Ecology- Aquatic biomes

process chemical elements and energy from terrestrial systems and transport to oceans

freshwater streams and lakes

flowing water systems such as streams and rivers

logic

fast moving water with coarse particles on the stream bed

riffles

deeper and slower flow, finer sediments

pools

bottom dwellers and include many kinds of invertebrates

benthic

dead organic matter

detritus

substratum below and adjacent to the stream

hyporheic zone

land surface saturated or covered with water at least part of the year

• emergent vegetation

wetlands

stream sizes and patterns, physical conditions and biological communities

river continuum concept

still waters occur where depressions in landscape fill with water

lentic

open water dominated by plankton

pelagic zone

small and microorganism suspended in the water

plankton

phytoplankton restricted to upper layers through which light penetrates

photic zone

non photosynthetic protists and tiny animals

zooplankton

near shore =, photic zone reaches the bottom

• macrophytes occur in this zone

littoral zone

detritus from littoral and pelagic is food for animals, fungi, bacteria

• cold and low oxygen

benthic zone

lakes or ecosystems with high nutrient content and high biological production

eutrophic

contain brown, acidic water with low productivity and low oxygen

dystrophic

lakes with low nutrient content, abundant oxygen, low primary production

oligotrophic

occur where rivers flow into oceans

• salinity varies fresh water from river mixes with salt water

estuaries

shallow coastal wetlands dominated by grasses and rushes

• terrestrial nutrients enhance productivity

• tides produce salinity gradients

• juvenile fish shelter

salt marshes

dominate some tropical coastal zones

• mangroves are salt tolerant, evergreen trees and shrubs, 16 different plant families

• roots trap sediments build up and modify the shoreline

mangrove forests

provide stable substrate for many organisms

• sessile organisms cope with wet and dry conditions

rocky intertidal zones

not very stable, little available food, wave action

• invertebrates burrow

• small organisms live on or among grains

sandy shores

restricted to warm shallow water

• large colonies and algal partners

coral reefs

support diverse marine community

• large brown algae leaf like fonds, stems, holdfasts anchoring solid substrates

kelp beds

submerged communities of flowering plants in subtotal marine sediments

• algae and animals grow on plants, habitat offering

• agricultural activities increase algal growth

seagrass beds

open ocean beyond the continental shelves

• supports highest densities of organisms, extends 200m depth

• energy is supplied by falling detritus

pelagic zone

swimming organisms capable of overcoming ocean currents

nekton

nekton, phytoplankton, zooplankton

pelagic zone organism

sparsely populated, temps near freezing and high pressure

• rich in organic matter and small organisms

• bioluminescence to lure prey

ocean benthic zone

historical overfishing

Jackson et al 2001