These activities and backgtound information were developed to be used with the Audubon FreshwterMarsh aad Saltwater Marsh Poster. The posters are available frotn your local Audubon Society orfrom

National Audubon SocietyRoute 4

Sharon, Connecticut 06069�03! 364-0520

The price for the poster wiU vary according to the number purchased.

The activities may be duplicated aad used for educational purposes, ho~ever, they axe not to beresold.

Eleanor Abratas, Marine Educational SpecialistLyle M. Soniat, Marine Educational Specialist

Kea Varden Cover DesignerBonnie Grayson, Graphics

The activities were developed as a part of the Louisiana Departmeat of Wildlife aad Fisheries~c Education Program. To obtain information oa how to receive this educationaltaaterial contact;

Paul Jackson, Aquatic Education Coordinatortuuisiana Deyaetment of Wildlife aad Fisheries

1213 North lakeshore Drive

Lake Charles, la 70601�18! 491-2585

LQUISIAI4ASEA GRANT

CcNege Program. ~44

WETLANDS � FRESH A|SD SALT

BACKGROUND INFORMATION

General Marsh Ecology

Marshes are an important interface betweenthe land and open wa ter, Life forms are com-plex and diverse because of the combination ofaquatic and terrestrial environments. For ex-ample, marshes serve as breeding, resting, andwintering grounds for many migratory birds.Often, open-wa ter organisms move temporarilyto wetlands to locate needed food. Besides beingareas of high food productivity, marshes areprime areas for spawning eggs and for juvenileyoung to feed and grow. The young of manyspecies remain in rnarshes for extended periodsof time and then migrate to other environments.Numerous species of fish are directly dependentupon marshes for food, protection, and repro-duction,

As in anyenviron-

ment, everyplant and

nirnal in the

h is part of a foodA food chain

lly depicts theof energyplants andAny food chainpla nts becausehe sun's energyd carbohydra tes,pounds such asde and water aremg the sun' se food inaphotosynthesis.pla nts breakrs and carbohy-he stored energywth, tissueand reproduc-

ls are not ca-

otosynthesis, soat either plantsthat have eaten

et the energyfor survival and

tion, All a foodows is which

g rn is eating whichplant or animaL

Organisms that consume similar food in anecosystem are assigned the same trophic level orconsumer level. So a simple food chain canconsist of several different trophic levels. Pri-mary producers, or plants, are the first trophiclevel They are able to use the radiant energyfrom the sun to combine carbon dioxide andwater to form food. Primary consumers areanimals that eat plants, Secondary consumers eatprimary consumers, and tertiary cori surners ea tthe seconda ry consumers.

The individual trophic or consumer levelsare further broken down to show the types offoods that a nirnals typical ly eat. Herbivores eatonly plants, so they can only be found in the firsttrophic level of a food chain. Carnivores ea t onlymeat, so they can be either a secondary ortertiary consumer. The kind of prey the carni-vore is eating designates its temporary consuinerlevel. For example, if a speckled trout eats a fishthat has eaten a primary consumer, the trout is asecondary consumer, However, if the speckledtrout eats a fish that has eaten a shrimp, then thetrout is a tertiary consumer. The last consumertype is the omnivore. Ornnivores eat plants andanimals and, like carnivores, their consumerlevel is determined according to the plants oranimals they recently ate. For instance, a humanis an omnivore, If a person eats vegetables, he isa primary consumer. lf he eats a steak, he is asecondary consumer. FinaBy if he eats a speck-led trout, he would probably be a tertiary con-surner.

As shown above, animals eat a variety offoods. While a food cham cannot show thedifferent kinds of prey an animal can eat, a foodweb can. A food web illustrates the relationshipsamong the consumer types by showing thevariety of food an anima! might eat in an ecosys-tem. In addition, decomposers are shown withinthe food web diagram. Decomposers are organ-isms that feed on dead plants and anunals,releasing the energy and nutrients trapped in thedead tissue. The energy is used by the decorn-posers to live, grow, and reproduce, but nutri-ents go back into the soil to be used by plants,All matter is recycled in an ecosystem.

However, energy does not recycle. Energyflows through an ecosystem, and some is lostat each trophic levek Sunlight must pour uponthe earth for life to continue. Without the sun,plants and animals would not be able to live,

grow or reproduce. PlanLs capture energy fromthe sun and that energy is transferred throughthe food web, ln all life procemsiw, such asrespiration, growth, tissue nxiintenance, andmovement, heat is given off into the atmosphere.Therefore, energy is lost at each trophic level. Ateach successively higher level of the frxxl chain,there is less of the original sun energy capturedby the plants. In fact, about IO percent ot theenergy of one level is passtxi on to the next level.

For example, a shrimp a prim.iry consumer!eats a plant and gains 100 calories of carbohy-drates. If a flounder a secondary consumer!eats the shrimp, the flounder gains only 10calories of the original 100 calories o foodenergy, because the shrimp will have used up 90calories in living,

Biologists often represent the flow of energyin an energy pyramid. With its broad base, steepsides, and narrow peak, the pyrainid reprintsthe loss of energy through the trophic levels.The ecosystem can support many printaryconsumers, such as rabbits and shrimp, becausethey eat plants. Remember that plants are lowon the energy pyramid and most of the sun' senergy has not yet been lost in the form of heat.However, the ecosystem is abl.e to supportrelatively few tertiary consumers, such aswolves or speckled trout, at the peak, I3ecause ofthe energy lost and the large amount of foodenergy required to sustain large predators, thereis not enough energy to support a grea t nuinberof them.

Louisiana Life in Coastal Marshes

Louisiana's saltrnarshes and freshwatermarshes play an important part in Louisiana'seconomy, According to recent figures from theU5. Army Corps of Engineers, Louisiana wet-lands produce 517 million worth of furs andhides and $680 million worth of commercial fishand shell fish annually. In addition, $299 million

a re spent each year on boating and sportfishingand $38 mtllion on waterfowl hunting. The furand hides produced reprint 25 pencent of thenation's entire harvest. Louisiana has the largestcoastal fin fishery and shell fishery in the coun-try, producing two billion pounds of fish andshellfish annually. This represents 30 percent ofthe nation's annual commercial harvest. Thewetlands are the wintering ground for two-thirds of the duck~ and geese that migrate southdown the Mississippi flyway each year. Themarshes provide recreational opportunities forthe sportsrnan. The associated revenues fromlicense and taxes on recreational equipmentsupport state-sponsored programs. Louisiana'scoastal wetlands and offshore waters produceabout one-sixth of the nation's oil and one-thirdof its natural gas.

The Louisiana coastal zone is a remarkableeographic feature. Preserving and protecting itor its natural bt~uty, commercial and recre-

a tional value, and cultural heritage is a responsi-bility for aII of us.

Froblems with Louisiana Coastal Marshes

Coastal marshes were formed by deltaicgrow th in the eastern part of the state. In thewestern part of the state, coastal marshes wereformed from sediments produced primarilyfrom the erosion o f deltas. The sediments weretransported by westward oceanic currents andadded to sediments transported from rivers.The Mississippi River has been the major sourceof sediment. It has a! tered its course a t least sixtimes over 7/NO years, crea ting major del tacomplexes from the Mississippi-Louisianaborder to the Vermilion Bay in south centralLouisiana. As the river builds, a delta expandsfarther and farther out into the shallow shelfareas of the Gulf of Mexico, However, as newland builds, the Mississippi's course becomeslong and inefficient. It then seeks a shorter pathto the Gulf, because water always seeks the pathof least resistance. This course change starts anew delta forming in a different location, Theold deltaic lobe, no longer actively fed by riversediment, slowly subsides as its soft sedimentscompact, leading to erosion and, finally, deterio-ration and disappearance. With new deltasalways building, there was continual net marshgain until the early 1900s when the MississippiRivets flow was finally contained by levees.

Before the Europeans came, native Ameri-cans were adapted to the changing Louisianacoastline, Their lifestyle was migratory and theymoved from place to place as the landscape of

Louisiana regularly changed. Later settlersarrived and built structures that allowed forregular flooding, but the pioneers wanted toown and use the land's na tural resources, AsEuropeans, they were used to static conditions,expecting land that existed today to exist tomor-row, They were unfamiliar with Louisiana'sdynamic landscape, which is unlike most otherparts of the United States, They wanted theMississippi to stay on the same route, so theycould build cities and farins. Thus, the battle tocontrol the Mississippi began and is still continu-ing today.

Historically, the river's sediment load flowedinto the wetlands and nurtured the marshes.While the lower Mississippi River has beenleveed to some extent for about 250 years, thelevees were privately built and maintained, Theriver often broke through these low poorlyconstructed levees. The U.S. Army Corps ofEngineers succeeded in contaming all the riverwithin the levees and floodways in Louisianaafter the devastating flood of 1927. Today, theriver deposits most of its sediment load in thedeep waters of the Gulf of Mexico beyond thecontinental shelf, thereby losing much of itspotential for crea ting new marshes in shallowerareas,

Leveeing is not the only problem, Man isaccelerating the natural subsidmg and erodingprocess of old deltas. Access canals for oil andgas drilling, pipelines, and navigation channelsall contribute to this loss. Depending upon howthis dredged material is deposited onto themarsh vegetation, it could enhance or be de-structive to marshes gf it is blown, it will actu-ally build marsh.!. Dredging to form andmaintain these canals removes sediment fromthe marshes. However, spoil banks piled-updredged material! can prevent the free flow ofsediment-carrymg water through the marsh.Also, the na tural tidal channel is hal ted by thespoil banks, and nutrients from the ocean are nolonger available for the vegetation. Without theebb and flow of the tides, saltmarsh plants andsurrounding soil are never exposed to the air.This exposure is necessary because it allows forthe release of toxins that build up in water-logged conditions. Without this release,saltmarsh plants sicken and die. When theplants die, the soil erodes, and open water is left.

Another activity that can affect marsh loss isthe extraction of oil and gas, which can lead toland subsidence. As these materials are re-moved, a sinking of the soil occurs. Bank ero-sion causes the widening of canals and natural

wate~ay' Boat k~ .shi gag., st thban& c n cause unprotected canals to double inwidth in as few as 20 years

The one exception to this land loss isring at the mouth of the Atcha falaya River. Atpresent, 30 percent of the Mississippi's waterand sediment is diverted by the Old RiverControl Structure into the Atchafalaya Ri ver.This diversion has increased delta formation inAtchafalaya Bay, While Atchafalaya delta is thefastest growing and largest new delta in NorthAmerica, the new delta is not enough to offsetland loss in other coastal rnarshes,

Wetland loss in Louisiana is caused by acombination of natural and man-made influ-ences. Wetland loss would be occurring regard-less of human intervention. Remember, amature delta is abandoned by the MississippiRiver, and without the input of new sediments,the land subsides, However, with the changingof the Mississippi a new delta and new wetlandsare formed in another part of the state.

Man has interfered with the natural deltaiccycle. Sy Leveeing the Mississippi, the river cannot change course and create a new delta. Inaddition, man's activities have increased loss inthe already existing deteriorating coastal wet-lands.

Freshwater Marshes

Few peopLe realize the iinportance of fresh-water marsh resources to the early settling ofAmerica. Trappers in search of beavers andother furbearers that w ere abundant inLouisiana rnarshes mapped rivers andoutposts. These outposts la ter grew inments such as New Orleans, Baton RoNatchitoches. Settlers utilized the fresmarshes' natural resources to feed, closhelter them.

Too often, though, marshes w«e "mosquito-infested wastelands to be useddumping grounds for trash or to be "iproved" � that is, drained or filled forture or construction. Drainage had be

early as the settlement of New Orleans in 1718,and alterations of freshwater marshes and othet"v;et lands have since been carried out on amassive scale.

This loss is prevalent here because ~uisianais richly endowed with wetlands. As much as 40percent of the wetlands in the lower 48 states arein Louisiana, and this state is experiencing thegreatest wetland loss. One of the first values offreshwater rnarshes observed was the marshes'importance as habitat for wildlife, particularlywaterfowl, As wetlands across the nation weredestroyed, populations of ducks and geesedeclined. By l956, the U.S. Fish and WildlifeService had developed a wetlands classificationbased on their value to wildlife and instituted

programs to protect environmentally sensitivewetland areas.

Ecology

A freshwater marsh, unlike a swamp, is anarea dominated by nonwoody, or herbaceous,plants. Often the vegetated areas are inter-spersed with patches of shallow water. Marshesmay be flooded for all or only part of the year.However, they must be flooded enough tosustain vegetation that is adapted to living inwater-logged condi ttons � plants like cattails,reeds, arrowhead, and pickerelweed, SeeFreshwater Marsh Poster.!

Freshwater marsh communities includehabitat for a variety of plants and animalsadapted to live in wet conditions. A habitatprovides the food, shelter, water, and space anorganism needs to survive. For example, a sac-au-lait needs small insects to eat, submergedvegetation in which to hide from predators,water to live in, and enough room to have aterritory. A freshwater marsh can providehabitat for sac-au-lait, bass, and many other fishspecies. Numerous birds, such as songbirds,wading birds, and waterfowl, nest and raisetheir broods among the vegetation. Manyrnarnmals, such as deer, muskra t and nutria, livein the marsh or visit to feed, The exact plantspecies composition of any particular marshdepends on many things, including geographiclocation, water chemistry, depth of water,duration of the flooding season, and climate.

Hood Control and Water QualityAt first, wetland preservation was focttsed

on protecting wildlife habitat. Now people arediscovering that wetland preservation canprovide some alternative solutions to watersupply problems, Flood control is a natural

function of marshes, Their soils and vegetationact as natural "sponges" that ha ve a tremendousability to absorb and retain excess water. Thisstorage capacity can save the adjacent areadownstream from flood damage. In addition,the presence of wetlands along shores andriverbanks helps to protect those areas fromerosion. Root systems of the plants hold soil thatwould otherwise be washed away.

Some of the excess flood water stored inmars hes evapora tes, while, some may be fedslowly into streams. Still more of the water mayseep underground to recharge the water table.This recharge depends on the soil layers be-tween the marsh and the groundwater, Wherethe soil is permeable allows water to flowthrough spaces between the soil particles!, waterwill seep through This recharge is important,especially where groundwater is being pumpedout to supply human needs such as in BatonRouge. When marshes are destroyed or pavedover, rainwater instead of being held andslowly seeping into the ground water supply!runs off into str'earns and is no longer availablefor use.

Besideshelping to re-charge the watersupply, wetlandsfunction as a filter,removing somepollution andsediment fromthe water. Be-cause the wet-lands slow andhold the water,sediment par-ticles such assand, silt, andclay can settleout. Excessnutrients inthe water from agricultural nm-off are brokendown by bacteria and other microbes and ab-sorbed by the marsh plants.

When wetlands areas are developed bydraining, dredgmg, fillmg, or channelization,wastes are no longer purified by normal biologi-cal functions. This can result in pollution of thewater supply. Some marshes can even processhuman waste as long as nutrient loads are notexcessive and the contents are not too toxic.However, large amounts of pesticides or heavymetals would overload any ecosystem andthreaten the health of the marsh.

Saltwater Marshes

Saltmarshes can be found in many coastalareas where the land meets the ocean, Coastal

saltmarshes contain flat, soggy land riddled bysmall channels of water, During each tide,saltwater floods the channels and soaks into thesoiL Organisms in these wetlands must adapt tothe rigors of constant change. Temperature,salinity, moisture, and available oxygen fluctu-ate as the marsh is constant! y flooded anddrained.

While few species can tolerate these chal-lenges, the plants and animals that have adaptedcan grow abundantly. Plants such as cordgrassand glasswort have special adaptations such asglands for eliminating excess salt. Animals havetheir special adaptations too. During low tide,fiddler crabs and clams burrow into sand andmud for shelter. Barnacles close their shellstightly to keep from drying out. See SaltmarshPoster.!

Salt marshes are among the world's mostproductive ecosystems. Marsh productivitybegins as the sun's energy is captured by marshplants. The plant roots hold the thick shiny mudof the salt marsh and this encourages the growthof other plants such as algae and phytoplankton.When the plants are eaten, the energy is trans-ferred to other organisms. Animals that eat theplants in an ecosystem benefit frown the energyand nutrients that are stored in the plants. Inturn, these animals are eaten by wading birdssuch as the great blue heron, whose diet includesfish, crabs, and worms, As the plants andanimals in the wetland die, bacteria growing inthe mud act as decornposers, freeing nutrlentsand making them available once again for otherplants, algae, and bacteria.

The Detrital Food Web

Marsh plants can also support abundantanimal life. Only a few animals feed directly onhving cordgrass. More often, the organic mate-rial in these plants is con-sumed after the plants die,when it is broken downinto detritus. Detritus isplant material enrichedwith bacteria. Fiddlercrabs, snails, insect larvae,bacteria, dams, and evensome fish such as mullet and menhadenfeed on the detritus. Tides carry some of the richdetritus from marshes into adjacent shallowoceanic areas where it enriches the productive

bottom-dwelling communities tha t includeoysters, clams, worms, mudworms, plankton,and fish.

Wildlife

Many birds and mammals find food andshelter in the saltmarsh. Muskrats and nutriasfeed directly on the plants. Other animals, suchas raccoons, otters, and minks come in search ofcrabs and mussels. Marshes also provide feed-ing and resting stops for migrating and winter-ing birds. Other nonmigrating birds nest inmarshes where they eat insects, snails, crabs,and small fish and raise their young.

Saltmarshes provide temporary habitats formany creatures that live out most of their liveselsewhere, They function as nurseries for ma-rine animals that inhabit offshore areas asadults, Young shrimp, redfish, speckled trout,menhaden, and flounder grow into adults in thesaltmarsh. Striped bass may rest and acclimatethere on the way to upstream spawninggrounds, as do many of their juveniles on theway to the ocean. When the marsh is coveredwith water at hightide, fish and shrimp swim inlooking for food. The movement of the tidestransports eggs, larvae, and young animals frombays to salt marshes.

Augmenting the high productivity of thesaltmarshes is a special condition called the"energy subsidy of the tides." Some animalspecies, instead of foraging for their food, are fedby the tides' ebb and flow. Filter-feeders, suchas clams, oysters, and barnacles, siphon foodfrom the water as every tide brings in a richsupply of detritus. These marsh organismsexpend less energy to find food and thus havemore energy available for growth and reproduc-tion.

Conclusions

Because the wetlands are vttai to wildlifeand to human life, we should be prudent in ouruse and conservation of these valuable re-sources. These areas are blessed with an abun-dant beauty. Citizens can push for legislation tofurther protect the wetlands with laws to limitthe creation of new canals and waterways. Thebest way to help curtail our rapid loss of marsh-lands is to divert the nutrient-rich rivers backinto our marshes. Projects to do this are cur-rently underway, Some existing canals can beclosed and filled. Harsh penalties can be as-sessed for the illegal dumping of pollutants intowaterways or for other actions that result inwetland destruction. Legislative bodies canencourage new technologies through economicincentives. These and other measures are neces-sary so that we may conserve our remainingwetlands.

GLOSSARY

Carnivore - A meat ea ter.

Consumer -Organisms that arenot capable of producing theirown food. They are dependentupon getting their energy fromeating producers or other con-sumers,

Community - Ail the plants andanunals in a particular ecosystemthat are bound together by foodchains and other interrelationships.

Detritivore - An organism thatfeeds on dead, decaying organisrris.

Decomposer - Bacteria and fungithat convert dead organisms intoorganic ma terials.

Ecosystem - A natural unit thatincludes living and nonliving partsinteracting to produce a stablesystem in which the exchange ofmaterials between living andnonliving parts follows pa ths, Allthe living things and their environ-ment in an area of any size linkedtogether by energy and nutrientflow.

Energy - Ability to do work and cause changes.Energy Flow - The flow of energy through anecosystem.

Energy Pyramid � A diagram that illustrates theflow of energy through the trophic levels,Food Chain - Transfer of food energy fromplants through a series of animals.

Food Web - A combination of many food chains.Herbivore - A plant eater.

interdependence - The interrelationships ofwildlife with one another and with the variouselements of their environment.

Life Cycle - The developmental path an organ-ism goes through from birth to adult,

Marsh - An environment where terrestrial andaqua tic habitats overlap.

Omnivore - An animal that eats both plants and

animals. Photosynthesis - Process of plants bywhich sugars and carbohydra tes aremade from water and carbon dioxideusing sunlight as an energy source.

Predator - An animal that kills andeats other animals.

Prey - Animals that are killed andeaten by other animals.

Primary Consumers- Animals that eatplants.

Primary Producers � Organisms thatare able to manufacture food fromsimple organic substances,

Secondary Consumers - Animals thatea t prima ry consumers.

Tertiary Consumers - Animals thateat secondary consumers.

Trophic level - Organisms that play asimilar role in an ecosystem.

Marshes EverywherePURPOSE

The Freshwater Marsh and SaltmarshPoster provides an opportunity for students toobserve and identify the ecological componentsof any marsh. Marshes are a vital component ofthe life cycle for many species. This assignmentcan be done individually but we recommendthat two or three students be assigned to a groupfor this activity.

PROCESS OBJECTIVES

Students will be able to Improve their skiHsin observing, inferring, classifying, and recogniz-ing various species by:

1, Identifying common inhabitants of bothfreshwater and saltwater rnarshes.

2. Hlustrating the various trophic levels of afood chain.

3. Combining food chains to create a food web,

4. Comparing ecological relationships ofvarying species.

5. Illustrating how an economically importantspecies such as shrimp fits into the ecosys-tem.

6. I:hscussing the fiow of energy and matterthrough an ecosystem.

Marsh/Saltmarsh Poster or have the entire classlook at the poster. The class size wiH determinethe teacher's choice of arrangement for theexercise.

The poster and foHowing questions will helpdirect the students attention to the complexity ofliFe in wetlands. The students will be a! identi-fying consumer types such as herbivores, carni-vores, and ornnivores, b! exploring simplepredator/prey relationships, and c! construct-ing food chains as well as food webs usingtypical marsh organisms found in the poster.

The teacher should teach the backgroundinformation especiaHy the General MarshEcology section! if the students are not familiarwith the following concepts: predator, prey,herbivores, omnivores, carnivores, food chain,food web, trophic level, energy flow, energypyramid, and decomposers.

MATERIALS

A Freshwater Marsh/Saltwater Marsh Poster

ConceptsEcosystem, marsh, food web, community,

energy production, energy flow, interrelation-ships, interdependence, primary producer,primary consumer, secondary consumer, tertiaryconsumer, decomposers, herbivore, carnivore,omnivore, life cycle, photosynthesis.

Curriculum Guide Reference

Life Science Curriculum Guide �984!:Bulletin 1614, obj. 13, 14a, 14b, ! 5, 26b, 31, 38, 40,81, 82, 84c, 84e, 85,

METHOD

This activity is a cooperative learning exer-cise, The teacher can have a work station forgroups of students to look at the Freshwater

PROCEDURE

FoHow the directions for both the freshwatermarsh and the saltwater marsh sides of theposter.

List four predators and their prey.2. Each student should create a simple food

chain from the marsh scene with at least fourtrophic levels. You can include man in yourfood chain.

3. Identify all the different trophic levels in thefood chain.

Teacher's Answers to the Evaluation Questions

Freshwater Marsh

Student answers will vary.Mink - Duck

Pickerel frog - daxnselflyMasquitofish - mosquito larvaeFreshwater mussel - scud

Student answers will vary,Duckweed � mallard � mink � ma n

A food chain can include a primary pro-ducer, a primary consumer, a secondaryconsuxner, and a tertiary consuxner. Some-tixnes a student will find a quarternaryconsuxner.

Student answers will vary,Producers, herbivore, carnivore, and omni-vore

The sun provides the needed energy forplants and animals to live.

Energy pyramids will vary depending on thetypes of food chains drawn.

Student answers will vary.Duckweed � pumpkinseed � manDuckweed � xnosquito larvae � pumkin-seed � man

Student answers will vary.

Muskrats contribute to freshwater marshloss, In Louisiana, the nutria also contributesto marsh loss.

10. One.

11. Three

12. The salt in saltwater can dehydrate amphib-ians and their eggs.

k redwinged blackbirdI. frog 13, Three.

Identify which organisxns are herbivores,omnivores, and carnivores in your foodchain.

What role does the sun play in the foodchain?

Draw an energy pyramid for your foodchain,

Sketch a food chain, with man at the fourthtrophic level, and another chain with man atthe fourth trophic leveL Use a pumpkin-seed at the third trophic level in your fresh-water marsh food chain. Use the flounder atthe second level in your food chain for thesa ltmarsh.

8. With all the food chains each person inthe group created, make a food web byconnecting all the plants and anixnals youcan from the food chains. Make sure youadd the decomposers,

9. Which of the organisms may contribute tofreshwater xnarsh loss? Can you think af anyanixnals not shown in the poster that contrib-ute to marsh loss in Louisiana? Explain.

10. How many reptiles are in the poster?

11. How many amphibians are in the poster?

12. Why are amphibians rare in saltmarsheswhen they are numerous in freshwatermarshes?

13. How many differen t crustaceans can youlocate? Explain what benefit there is tohaving a shell in a saltwater marsh?

14, Which associated species might be affectedby the loss of xnosquitos in a freshwatermarsh? Which associated spedes might beaffected by the loss of shrimp in thesaltmarsh?

15 What would be the effect of the loss ofproducers?

16 How can aver-harvesting of any of thespecies in the poster affect the food web?What would happen to the energy flaw ifcertain species became extinct?

EVALUATION

Have each student draw a food web using asmany of the organisms in the following list as heor she can connect. Have the students justifytheir connections.

a. crabb. Sxnall bass

c. shrimpd. copepodse. large perchf. crayfish

clamsraccoon

i, mosquitoj. man

rn. heronn. hawko. muskra t

p. dragonflydeer fawn

r. alliga tors. crabt. xnuskra t mound

Salbnarsh

EXTENSIONS

Not applicable.

10. None.

11. None.

14. Mosqui to larvae are food for many fish suchas the mosquitofish. When they becomeadults, mosquitos are food for many speciesof birds.

15, If the marsh lost all the producers, the foodweb would collapse. All animals would die.

16. While many species have alternative foodsources, some species are specialized to one,Thus, these specialized species may die froman insufficient amount of energy and nutri-ents.

Student answers will vary,Laughing gull - minnowsRed winged blackbird � grasshopperWinter flounder � shrimpBarnacles - amphipods

Student answers will vary.Saltmarsh cordgrass detritus � shrimp�Hounder � man

Student answers will vary.Froducer � detritivo~rnivore � omni-vore

A food chain can include a primary pro-ducer, a primary consumer, a secondaryconsumer, and a tertiary consumer. Some-times a student will find a quarternaryconsumer.

The sun provides the needed energy forplants and animals to live.

Energy pyramids will vary depending on thetypes of food chains drawn

Student answers will vary,This can't be done because flounders arecarnivores and cannot eat plant material.Therefore, Aounders canno t occupy thesecond trophic level reserved for primaryconsumers such as herbivores ordetritivores!.

Student answers will vary.

12. The salt in saltwater can dehydrate arnphib-ians and their eggs,

13, Seven. A shell can protect the animal frompredation and prevent excessive drying outduring low tides.

14- Many fish, crab, and bird species depend onthe shrimp as a food source.

15, While many species have alternative foodsources, some species are specialized to one.Thus, these specialized species may die froman insufficient amount of energy and nutri-ents.

l6. lf the marsh lost aII the producers, the foodweb would collapse, All animals would die.

Students can be assigned to write a report onindividual organisms, discussing theirhabitat, feeding habits, and any specialadaptations.

Have students research predator-preyrelationships, Is man a predator or a prey?Can the students think of any situationwhere man is a predator? What about aprey? Talk about the role of diseases in afood web,

Have students create their own marsh scenesusing the cut-and-paste method.

Research the economic aspects of variousspecies indigenous to Louisiana, Rernem-ber to find out how the over-harvesting orunder-harvesting of a species would affectany ecosystem.

Discuss the importance of the role of thedetritivores in the saltmarsh.

FiSh Fo r A FaOg Cb~iII

PURPOSE

Mh game provides a fun meth' for devel-oping a thorough urrderst ~<ng of ~ cha tns.In addition, students will ha ~~ty to«velop some f d chains that are common inLouisiana salt- and f ~hwater marsh

PROCESS OBJECTIVES

Students will be able to develop and im-prove their skills in observing, inferring, classi-fying, recognizing number relations, cornmuni-cating, predicting, and decision-making by:

1, Identifying comrncrn organisms in aLouisiana freshwater marsh and saltmarsh.

2. Illustrating the various trophic levels of afood chain.

3. Combining trophic levels ta form a Foodchain.

4. Discussing the flow oE matter through anecosystem.

5. Consolidating the food chains into foodwebs.

Conceptsfood chain, community,

terreia ti onstu ps Interdependence, troph icevel, primary producer, Prima 7 consumer

o~~ consumer, tertiary consumer, herbi-vore, carnivore, orrrnivare-

Curriculum guide H.c f erenceC~cuium Guide �984!:

Bulletin 1614 obj. 13' 181, 82, 84c, 84e, 85,

METHOD

This activity is a card game that helps stu-dents learn to identify Louisiana food chains.Groups of three or four students will be able todevelop believable Eood chains by drawing and

rdtng cards from a deck of 52 playingcards, Each playing card represents one trophiclevel within a food chain,

The first person with a believable handconsisting of a sun card, a primary producercard, a primary consumer card, a secondaryconsumer card, and a tertiary consumer cardwins, An example of a believable freshwatermarsh food chain is a sun card, a pickerelweedcard, a mosquito card, a frog card, and a blueheron card. An unbelievable food chain mayconsist of a sun card, a pickerelweed card, araccoon card, a frog card, and a blue heron card.This food chain is unbelievable because a frogwould not eat a raccoo~ under any circum-stances. While this is a c!earrut example, it maybe necessary to research a particular animal' sfood habits if a discrepancy arises,

At the teacher's discretion, the winner maybe required to identify the types of consumerswithin the trophic levels in his food chain beforean official winner can be named. For example, aprimary consumer might be a herbivore or anomnivore Clues are provided on the playingcards.

There are two different decks, one withplants and animals typical of a Louisianasaltmarsh, the other with plants and animalstypical of a Louisiana freshwa ter marsh. Manyof the plants and anbnals can be found withintheir appropriate habitats on the FreshwaterMarslb'Saltrnarsh Foster,

MATERIALS

There are two different decks of cards. Oneis for freshwater marshes, the other is for salt-marshes, In each deck, masters are provided tomake 52 cards necessary for each group of threeor four players. All the plant and animal sheetsmust be copied twice to create the deck of 52cards. To avoid confusion, duplicate the twodifferent decks of cards on differently coloredpaper. This wiII simplify separating the cards incase they get rruxed together.

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PROCEDURE

Make sure each deck consists of four suns, 16producers, 14 primary consumers, l4 secondaryconsumers, and four tertiary level consumers.Cards can be duplicated, glued onto rectangle-shaped heavy stock paper, and laminated fromthe masters provided at the back of this activity.

1. The teacher reproduces the playing cardsprovided and glues them to rectangle-shaped heavy stock paper. Laminate them ifpossible. Make sure each group has aII 52playing cards containing the right propor-tion of trophic levels, for either freshwatermarshes or saltmarshes.

2. A student deals out five cards to each playerand himself and places the rest of the cardsface down in the center.

3, The dealer then takes the top card from thedeck. He must discard either the card pickedup from the top of the deck or one from hishand and place it face up in the discard pile.

4. The next player can take the top card on thediscard pile or a card from the top of thedeck He checks his hand and must discardone card,

harvest ducks, geese rabbits, fish, mussels,«-bearing animals, and turtlessal trna rsh, we harvest seafood such as crabs,oysters, shrimp, and mussels. Other speciesman harvests include waterfowl, fur-bearinganimals, and fish such as flounder, redfish,and speckled trout.

Diagrams will vary fram group to group.Most illtroduced species do not survive,though some do, These species often haveno predators and they quickly populate anew area. Native species can be crowded-out by the introduced species.If man over-harvests one species in a foodchain, then the higher trophic or higherconsumer! levels have no food. Without anyfood source, the transfer of energy andnutrients stops and those organisms die,However most animals are not dependent ona single food source. While over-harvestingof a species wiII put a strain on the food web,most species will switch to an alternativefood source. However, if a species is special-ized to feed on that one food source, then apart of the food web might be lost because oflack of food.

5. The game continues until one person gets ahand consisting of five cards that wouldconstitute a believable food chain. If astudent declares a winning hand and thefood chain is unbelievable, that student mustwait out two turns before he can draw acard.

6. At the end of the game, have the studentsconnect their food chains inta a food web.

EVALUATION

l. Describe where man fits into a food web.

2 Have the students diagram a food webcommon to a Louisiana freshwater marshand a saltmarsh.

3. Discuss the impact on a food web if manintroduced a species that had no predatorsinto an ecosystem.

4. What is the impact on a food chain if inanover-harvests one species? What about in afood web?

Teacher's Answers to the Evaluation Questions1. Humans are an intricate part of most wet-

land food webs, In a freshwater marsh, we

EXTENSIONS

1, Students can be assigned to write a one-pagereport on the prey of certain Louisianapredators,

2, Have the students connect commonLouisiana food chains into a food web for afreshwater and saltwater marsh. Keep thegrowing food webs on a piece of posterboard and add to them during the year asyou talk about new Louisiana plants andanimals.

Have students describe the predator-preyrelationships within the food chains. Whathappens when a predator or prey is in-creased or decreased?

Have students research the extermination ofsome of Louisiana's top predators. Ex-amples are the red wolf and the panther,Could we reintroduce these predators today?What happens to the balance of the food webwith the loss of a species.

Give a real-life example of what happens tp afood web when man upsets the balance byunder-harvesting a species, over-harvesonga species, or introducing an exotic species

Energy Is There EnougTo Go Aroung?PURPOSE

Energy � Is There Enough To Go Aroundyh an achvity am~ at developing a thoroughundersta ding of energy flow and loss and theimpact of energy rnovernent in a food web.

PROCESS OBJECTIVES

Students wrII be able todevelop or improve their skillsin observing, inferring, classify-ing, recognizing number re4-tions, recognizing space/ timerelationships, communicating,predicting, and decision-making by:

1, Hlustrating the varioustrophic levels of a food chain.

2, Comparing ecological relationships ofvarying species.

3. Determining the extent of energy loss amongorganisms within a food chain.

4. providing an example of energy loss amongorganisms within a food chain,

5. Comparing the stability of a food web withthe stability of a food chain.

6. Discussing the impact of altering the balanceof a food chain or a food web.

Concepts

Ecosystem, marsh, food chain, energy pro-duction, energy flow, interrelationships, interde-pendence, trophic level, primary producer,primary consumer, secondary consumer, tertiaryconsumer, photosynthesis

Curriculum Guide Reference

Life Science Curriculum Guide �984!.-Bulletin 1614, obj. 13, 14a, 14b, 15, 26b, 31, 38, 4081, 82, 84c, 84e, 85,

METHOD

sing jellybean models, students weal m th-timlly d~~e the loss of ~ergy through

a simplified food chain.

MATERIALS

One hundred jellybeans for the first demon-stration that involves four students �0 morejellybeans for any additional demonstrations!,four large paper cups, a knife

PROCEDURE

1, Hold up a jar of 100 jellybeans. Explain tothe students that the 100 jellybeans represent100 units of energy from the sun that isphotysynthesized by plants. Teil yourstudents to imagine that each jellybean energy unit! is energy available for plantsand animals to live and reproduce. Havethem visualize that 90 percent or 900jellybeans! of the sun's energy that reachesthe earth is never utilized by plants. For amore detailed account refer to GeneralMarsh Ecology in the unit's backgroundinformation.

2. Four students each receive a paper cup anddecide who wiU represent phytoplankton single-celled plants!, zooplankton single-celled animals!, a minnow, and a flounder.

3. Cormt 100 jellybeans and put them in thephytoplankton's cup. That is the amount ofenergy the phytoplankton photosynthesizedfrom 100 units of energy from sunlightreaching the earth.

4. The phytoplankton may consume 90 of the100 jellybeans photosynthesized. lf theteacher desires, the students do not have toeat the jellybeans.! This represents theenergy burned up in tissue maintenance plants release carbon dioxide as a wasteproduct into the a ir during respira tion!,growth, and reproduction. The 10 jellybeansleft over represent the energy that is storedin the plant's tissue from the original 100units of the sun's energy that the phyto-plankton photosynthesized, Tha t energy isavailable for any consumer.

5. The zooplankton eats the phytoplanktonand receives the 10 units of energy �0 jellybeans!. The zooplankton may consume nineunits of energy. As in plants, the nine unitsof energy nine jellybeans! are burned up in

EVALUATION

EXTENSIONS

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growth, tissue mamtenance animals releasecarbon dioxides as a waste product into theair during respiration!, or reproduction. Theremaining one energy unit is stored as fat orin body tissue. This is the energy availablefor any higher level consumer.

The minnow eats the zooplankton andreceives the one jellybean. With the knife,divide it into 10 parts. The minnow mayconsume nine of those parts. The other tinypart of jellybean one-tenth! left is theamount of energy available for any higherlevel consumer.

The flounder eats the minnow and gets theone-tenth of a jellybean. The model startedout with 100 units of sun and the flounderreceived one-tenth of an energy unit.

How many of the 100 energy units that theplants photosynthesized did each organismin the food chain receive?

What happened to the remainder of theenergy from the level before?

How much of the original 100 uni ts ofenergy that the p4nts photosynthesizedfrom the sun would reach man if he caughtand ate the flounder?

How much more energy would the minnowreceive if it directly ate the phytoplankton?lf a human wanted to be energy efficientwhat part of the food chain should he eat?What happens in a food chain if the phyto-p4nkton dies?

What hap pens in a food chain if the flounderdies?

Why do biologists show energy loss in theshape of a pyramid?Why is "energy loss" important toknow about if we want to help feedthe world's human ever-growinghurna n popu4 tion?

Teacher's Answers to the Evaluation QuestionsThe phytoplankton received the 100 units ofenergy, The zoop4nkton received 10 unitsof energy. The minnow received one unit ofenergy. The Hounder received one-tenth of aunit of energy.

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The energy was used in tissue maintenance,growth, and reproduction.

The man would receive one-hundredth of aunit of energy.

The minnow would receive 10 times moreenergy.

Humans should eat the phytoplankton.All the organisms along the food chain willdie eventually if' the phytoplankton dies,lf the flounder dies, the organisms below onthe food chain will still survive.

Because energy at each trophic level is lostthrough tissue maintenance, growth, andreproduction, there is less and less energya vailable for the next level of the food chain.

Even if aII humans became vegetarians herbivores!, the world could still onlysupport as many people as there was food.There is a limit to the number of people thatcan survive on this p4net

What happens to the How of energy tospeckled trout if man overharvests theshrimp population?What happens to the flow of energy if manintroduces an exotic plant such as waterhyacinth into the food web? Water hya-cinths are not eaten by herbivores.Discuss man's need for energy to do workWhat kinds of energy are humans rurmingout of today? Talk about the advantages anddisad vantages of solar energy to run a city.In the past, scientists were trying to build aperpetual motion rnachine. Applying whatyou have learned about the flow of energy,discusa the reason a perpetual motion ma-chine is not possible.

Alligator

FRESH

Swell ow

Swallows eat mosquitos.

Sun

The beginning of the food chain.

Alligators eat raccoons, pickerel, andsm a11 snappi ng t urt 1 e s,

Sun

The beginning of the food chain.

Mussel

No squi to larvae

Scud

FRESH

Mu ss el s eat phd t o pl ank ton and de tri tu s d e a d p l ant m a t e ri a 1 !.

tiosquito larvae eet phgtopl ankton anddetritus deed plant material!.

Scuds eat copepods and ostracods.

Rabbi t

Rabbits eet live plant material.

Blue Gill

Blue gills eet insect larvae,

Nosqui tof i sh

Mosquitofish eat mosquito larvaeand scuds.

RaccoonMosqui to

Pi ckerelHarsh Hawk

FRESH

Raccoons eat small painted turtles,mussels, and baby rabbits.

Giant Water Bug

Gi ant wa ter bugs ea t small minnows,

Harsh hawks eat muskrats, rabbits,and raccoons.

Female mosquitos feed on the blood ofrabbits, muskrats, and raccoons.

Snapping TurtleSnapping turtles eat small minnows.

baby muskrats, and small paintedturtles.

Pickerel eat giant, water bugs,sac-au-1 ai t, and mo squi t of i sh.

Millet

DuckweedPickerel weed

FRESH

Cattail

Cattails roots are eaten bg muskratsand nutrias.

Bull tongue

Bulltongue contributes to the detritalfood chain. It is eaten bg zooplankton,

insect larvae, and mussels.

Pickerelweed roots are eatenbg nutriasand muskrats, The seeds are eaten bg

ducks and geese.

Millet seeds are choice duck and geesefood

Willow

The leaves are eaten btI deer.

Duckweed is eaten bg duck~

Ph g topi ank'ton

Painted turtle

FRESH

Algae are eaten bg zooplankton, insectlarvae, and rnus sel s.

Copepod

Copepods eat algae and phtjtopiankton

Painted turtles eat plant material.

Phgtopionkton is eoten Dg zooplankton.insect larvae, ond mussels

Ostracod

Ostracads eat. algae ond phgtoplankton.

Muskrat

Muskrats eot cot oils ond pickerel weed

Sea Otter

Sea otters eat any type of fish. crabs,mussels, and oysters.

Seagull

Seagulls eat crabs, menhaden, killifish,and silversides.

Sun

The beginning of the food chain.

Sun

The beginning of the food chain.

Raccoon

Speckled TroutFlounder

SALT

Snowg egret

Snowy egrets eat any srnrrll fish

S i 1 vers l d e

Si lversides eat zooplankton

F I oun de rs eat s il vers i des, menhaden,and k i 1 1 | f i sh.

Raccoons can eai, rnussels, grasshoppers,and tilue cr atjs

Ghost Crab

Ghost crabs eat mussels and oysters

Speckled trout eat silversides, menhaden,and killifish

MenhadenS hrimp

Musse1s Brown Pelican

SALT

Shrimp eat detritus deed plant materiel!

Mussels eat phgtaplenkton, algae,end detritus deed plant materiel!.

Predatory Spider

Predatory spiders eat grashoppers

Menhaden eat phgtopl ank tonend al gae.

Brown pelicans eat fish such es

shad and menhaden.

Oyster Drill

oyster drills eet oysters

Grasshopper

Shad

SALT

Needlegrass

Need legras s is part of the detri tal foodweb. It is eaten bg sea cucumbers,

pe ri w i o k 1 as, mu s se I s, c I am s, an d shrimp

Zooplankton

Zooplankton eat phgtopl ankton.

Shed eat phgtoplankton and algae

Sa1 t marsh Bulrush

Saltmarsh bulrush is part of the detrital

food web It is eaten bg menhaden, shad.mullet, and clams.

Grasshoppers eat live plant mater>al

Polgchaete

Polgchaetes eat detritus dead plantmaterial�!.

Smooth Cordgrass W1 r89rass

Gl as sw ortSeagrass

S8lt GrassPhgtoplenkton

SAI T

Smooth cordgrass is a part of thedetrital food chain in a saltmarsh. it is

eaten bg blue crabs, shrimp, male crabs,coquinas, pol gchae te s, and snails.

Glasswort is part of the detrital food

chain. It is eaten bg oysters, crabs,coquinas, mussels, polgchaetes, snails,

and c I am s.

Salt grass is part of the detrital foodchain in a saltmarsh. It is eaten bg sand

dollars, snails, sea cucumbers, andmussel s.

Wiregrass is part of the detrital foodweb. it is eaten bg menhaden, mullet,

and shrimp.

Seagrass is part of the detrital food web.It is eaten bg periwinkles, sand dollars,

and zooplankton.

Single-celled plants that live in thewater. They are eaten bg menhaden,

mussels, and barnacles,

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