Aquatic Ecosystems

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!!!

What type of Freshwater ecosystem are these?

Flowing Water

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

Organisms adapt

What type of fresh water ecosystem is this?

Standing Water Ecosystem

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

Name this marine ecosystem…

Fresh water Wetlands

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

Bogs

Small depressions where water collectsLots of mosses

Marsh

Marsh

Shallow wetlands along riversGrass-like plants in waterLooks like river of grass

Swamp

Swamp

Water is slowly flowing through these wetlandsLooks like a flooded forest

Name this ecosystem(hint: unique to Florida)

Everglades

• Covers much of south florida

• Unique• Water from Lake

Okeechobee flows to the Gulf of Mexico and Atlantic

• Wet season (May to October)

• Dry season (November to April)

• 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 Marsh

Salt tolerant plants above low tide lineSea grasses underwaterFound along eastern North America (Maine to Georgia)Chesapeake Bay in Maryland

Mangrove Swamp

Coastal estuaries found in tropical regionsHawaii and FloridaSalt tolerant trees (mangroves)Sea grassesPrevalent in Everglades

Marine Ecosystems

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…

Name this Marine Ecosystem

Intertidal Zone

ZONATIONprominent horizontal banding of organisms in particular

habitat

Coastal ocean (Neritic)

Kelp Forests

• Pacific Ocean• Cold, nutrient rich water• Support many organisms• Grow up to 50 feet tall!

Open Ocean Ecosystem (largest)(Oceanic/Pelagic)

• Phytoplankton drifting in photic layer• Zooplankton-feed off phytoplankton• Whales, squid, dolphins

Benthic Zone

• 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

Hydrothermal Vents

http://images.google.ca/imgres?imgurl=http://www.spacesciencegroup.org/sootw/graphics/oceanlifezones3.jpg&imgrefurl=http://www.spacesciencegroup.org/sootw/Default.asp?Theme=earthscience&pagename=oceanlifezones&h=150&w=199&sz=8&hl=en&start=28&um=1&tbnid=WHh5ccVD-twflM:&tbnh=78&tbnw=104&prev=/images?q=ocean+zones&start=18&ndsp=18&svnum=10&um=1&hl=en&safe=active&sa=N

Coral Reefs

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…