Aquatic Biomes

Categorized by depth, salinity, temperature, dissolved oxygen

Freshwater : streams, rivers, lakes and wetlands

Marine: estuaries, intertidal zones, coral reefs and open oceans

Rivers & Streams

Originate from underground springs or as runoff from rain or melting snow.

Few plants or algae to act as PP. Inputs of organic matter are from terrestial biomes (falling leaves)

Lakes and Ponds

Standing water. Divided into several zonesLittoral Zone: Shallow area near shore where

emergent plants and algae grow. Photosynthesis occurs

Limnetic Zone: Open water. Rooted plants can no loner survive. Phytoplankton are the only photosynthetic organisms. Extends as deep as sunlight penetrates

Profundal Zone: No sunlight. Producers cannot survive. Bacteria decompose detritus, consuming oxygen in the process. DO levels not sufficient to support large organisms.

Benthic Zone: Muddy bottom of the lake or pond.

Lake Zones

Freshwater Wetland

Swamps: emergent treesMarshes : nonwoody vegetationBogs: acidic wetlands – sphagnum moss

and spruce trees◦Take in large amounts of rainwater and release

slowly into groundwater or streams. Therefore, reducing flooding

◦Filter pollutants◦Recharge groundwater◦Migration and breeding ground for birds and fish

½ of US wetlands have been drained for agriculture or urbanization

SWAMP MARSH

Salt Marshes

Many found in estuaries:◦Where freshwater of a

river meets saltwater of the ocean

Very productive areas

2/3 of marine fish and shellfish spend larval stages in an estuary

Coral Reefs

Found in warm shallow waters

Large diversity of organisms

Great Barrier Reef:◦ 400 sp. Of coral◦ 1500 sp of fish◦ 200 sp of birds

Coral Bleeching: Algae inside the coral dies. w/o the algae the coral die, turning the reef white.

Coral Bleeching

Intertidal Zone

Coastline between high tide and low tide

Lowtide:Organisms have a high tolerance for exposure to direct sunlight, high temperatures and desiccation.

Hightide: Organisms must anchor themselves against the force of wave motion

Open Ocean

Open Ocean

Euphotic Zone: Upper layer of the ocean with available sunlight. Phytoplankton found here. Rich in DO. Many large predatory fish. Low in nutrients (unless ‘upwelling’ area)

Bathyl Zone: Mid-layer, twilight, no photosynthetic organisms, Low DO. Small fish and zooplankton.

Abyssal Zone: No sunlight, Plenty of nutrients. “Marine Snow”

The deeper the water : less sunlight, DO and temperature falls

phytoplankton

Ocean food chain