area surely deserves this title itunfortunately has not yet received adequate promotion fromthe Ghanaian authorities Environmental education is one ofthe most obvious benefits to conservation generated byecotourism The potential of the ecotourism movement toeducate tourists and potentially involve them in activeconservation efforts is well documented Apart from the lakeitself for recreation and aesthetic values other areas that

Fig 2 A map of communities and roads in the Bosumtwi area The buffer zone within which no mining or mineral exploration is allowed isindicated with a dotted line

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66

Environmental assessment and discussion of ecotourism potential of Lake Bosumtwi 567

exhibit potential for ecotourism are the remnants of the moistsemideciduous forest around the lake and the exposures ofimpact breccias outside the crater rim (which if properlysignposted could be as interesting as similar locations aroundthe Ries crater in Germany) and a crater museummdashif it isproperly designed staffed and maintained An ultimate goalwould be to have Bosumtwi nominated and accepted as aGeopark or a World Heritage site to promote its immenseeducational and tourism potential There are so far only twoother sites in Africa where meteorite impact structures areprotected (the Tswaing Meteorite Crater Museum and theVredefort World Heritage Site both in South Africa) This isa call to the international community especially the impactscientists to assist in establishing a crater museum atBosumtwi and to help lay the foundations to protect thisunique geological feature

AcknowledgmentsndashSupported by the Austrian AcademicExchange Service (OumlAD) with an ldquoAlumnirdquo stipend to D Band by the Austrian FWF grant P17194-N10 to C K Wethank the Government of Ghana especially the GeologicalSurvey of Ghana and its then-director P Y O Amoako andespecially the local communities chiefs and the Asantehene(the Ashanti king) for support of scientific activities over thepast decade We appreciate critical and helpful manuscriptreviews by W U Reimold and R Gibson

Editorial HandlingmdashDr Wolf Uwe Reimold

REFERENCES

Amoah P Drechsel P Abaidoo R C and Ntow W J 2006Pesticide and pathogen contamination of vegetables in Ghanarsquosurban markets Archives of Environmental Contamination andToxicology 501ndash6

Ansa-Asare O D Marr I L and Cresser M S 1999 Evaluation ofcycling patterns of dissolved oxygen in a tropical lake as anindicator of biodegradable organic pollution The Science of theTotal Environment 231145ndash158

Boamah D and Koeberl C 2006 Petrographic studies of ldquofalloutrdquosuevite from outside the Bosumtwi impact structure GhanaMeteoritics amp Planetary Science 411171ndash1774

Boo E 1992 The ecotourism boom Planning for development andmanagement Wildlife and Human Needs Technical Paper 2Washington DC World Wildlife Fund pp 1ndash14

Ceballos-Lascurain H 1991 Tourism ecotourism and protectedareas The state of nature-based tourism around the world andguidelines for its development Cambridge World ConservationUnion 301 p

Clarke E E K Levy L S Spurgeon A and Calvert I A 1997 Theproblems associated with pesticide use by irrigation workers inGhana Occupational Medicine 47301ndash308

Gerken A Suglo J-V and Braun M 2001 Pesticides use andpolicies in Ghana An economic and institutional analysis ofcurrent practice and factors influencing pesticide use PesticidePolicy Project Publication Series 10 Hannover GermanyInstitute of Horticultural Economics University of Hannover127 p

Kesse G O 1985 The mineral and rock resources of GhanaRotterdam The Netherlands Balkema 610 p

Koeberl C and Reimold W U 2005 Bosumtwi impact crater Ghana(West Africa) An updated and revised geological map withexplanations Jahrbuch der Geologischen BundesanstaltWien (Yearbook of the Austrian Geological Survey) 14531ndash70 (+1 map 150000)

Koeberl C Bottomley R J Glass B P and Storzer D 1997Geochemistry and age of Ivory Coast tektites and microtektitesGeochimica et Cosmochimica Acta 611745ndash1772

Koeberl C Milkereit B Overpeck J T Scholz C A AmoakoP Y O Boamah D Danuor S Karp T Kueck J Hecky R EKing J and Peck J A 2007 An international andmultidisciplinary drilling project into a young complex impactstructure The 2004 ICDP Bosumtwi Crater Drilling ProjectmdashAnoverview Meteoritics amp Planetary Science This issue

McGregor D P 1937 Results of a hydrographic survey of LakeBosumtwi Gold Coast Geological Survey Bulletin 839ndash46

Ntow W J 2001 Organochlorine pesticides in water sedimentcrops and human fluids in a farming community in GhanaArchives of Environmental Contamination and Toxicology 40557ndash563

Ntow W J 2005 Pesticide residues in Volta Lake Ghana Lakes ampReservoirs Research and Management 10243ndash250

Ntow W J Gijzen H J Kelderman P and Drechsel P 2006 Farmerperceptions and pesticide use practices in vegetable production inGhana Pest Management Science 62356ndash365

Otchere F A 2005 Organochlorines (PCBs and pesticides) in thebivalves Anadara (Senilis) senilis Crassostrea tulipa and Pernaperna from the lagoons of Ghana The Science of the TotalEnvironment 348102ndash114

Prakash S Wieringa P Ros B Poels E Boateng F S GyampohB A and Asiseh F 2005 Potential of ecotourism developmentin the Lake Bosumtwi Basin A case study of Ankaase in theAmansie East District Ghana Working Paper 15 WorkingGroup Socio-Economics of Forest Use in the Tropics andSubtropics University of Freiburg Germany 52 p

Rattray R S 1923 Ashanti Oxford Clarendon PressOxfordUniversity Press 348 p

Talbot M R and Johannessen T 1992 A high-resolutionpaleoclimatic record for the last 27500 years in tropical WestAfrica from the carbon and nitrogen isotopic composition oflacustrine organic matter Earth and Planetary Science Letters11023ndash37

Turner B F Gardner L R and Sharp W E 1996a The hydrologyof Lake Bosumtwi a climate-sensitive lake in Ghana WestAfrica Journal of Hydrology 183243ndash261

Turner B F Gardner L R Sharp W E and Blood E R 1996b Thegeochemistry of Lake Bosumtwi a hydrologically closed basinin the humid zone of tropical Ghana Limnology andOceanography 411415ndash1424

Whelan T 1991 Ecotourism and its role in sustainable developmentIn Nature tourism Managing for the environment edited byWhelan T Washington DC Island Press pp 3ndash23

Whyte S A 1975 Distribution trophic relationships and breedinghabits of the fish populations in a tropical lake basin (LakeBosumtwi Ghana) Journal of Zoology 17725ndash56

Wiggins S Marfo K and Anchirinah V 2004 Protecting the forestor the people Environmental policies and livelihoods in theforest margins of southern Ghana World Development 321939ndash1955

Wight P A 1993 Sustainable ecotourism Balancing economicenvironmental and social goals within an ethical frameworkJournal of Tourism Studies 454ndash66