Two Key factors in determining what organisms can live in certain aquatic ecosystems:• Dissolved Oxygen (DO) Levels• Water Temperature – Cold water has more dissolved oxygen than warm water – DO levels are related to water temperature – Who needs oxygen? • All the marine animals…yes, fish need oxygen too!!!
Streams and Rivers• Organisms are adapted to seasonal changes in water level and rate of flow• Rivers change from source point to end point (where they empty out, usually ocean) – Source: usually cold (water is from springs), low in nutrients and clear • shallow and narrow • few phytoplankton • major producers are algae on rocks in river bed • Arthropods in benthic zone that feed on algae and leaves • Common fish is trout – Downstream from source • Wider and deeper • Marshes and other wetlands • Warmer and murkier water • Phytoplankton • Frogs, catfish, insect larvae
Ponds and Lakes• Water bodies with very little dissolved salt• Standing water• Photic zone: surface of water – Phytoplankton and water plants that use photosynthesis• Aphotic zone: no light/little light – Light levels too low to support photosynthesis – Benthic zone • Rock, sand, sediment • Floor
Plankton• Phytoplankton – Unicellular algae – cyanobacteria• Zooplankton – Planktonic animals that feed on phytoplankton
Wetlands• Aquatic ecosystem where water covers the soil or is present near the surface of soil for at least part of the year• Water may be flowing or standing, salty, or brackish• Very productive ecosystem• Four types
Small depressions where water collectsLots of mosses Bogs
•Covers much of southflorida•Unique•Water from Lake EvergladesOkeechobee flows to theGulf of Mexico and Atlantic•Wet season (May toOctober)•Dry season (November toApril)•Unique Wildlife•Endangered species
Estuary •Wetlands where rivers meet ocean •Mix of fresh and salt water (brackish) •Affected by rise and fall of ocean tides •Many are shallow •Photosynthesis plays a major role even in benthic zone •Primary producers are plants and bacteria, who use both photosynthesis and chemosynthesis •Estuary food webs differ from other ecosystems because primary production is not consumed by herbivores •Most organic material enters food web as detritus •Detritus: made of tiny pieces of organic material that provide food for organisms at the base of the estuary food web •Clams, worms, and sponges feed on this •Support large biomass •Fewer species than fresh water ecosystems •2 types
Salt MarshSalt tolerant plants above low tide lineSea grasses underwaterFound along eastern North America(Maine to Georgia)Chesapeake Bay in Maryland
Coastal estuaries found intropical regionsHawaii and FloridaSalt tolerant trees(mangroves)Sea grassesPrevalent in Everglades Mangrove Swamp
Zones of Marine ecosystems• 2 Main Divisions Based on Light – Photic • 200 m • photosynthesis – Aphotic • Permanent darkness • chemosynthesis• Depth/Distance Divisions – Intertidal Zone • Rocky • zonation – Coastal Ocean (neritic zone) • Low tide mark to outer edge of continental shelf – Open Ocean (pelagic zone) • Edge of continental shelf and outward • 500m to 11000m • Largest division – Benthic Zone • Ocean floor • Attached organisms…
Hydrothermal Vents • Depth of 2,500 meters • Spots on the ocean floor where hot gases and minerals spew out of Earth’s crust from its interior • No sunlight (aphotic) • Producers are prokaryotes that use chemosynthesis to make hydrogen and sulfur containing compounds into carbohydrates they can use • Tube worms (up to 3m long!) and clams feed on these prokaryotes
Coral Reefs• Biologically diverse• Equivalent to the tropical rainforest but the watery version• All invertebrates are found here – Sponges, sea anemones, worms, star fish, mollusks, sea urchins• Vertebrates also roam the reefs – Sea turtles and tropical fish• Reefs are formed from colonies of coral polyps – Animals in the Phylum Cnidarian (Jellyfish phylum) • These organisms secrete hard exoskeletons made of calcium bicarbonate that make up the hard, stone like base of the reef • This is the home to many coral polyps, sponges and algae • Coral polyps use photosynthesis During the day to make their own food • Coral polyps also have stinging tentacles to help them capture zooplankton
Zones of Marine ecosystems• 2 Main Divisions Based on Light – Photic • 200 m • photosynthesis – Aphotic • Permanent darkness • chemosynthesis• Depth/Distance Divisions – Intertidal Zone • Rocky • zonation – Coastal Ocean/neritic • Low tide mark to outer edge of continental shelf – Open Ocean/pelagic • Edge of continental shelf and outward • 500m to 11000m • Largest division – Benthic Zone • Ocean floor • Attached organisms…
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