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Marine Pollution Bulletin 51 (2005) 481–485

Editorial

A common sense approach for confronting coral reef declineassociated with human activities

Welcome to this Special Issue of Marine Pollution Bul-letin, which is devoted to approaches that can help inunderstanding and managing human impacts on coralreefs.

The scientific literature over the last decade is awashwith papers describing the rapid demise of the world�scoral reef ecosystems. We are not going to add to this here,other than to re-iterate the simple and chilling consensus atwhich the coral reef research community has arrived: largenumbers of reefs across the globe, comprising some of theWorld�s most valuable, diverse and beautiful ecosystems,are in serious decline and all indications are that it is goingto get worse.

The literature also makes it quite apparent that humanactivities are playing a major role in this demise, contribut-ing to the conversion of habitats dominated by corals tothose dominated by algae, to coral bleaching, disease,mortality, erosion and reef loss.

These activities can be global, regional or local in scale.Globally, the generation of greenhouse gases is bringingabout worldwide increases in sea level, water temperatureand oceanic acidification. Regionally, coastal residential,industrial and agricultural developments have been asso-ciated with loss of filtering wetland habitats such as man-groves and increased inputs of sewage, industrial dischargesand sediments onto large tracts of reefs. More localizeddegradations are also pervasive, including overfishing of her-bivorous fish that check algal overgrowth, intensive aqua-culture operations that can drastically alter the localbalance of nutrients and tourism activities, where the handsand feet of well meaning visitors to a reef can crush and killthe very objects of their observations.

So why, despite all of this knowledge, are we not pre-venting this decline? Scientists and environmental manag-ers have provided important information alerting us tothe problem of reef demise and have continued to docu-ment the unfolding of this global catastrophe. Science hasalso provided important information about the factors thatcan contribute to reef decline. However, we are yet to takethe critical step, the step that forensically links these two

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doi:10.1016/j.marpolbul.2005.08.011

pieces of information (effects and causes) together for spe-cific reefs in given locations. In other words, rather thansaying �nutrient enrichment is a factor that can contributeto the degradation of a local reef and that such degradationmay damage the quality of life or economic well being ofthe local or regional human population� it is about saying�nutrient enrichment is at least partly responsible for thereef degradation we see in this locality and this degradationis damaging quality of life or economic well being�. To beable to do this we must begin undertaking coral reef sciencewithin clear, outcome-driven management frameworks, thesole objective of which is not simply to document declinebut to stop and reverse this unacceptable situation. Thisproblem was first highlighted six years ago by Risk(1999) and we re-iterate here that the time for identifyingthe problem of global reef decline is over and needs to beurgently replaced by an era of science and managementto mitigate this.

In this regard, what can we, the environmental scientistsand managers, do? Perhaps we could start by keeping thelanguage simple, accepting that we need to promote clear,simple ideas that are easy to understand and have meaningto local populations whose primary concerns are morelikely to be their personal quality of life than �the sustain-ability of reef ecological diversity�. From there, perhapswe could go on to identify a few basic steps for bringingabout a change in the destiny of our reefs by influencingthe one thing we can change: human behaviour. We inviteyou to explore with us a few simple steps that we believe, asscientists, environmental managers and policy makers,could help meet this objective. We ask you to think abouta reef you know or have visited and ask yourself each of thefollowing questions in the steps below.

The first step we believe should be about making clearwhy there is a need to conserve or restore the reef:

Question 1: ‘If this reef dies what will be lost in terms of

financial contribution to the local and regional economyand how would the quality of life of people in the region

be affected?’

482 Editorial / Marine Pollution Bulletin 51 (2005) 481–485

We submit to you that many (ourselves included) maystruggle with answering this. But it is crucially important:if people understand the kind of reef environment thatneeds to exist off their coasts to sustain their quality of life-values that mean something to them—there�s a chance theywill agree that effort should be put in to conserving orrestoring their area of reef and they may be more willingto change their behaviour. Without this, there will be littleincentive to bring about change.

Understanding the local reef environment, as best wecan and given the best available information, is the secondstep. Although we could spend decades trying to developand perfect our understanding of reef structure, function,resilience etc. (and there is no doubt that this is importantwork), we need to put this in context: in a few decades theremay be few reefs left on which to apply this understanding.For now, let�s focus on what we know now to answer thisquestion:

Question 2: ‘What sort of reef would I expect to see if

there was little or no human impact and what sort of reef

do I actually see?’

Is it fairly close to what we expect? Is it a large boulderstrewn landscape covered in algae, or clouded with silt? Is itsomewhere in between? Are the types and numbers of cor-als roughly what we would expect? Are some importantfunctional groups (e.g., bioeroders, grazers) absent (Bell-wood et al., 2004)? To answer this we need to know whatbroad type of reef we are examining: is it, for example, aCaribbean sheltered patch reef or a Pacific exposed fringingreef? The trained eye of a local scientist and knowledge oflocal people who have dived and fished the reef over previ-ous decades can help with providing this type of informa-tion. Local residents could also provide informationabout important events, both human and natural, thatmay have contributed to the way the reef is today; forexample the passing of memorable hurricanes. What ifthe underwater landscape is a wasteland and there are nopristine reefs any where near the locality with which tocompare? Taking a quick look into the recent geologicalpast could help tell us what was once there (Leao andKikuchi, 2005).

The third step in the process is about identifying whatactivities may be impacting the reef:

Question 3: ‘If I look around the area, are there

any human activities that could potentially impact the

reef?’

As highlighted above, human activities can result inpressures that may be global, regional or local in scale. Itwould be easy for us to surrender and say that major globalpressures on reefs such as rising water temperatures associ-ated with greenhouse gas emissions and climate change arelargely beyond our control and that there is little point inmaking a dent in the problem by dealing with regionaland local pressures.

However, we know that regional and local pressures areimportant and that if these pressures are reduced (e.g., bytreating raw sewage before discharge) reefs can and do re-cover (Grigg, 1995). By addressing local and regional pres-sures reefs might also be more able to cope with or adapt toglobal pressures that are far harder to manage. Mappinglocal and regional land use and associated practices, thelocation of point source discharges (e.g., sewage outfalls)and understanding the nature and size of local fishing acti-vities can tell us which local and regional pressures may beinfluencing a reef. By identifying associated input routesinto reefs (e.g., rivers) along with an understanding of whathappens to these rivers when they reach the coast (e.g., esti-mations of current flows and directions) we can start toaddress our fourth question:

Question 4: ‘Do I think that any of the local or regional

human activities I have identified pose a risk to this spe-

cific reef ’

The aim is to determine the likelihood that one or moreactivities (e.g., deforestation) and their associated pressures(e.g., high sediment inputs) are partially or wholly respon-sible for the observed reef decline. A significant amount ofthis risk mapping work is already being undertaken and isfreely available through the World Resources Institute,which has produced an invaluable resource in terms ofboth reports and maps to help with answering this question(http://marine.wri.org/publications.cfm).

If the economic or cultural value of a reef is extremelyhigh, then identifying that a particular human activity isassociated with significant risk of damaging that reef maybe all that is needed to promote mitigatory action. In mostcases, however, there is a need for evidence to show thatone or more of the identified pressures is causing or is likelyto cause the deterioration of a given reef and an under-standing of what sort and magnitude of change is neededto stop and reverse this. Where risks are predicted, thereneeds to be causal evidence of impact:

Question 5: ‘Of the activities I have identified as posing a

risk to the reef, is there evidence of impact associated with

these activities’

This evidence needs to firstly demonstrate the reef is notwhat we expect it should be (question 2 above) andsecondly, link this deterioration to specifically identifiedhuman activities and their pressures, at local and regionallevels, distinguishing it from natural factors. Unfortu-nately, we are simply not collecting enough or necessarilythe right kind of information to make these forensicallyacceptable causal links. The data we continue to collectfor identifying reef stress and fingerprinting its causes arestill very limited (Risk, 1999).

To forensically document impact there is of course aneed to undertake the important business of counting thenumbers and types of things living, diseased or dead onthe reef using community-based surveys, particularly if this

Editorial / Marine Pollution Bulletin 51 (2005) 481–485 483

includes critical functional groups (Bellwood et al., 2004).But this information is really only useful if it is collectedover time and if we also understand what has changed overthat time period in terms of human activity (e.g., relocationof a sewage outfall) and natural events (e.g., the passing ofa large hurricane) (Grigg, 1995). Given that reefs are natu-rally dynamic ecosystems, understanding this context is offundamental importance. Geochemical signals in coralscan prove useful in this regard, particularly when lookedat in combination with coral growth records.

In actual fact the coral reef science and managementcommunity is, in many parts of the globe, rather good atproviding community-based data on how coral reefs arechanging over time. The key thing is to understand the con-text, at local and regional scales.

It is relatively straight forward to show causality usingcommunity-based approaches alone when you are dealingwith a single point source and where everything around itis dead, while reefs further away are flourishing. Whatabout the very common problem of multiple, often diffusepressures, such as a combination of sediments, pathogens,nutrients and pesticides from catchments? Any observedreef deterioration may be integrative of the effects of manycombined pressures. We need to make measurements thatshow pressure-specific impact, linking the deteriorationwe see to the human activities we can change. This bringsus on to a critical issue: what are we going to measureand can those measurements be done in a realisticallycost-effective way?

One simple example is that of nutrient inputs from agri-cultural activity into reefs, which we know to be an impor-tant pressure. It makes sense to measure these and, forexample, relate this to the amount of algal cover and thenumbers of herbivorous grazers in reef transect observa-tions. Although undertaking dissolved nutrient analysesby spectrophotometry may appear quite straight forwardin some parts of the globe, there may still be significantlogistical and financial issues associated with doing suchanalyses in other parts. Cost-effective alternatives such ashand held and solar powered sensors or dipsticks may bebetter approaches. We need tools that are economical, veryrobust, require little training, need little or no power andconsumables and can therefore be used by all. These argu-ments are not new. We challenge you, and ourselves, toestablish a matrix of relevant pressure/impact measuresspecifically relevant to reef ecosystems and identify a setof economical tools to measure these as part of our surveys.Initiatives such as the IOC/UNESCO endorsed RAMP(Rapid Assessment of Marine Pollution) programme,which comprises a set of procedures and tools (includingrapid, simple chemical measurements, bioassays, biomark-ers and socio–economic assessment methods) may helpprovide solutions in this regard.

By this stage in our step wise process we should haveidentified some basic but essential pieces of information:we should have identified one or more human activities

and their associated pressures (e.g., agricultural activityand nutrients), their sources, inputs and whether they poserisks; we should have an idea that our reef is declining or isshowing incontrovertible signs that this will occur and weshould have evidence of impacts linking this decline in partor in total to the pressure(s).

If the cultural and economic value of the reef in ques-tion is also known, we can now identify the advantagesand disadvantages of, for example, changing land usepractices in a catchment and/or fishing practices versuslosing the reef to algal overgrowth. This can provide thesort of information environmental managers need to maketough decisions. And this brings us to our penultimatequestion:

Question 6: ‘What legislation or voluntary agreements are

available to change human activities we know pose risks to

and are impacting our reef?’

Different countries have of course different levels ofenvironmental protection legislation—the point is this: inaddition to knowing that there is a problem, what mecha-nisms, if any, are available for fixing it and who are the rel-evant people we need to work with?

And, using the information gathered above, we come tothe last question:

Question 7: ‘Can I write a one page action plan with threepriorities that, if put in place, could bring about change to

the reef?’

Irrespective of whether you have been able to answerany of the preceding questions, we ask you to try and dothis now. Think about the reef you know and try to writedown just three changes to human activities in the areaor region you believe might help restore that reef, or ifyou think it is in pretty good shape, to conserve it as itis. If you have not been able to think of one activitychange, think about how you might go about identifyingthis. If you have identified one or more thing, think aboutthe information, the evidence you would need to push thesethrough. Information you would need to share with thepublic, with industry, with farmers to convince them tomake changes. Perhaps the steps above can help.

We began to explore some of the elements of thisstepwise process at the First International Coral Reef Eco-toxicology and Health Workshop held in Bermuda in Sep-tember 2003 (www.bbsr.edu/ecotox/ecotox). A number ofthe papers within this Special Issue resulted from the dis-cussions, laboratory and field studies and presentationsthat occurred during that week. The workshop series wasestablished to provide a global forum where scientists,environmental managers, students and others could meetspecifically to discuss human impacts on reefs and theirmanagement, including emerging concepts, tools andtechniques.

The focus of the first workshop was on emerging diag-nostic tools for establishing causal links between pressures

484 Editorial / Marine Pollution Bulletin 51 (2005) 481–485

and reef decline. A key aspect of the workshop was to testthese ideas and techniques using real world situations. Wechose a very visible point source of pollutants, a municipalwaste dump receiving non combustible waste for the Is-land of Bermuda, a dump that is semi submerged in a la-goonal patch reef ecosystem known as Castle Harbour(Back Cover Picture, details in Flood et al., 2005). Someof the studies conducted and published in the Special Issueshow both that the overall number and types of corals inthis ecosystem are lower than in other reefs in Bermudaand (using emerging techniques) that organisms, includingcorals, within Castle Harbour are exhibiting stress andcommunity responses consistent with both pollutant expo-sure and chronic sedimentation when compared to coralsat a relatively pristine site many kilometers away fromthe Island itself (pictured on the front cover); (Morganet al., 2005; Quinn et al., 2005; Flood et al., 2005). Ahistorical retrospective (Flood et al., 2005) shows this isa likely consequence of major landfill activity whichhappened many decades ago and from which the reefsappear not to have fully recovered. These sorts of studiestell us that there is value in considering measures that re-duce chronic sedimentation and contamination in thisarea, which in turn could help restore the local reefecosystem.

In fact, many elements of the step-wise approach high-lighted above are already being promoted in some reefecosystems, such as the Great Barrier Reef (Hutchingset al., 2005). The Reef Water Quality Protection Plan(referenced within) was developed from a scientific assess-ment of pressures, risks and impacts, in this case identify-ing diffuse pollution from land use practices in catchmentssurrounding the barrier reef as a major issue. As part ofthis, a socio–economic appraisal was undertaken and themechanisms available (e.g., regulation, economic incen-tives) to bring about change identified. The InternationalCoral Reef Action Network (ICRAN) strategy (www.icran.org/doc/sap.doc) also incorporates some elements of thisapproach, notably through important initiatives such asthe Reefs at Risk publication and map series discussedabove and activities that establish economic valuations ofreefs.

And of course, the entire step-wise process above isnot new. It is in fact the basis of sweeping environmentallegislation emerging in Europe called the Water Frame-work Directive (http://www.environment-agency.gov.uk/wfd). Central to the Water Framework Directive is anoverarching ecological objective, the restoration of allwater bodies to good ecological status by 2015. Critically,member states in the European Union are bound withinlegislation to achieve this. The legislation has a target, amethodology based around the steps above to achieve itand a deadline within which it has to be achieved. It isalso backed up by the rule of law: this is legislation withteeth.

We strongly suggest that global conventions for pro-tecting reefs (an excellent review of which is published

by the United Nations Environment Programme, 2003)should have similar overarching ecological targets for atleast stabilising the extent of reef cover and critical reeffunctional groups across our planet. There is a pressingneed for binding legislation which obliges countries acrossthe globe with reef ecosystems to achieve such targets in agiven time frame and a common sense, simple method toachieve these. We acknowledge that the approach aboveis necessarily simplistic. We might also be accused of beingnaive to call for ecological targets for reef ecosystems, tocall for global or regional �reef framework directives�.Although there would inevitably be significant challenges,the experience in Europe suggests that these can beovercome.

Given that time may be pressing, perhaps there arethings that can be done now at local and regional levels,some steps we can take ourselves. And so, in conclusion,we return back to our quiz: how have you got on? If youhave managed to answer one or two questions we congrat-ulate you and urge you to pull together some informationto answer the others. Because, in the end we suspect theprotection and restoration of reefs will require an abilityto answer all seven questions if we are to really bring aboutchange. And if you have been able to answer all seven ques-tions, please give us a report on how your reef is makingout: we would really like to know.

Acknowledgements

We thank the Ocean Fund, Miami, US National Oce-anic Atmospheric Administration and Bermuda Govern-ment, Department of Environmental Protection forfunding the First International Coral Reef Ecotoxicologyand Health Workshop and Craig Pinney, Sandra Zielkeand Claudia Hohn for their help during the workshop.We would particularly like to thank Lady Judy Verekerand BBSR Trustee Mr. Ray Moore for their support; wegratefully dedicate this Special Issue of Marine PollutionBulletin to them.

References

Bellwood, D.R., Hughes, T.P., Folke, C., Nystrom, M., 2004. Confront-ing the coral reef crisis. Nature 429, 827–833.

Flood, V.S., Pitt, J.M., Smith, S.R., 2005. Historical and ecologicalanalysis of coral communities in Castle Harbour (Bermuda) after morethan a century of environmental perturbation. Marine PollutionBulletin.

Grigg, R.W., 1995. Coral reefs in an urban embayment in Hawaii: acomplex case history controlled by natural and anthropogenic stress.Coral Reefs 14, 253–266.

Hutchings, P., Haynes, D., Goudkamp, K., McCook, L., 2005. Catchmentto reef: water quality issues in the Great Barrier Reef Region – Anoverview of papers. Marine Pollution Bulletin 51, 3–8.

Leao, Z., Kikuchi, R., 2005. A relic coral fauna threatened by globalchanges and human activities, Eastern Brazil. Marine PollutionBulletin.

Morgan, M.B., Edge, S.E., Snell, T.W., 2005. Profiling differential geneexpression of corals along a transect of waters adjacent to the Bermudamunicipal dump. Marine Pollution Bulletin.

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Quinn, B., Gagne, F., Weber, J.-P., Blaise, C., 2005. Ecotoxicologicaleffects of a semi-submerged municipal dump (Castle Harbour,Bermuda) on the Calico scallop Argopecten gibbus. Marine PollutionBulletin.

Risk, M.J., 1999. Paradise lost: how marine science failed the world�s coralreefs. Marine and Freshwater Research 50, 831–837.

United Nations Environment Programme (2003) Conventions and CoralReefs. Available at http://www.unep.org/PDF/Conventions_Coral-Reefs_optimized.pdf.

Richard OwenBermuda Biological Station for Research

St. Georges GE01

Bermuda

UK Environment Agency

Burghill RoadBristol BS10 6BF

UK

E-mail address: richard.owen@environment-agency.gov.uk

Carys MitchelmoreCenter for Environmental Science

Chesapeake Biological Laboratory

University of Maryland

P.O. Box 38

Solomons

MD 20688

USA

Cheryl WoodleyUS National Oceanic and Atmospheric Administration

Charleston

SC 29412USA

Hank Trapido-RosenthalSchool of Ocean and Earth Science and Technology

University of Hawaii at Manoa

Honolulu

Hawaii 96822USA

Bermuda Biological Station for Research

St. Georges GE01

Bermuda

Tamara GallowayEcotoxicology and Stress Biology Research Group

School of Biological Sciences

University of Plymouth

Drake Circus

Plymouth PL4 8AAUK

Michael DepledgeUK Environment Agency

Burghill Road

Bristol BS10 6BF

UK

James ReadmanPlymouth Marine Biology Laboratory

Prospect Place

Plymouth PL1 3DH

UK

Lucy BuxtonSamia SarkisRoss Jones

Anthony KnapBermuda Biological Station for Research

St. Georges GE01

Bermuda