Aquatic Ecosystems

¾ of earth is covered by water Two types of aquatic ecosystems: Freshwater ecosystems Marine ecosystems

Freshwater Ecosystems Only 3% of water is freshwater Two main divisions: –Flowing (rivers, streams) –Standing (lakes, wetlands, estuaries)

Rivers and Streams Originate in mountains/ hills Turbulent – little plant life

Rivers and Streams Middle course Plants can grow as river slows down and sediment builds up

Rivers and streams Lower course River meanders Beavers, otters, etc found here

Guess which river? Mississippi Euphrates Rhine Amazon

Guess which river? Mississippi Euphrates Rhine Amazon

Guess which river? Mississippi Euphrates Rhine Amazon

Guess which river? Mississippi Euphrates Rhine Amazon

Standing Water Lakes, ponds, wetlands, estuaries Phytoplankton (single- celled algae) form the base of many food webs

Wetlands An ecosystem in which water is present at/near the surface for at least part of year Bogs, swamps, marshes

Estuary Where river meets sea Nurseries for many fish/ shellfish

Marine Ecosystems Label the diagram of the marine ecosystem as we go

Photic and aphotic zones Photic zone: where light penetrates - photosynthesis occurs here –(200 meters down) – phytoplankton!!!!!! Aphotic -permanently dark - Algae/phytoplankton rich in photic zone

Photic or aphotic?

Divisions based on depth/distance from shore: Intertidal Coastal Open ocean

Intertidal – between the tide zones Organisms are exposed to water and air

Coastal – from low tide to edge of continental shelf Shallow enough to be mostly photic zone Coral reefs in warmer waters – HUGE biodiversity

Coastal – from low tide to edge of continental shelf Shallow enough to be mostly photic zone Giant kelp forests in colder waters (can grow 50 cm/day!!)

Open Ocean Largest zone From coastal edge and out Up to 11,000 meters (7 miles) deep Frigid temps High pressure Total darkness

Benthic Zone: the ocean floor

Benthic Zone – Ocean floor Benthos = organisms living on ocean floor