APES Chapter 7 Aquatic Ecology

Plankton

small plant organisms (phytoplankton) and animal organisms (zooplankton) that float in aquatic ecosystems

Phytoplankton

small, drifting plants, mostly algae and bacteria, found in aquatic ecosystems

Zooplankton

small floating herbivores that feed on phytoplankton

Nekton

strongly swimming organisms found in aquatic systems

Benthos

bottom-dwelling organisms

Decomposers

organisms that digests pats of dead organisms and cast-off fragments and wastes of living organisms by breaking down the complex or organic molecules in those materials into simpler inorganic compounds and then absorbing the soluble nutrients; return most

Euphotic Zone

upper layer of a body of water through which sunlight can penetrate and support photosynthesis

Coastal Zone

warm, nutrient-rich shallow part of the ocean that extends from the high-tide mark on land to the edge of a shelflike extension of continental land masses known as the continental shelf

Tributary

a stream or river that flows into a larger river

Estuary

partially enclosed coastal area at the mouth of a river where its fresh water, carrying fertile salt and runoff from the land mixes with salty seawater

Impervious Surface

promotes runoff of precipitation volumes instead of infiltration into the subsurface; the imperviousness or degree of runoff potential can be estimated for different surface materials.

Intertidal Zone

area of shoreline between low and high tides

Barrier Islands

long, thin, low offshore islands of sediment that generally run parallel to the shore along some coasts

Coral Reefs

formation produced by massive colonies containing billions of tiny coral animals, called polyps, that secrete a stony substance (calcium carbonate) around themselves for protection. When the corals die, their empty outer skeletons form layers and cause th

Open Sea

part of an ocean that is beyond the continental shelf

Freshwater Life Zones

aquatic systems where water with a dissolved salt concentration of less than 1% by volume accumulates on or flows through the surfaces of terrestrial biomes

Lakes

large natural body of stranding fresh water formed when water from precipitation, land runoff, or groundwater flow fills a depression in the earth create by glaciation, earth movement, volcanic activity, or a giant meteorite

Glaciation

the process whereby glaciers form and spread

Eutrophication

physical, chemical, and biological changes that take place after a lake estuary, or slow-flowing stream receives inputs of plant nutrients - mostly nitrates and phosphates - from natural erosion and runoff from the surrounding land basin.

Oligotrophic Lake

lake with a low supply of plant nutrients

Eutrophic Lake

lake with a large or excessive supply of plant nutrients, mostly nitrates and phosphates

Drainage Basin

(watershed) land area that delivers water, sediment, and dissolved substances via small streams to a major stream (river)

Floodplain

flat valley floor next to a stream channel. For legal purposes, the term often applies to any low area that has the potential for flooding, including certain coastal areas

Riparian Zone

thin strips and patches of vegetation that surround streams; they are very important habitats an resources for wildlife

Hydric Soil

soil that is filled with water between the spaces

Riffles

stretch of shallow, fast, rough water flowing between pools in a stream; low nutrient content but high oxygen content; organisms need constant oxygen saturation; oxygen gotten from water moving over rocks folding oxygen into water