Env. sci. ch._7
- 1. Aquatic EcosystemsAquatic Ecosystems Chapter 7Chapter 7 Environmental ScienceEnvironmental Science
- 2. Freshwater EcosystemsFreshwater Ecosystems • Lakes and PondsLakes and Ponds • WetlandsWetlands • RiversRivers • Factors affecting which organisms live inFactors affecting which organisms live in freshwater ecosystemsfreshwater ecosystems – TemperatureTemperature – SunlightSunlight – OxygenOxygen – NutrientsNutrients
- 3. Aquatic Ecosystem OrganismsAquatic Ecosystem Organisms • PlanktonPlankton – Organisms that float near the surfaceOrganisms that float near the surface – Two typesTwo types • Phytoplankton – produce most food for ecosystemPhytoplankton – produce most food for ecosystem • Zooplankton – microscopic animalsZooplankton – microscopic animals • NektonNekton – Free-swimming organismsFree-swimming organisms – Fish, turtles, whalesFish, turtles, whales • BenthosBenthos – Bottom-dwelling organismsBottom-dwelling organisms – Mussels, worms, barnaclesMussels, worms, barnacles • DecomposersDecomposers – Break down dead organismsBreak down dead organisms
- 4. Lakes and PondsLakes and Ponds • Layers of a LakeLayers of a Lake – Littoral zoneLittoral zone • Top layer near the shoreTop layer near the shore • Nutrient richNutrient rich • Plants are rooted in mudPlants are rooted in mud • Plants make energy from photosynthesisPlants make energy from photosynthesis – Depend on sunlightDepend on sunlight – Benthic zoneBenthic zone • Bottom of the lakeBottom of the lake • Bacteria lives hereBacteria lives here • No sunlight reaches this layerNo sunlight reaches this layer • Dead organisms are consumed by decomposersDead organisms are consumed by decomposers
- 5. Lakes and Ponds,Lakes and Ponds, cont.cont. • EutrophicationEutrophication – Increase of nutrientsIncrease of nutrients – Occurs when a large amount of plant growthOccurs when a large amount of plant growth in a lake or pondin a lake or pond – Increases amount of bacteriaIncreases amount of bacteria – Bacteria uses up oxygenBacteria uses up oxygen – Eventually not enough oxygen for organismsEventually not enough oxygen for organisms – Runoff can accelerate eutrophicationRunoff can accelerate eutrophication • Sewage, fertilizers, animal wastesSewage, fertilizers, animal wastes
- 6. Freshwater WetlandsFreshwater Wetlands • Areas of lands covered in water for atAreas of lands covered in water for at least part of the yearleast part of the year • Two types – marshes and swampsTwo types – marshes and swamps • Environmental FunctionsEnvironmental Functions – Absorb and remove pollutantsAbsorb and remove pollutants – Control flooding by absorbing extra waterControl flooding by absorbing extra water – Provide homes for wildlifeProvide homes for wildlife – Prevent against erosionPrevent against erosion – Provide recreational areas for fishing, etc.Provide recreational areas for fishing, etc. – Provide breeding grounds for fish andProvide breeding grounds for fish and shellfishshellfish
- 7. MarshesMarshes • Occur in low, flat landsOccur in low, flat lands • Have little water movementHave little water movement • Plants root in sediment under waterPlants root in sediment under water – Reeds, rushes, cattailsReeds, rushes, cattails • Water birds have adapted to marshesWater birds have adapted to marshes – Heron – spearlike beak to grab fishHeron – spearlike beak to grab fish – Ducks – flat beak to sift through water for fishDucks – flat beak to sift through water for fish • Kinds of marshes according to salinityKinds of marshes according to salinity – Brackish marshes – slightly salty waterBrackish marshes – slightly salty water – Salt marshes – saltier waterSalt marshes – saltier water
- 8. SwampsSwamps • Flat, poorly drained land near streamsFlat, poorly drained land near streams • Types of swampsTypes of swamps – Mangrove swampsMangrove swamps • In warm climates near the ocean (salt water)In warm climates near the ocean (salt water) – Freshwater swampsFreshwater swamps • Ideal environment for amphibiansIdeal environment for amphibians • Swamps attract birds and reptilesSwamps attract birds and reptiles – Wood ducks, alligatorsWood ducks, alligators
- 9. Human Impact on WetlandsHuman Impact on Wetlands • Wetlands were considered wastelandsWetlands were considered wastelands where insects breedwhere insects breed – Humans drained the wetlands for this reasonHumans drained the wetlands for this reason • Important roles now recognizedImportant roles now recognized – Purifiers for wastewaterPurifiers for wastewater – Flood preventionFlood prevention – Habitats for wildlifeHabitats for wildlife • Most states have laws against theMost states have laws against the destruction of wetlandsdestruction of wetlands
- 10. RiversRivers • Many begin from snow melt in mountainsMany begin from snow melt in mountains – Cold, full of oxygen, fast movingCold, full of oxygen, fast moving • River flows down the mountainRiver flows down the mountain – Becomes wider, warmer, slower, less oxygenBecomes wider, warmer, slower, less oxygen • A river changes depending on the landA river changes depending on the land and climate it is flowing throughand climate it is flowing through
- 11. Life in a RiverLife in a River • MossesMosses – Anchor to rocks with roots called rhizoidsAnchor to rocks with roots called rhizoids • PlanktonPlankton – Live further down stream in warmer waterLive further down stream in warmer water • Trout and minnowsTrout and minnows – Live at the headwaters (strong current)Live at the headwaters (strong current) • PlantsPlants – Some are rooted in the river’s sedimentSome are rooted in the river’s sediment – Leaves will vary in shape depending on river’s currentLeaves will vary in shape depending on river’s current
- 12. Rivers in DangerRivers in Danger • Industries polluting the waterIndustries polluting the water – Kills organismsKills organisms – Makes fish inedibleMakes fish inedible • Runoff from landRunoff from land – Puts pesticides in the river and sedimentPuts pesticides in the river and sediment • DamsDams – Change the ecosystem in and around riverChange the ecosystem in and around river
- 13. AssignmentAssignment • Page 178Page 178 • Section 1 ReviewSection 1 Review • #1-5#1-5
- 14. Marine EcosystemsMarine Ecosystems • Coastal WetlandsCoastal Wetlands – Areas covered by salt water for all or part ofAreas covered by salt water for all or part of the timethe time – Many fish and wildlife live hereMany fish and wildlife live here – Absorb excess rainAbsorb excess rain • Helps to avoid flooding problemsHelps to avoid flooding problems – Filter out pollutants and sedimentsFilter out pollutants and sediments – Are recreational areas for boating, fishing, etcAre recreational areas for boating, fishing, etc
- 15. EstuariesEstuaries • EstuaryEstuary – Area where fresh water from a river mixesArea where fresh water from a river mixes with salt water from an oceanwith salt water from an ocean – Currents form hereCurrents form here • Cause mud and nutrients to fall to the bottomCause mud and nutrients to fall to the bottom • Marsh grasses will begin to grow hereMarsh grasses will begin to grow here – Constantly receiving fresh nutrientsConstantly receiving fresh nutrients • Makes it a very productive ecosystemMakes it a very productive ecosystem
- 16. Plants and Animals of EstuariesPlants and Animals of Estuaries • Rooted plantsRooted plants – Sunlight can reach the bottom since water is shallowSunlight can reach the bottom since water is shallow – Nutrient supply is always highNutrient supply is always high • Plankton live herePlankton live here • Mammals feed on planktonMammals feed on plankton – Dolphins, manatees, sealsDolphins, manatees, seals • Oysters, clams feed on the plantsOysters, clams feed on the plants • All organisms that live here can tolerate variousAll organisms that live here can tolerate various levels of salinitylevels of salinity
- 17. Threats to EstuariesThreats to Estuaries • Ports are built over estuariesPorts are built over estuaries – Provides easy access to oceansProvides easy access to oceans • Usually populated areas surround an estuaryUsually populated areas surround an estuary – Waste is dumped in the estuaryWaste is dumped in the estuary – PollutantsPollutants • SewageSewage • Industrial waste containing toxic chemicalsIndustrial waste containing toxic chemicals • Agricultural runoff containing pesticides, fertilizersAgricultural runoff containing pesticides, fertilizers • Quick LabQuick Lab – Page 180Page 180
- 18. Salt MarshesSalt Marshes • Develop in estuaries where rivers deposit theirDevelop in estuaries where rivers deposit their load of mineral-rich mudload of mineral-rich mud • Clams, fish, aquatic birds live hereClams, fish, aquatic birds live here • Protects young animals when smallProtects young animals when small – ShrimpShrimp – CrabCrab – FishFish – When older, they migrate to the seaWhen older, they migrate to the sea • Absorbs pollutantsAbsorbs pollutants • Protect inland areasProtect inland areas
- 19. Mangrove SwampsMangrove Swamps • Located along coastal areas of tropicalLocated along coastal areas of tropical and subtropical zonesand subtropical zones • Mangrove trees are the main plantMangrove trees are the main plant • Protects the coastline from erosionProtects the coastline from erosion • Reduces damage from stormsReduces damage from storms • Many animals use as a breeding groundsMany animals use as a breeding grounds • Sometimes filled with waste and destroyedSometimes filled with waste and destroyed
- 20. Rocky and Sandy ShoresRocky and Sandy Shores • Rocky ShoresRocky Shores – Many plants anchor to rocksMany plants anchor to rocks – Many animals live on the rocksMany animals live on the rocks • AnemonesAnemones • MusselsMussels • SpongesSponges • Sandy ShoresSandy Shores – Dry out when tide goes outDry out when tide goes out – Tiny organisms live off of planktonTiny organisms live off of plankton – Barrier islandsBarrier islands • Land that runs parallel to the shoreLand that runs parallel to the shore • Protect the mainland and coastal wetlandsProtect the mainland and coastal wetlands
- 21. Coral ReefsCoral Reefs • Limestone ridges built by tiny coral animalsLimestone ridges built by tiny coral animals called polypscalled polyps – They secrete skeletons of limestoneThey secrete skeletons of limestone • Calcium carbonateCalcium carbonate • Thousands of plants and animals live hereThousands of plants and animals live here – Most diverse ecosystem on EarthMost diverse ecosystem on Earth • Live in clear, warm salt waterLive in clear, warm salt water • Live in shallow water so sunlight can reachLive in shallow water so sunlight can reach • They are predators that never chase their preyThey are predators that never chase their prey – Stinging tentacles to capture organisms that float byStinging tentacles to capture organisms that float by
- 22. Disappearing Coral ReefsDisappearing Coral Reefs • Corals die if:Corals die if: – Water becomes too hot or too coldWater becomes too hot or too cold – Fresh water drains into the water near reefFresh water drains into the water near reef – Water is too muddy, polluted or too high in nutrientsWater is too muddy, polluted or too high in nutrients • Causes of coral reef destructionCauses of coral reef destruction – Oil spillsOil spills – SewageSewage – PesticidesPesticides – Silt runoffSilt runoff – OverfishingOverfishing – Careless diversCareless divers – ShipwrecksShipwrecks – Ships dropping anchorShips dropping anchor – People breaking off piecesPeople breaking off pieces
- 23. OceansOceans • AnimalsAnimals – PhytoplanktonPhytoplankton • Live where light and nutrients are (shallow water)Live where light and nutrients are (shallow water) • Have flagella to keep them from sinking deeperHave flagella to keep them from sinking deeper – ZooplanktonZooplankton • Feed on phytoplankton near surfaceFeed on phytoplankton near surface • ExamplesExamples – JellyfishJellyfish – Tiny shrimpTiny shrimp – Larvae of fish, oysters, lobstersLarvae of fish, oysters, lobsters – DecomposersDecomposers • Live on bottom of oceanLive on bottom of ocean • Consume dead organismsConsume dead organisms
- 24. Threats to the OceansThreats to the Oceans • PollutionPollution – Industrial wasteIndustrial waste – SewageSewage – Plant nutrients (fertilizers, etc.)Plant nutrients (fertilizers, etc.) • Overfishing and netsOverfishing and nets – Animals can get tangled in nets and dieAnimals can get tangled in nets and die
- 25. Arctic and Antarctic EcosystemsArctic and Antarctic Ecosystems • North and South PolesNorth and South Poles • Large population of planktonLarge population of plankton • Many fish eat the planktonMany fish eat the plankton • Birds, whales, seals feed on the fishBirds, whales, seals feed on the fish • Fish and seals feed the polar bearsFish and seals feed the polar bears • Antarctic is not populated by humansAntarctic is not populated by humans – Mainly used for research purposesMainly used for research purposes
- 26. Section 2 AssignmentSection 2 Assignment • Page 185Page 185 • #1-5#1-5
- 27. Chapter 7 ReviewChapter 7 Review • Pages 187-189Pages 187-189 • #6-18, 20-26, 29, 34-35#6-18, 20-26, 29, 34-35