BIO225 Aquatic Biology Study Guide 1 Vocabulary

Key vocabulary terms and definitions covering inland waters, ecosystem zonation, stream dynamics, and aquatic properties from BIO225 Aquatic Biology Study Guide 1.

Limnology

The scientific study of inland waters, including lakes, ponds, streams, rivers, and wetlands.

Brackish water

Water that has higher salinity than freshwater, but lower salinity than seawater.

Lentic

Relating to or inhabiting still or stationary fresh water ecosystems such as lakes and ponds.

Lotic

Relating to or inhabiting rapidly moving fresh water ecosystems such as streams and rivers.

Watershed

A scale-dependent area of land that drains all the streams and rainfall to a common outlet.

Continental divide

A naturally occurring drainage divide that separates a continent's river systems into different ocean basins.

Microcosm

A simplified, artificial ecological system created to simulate and study natural environmental processes.

Salt wedge

A layer of denser saltwater that intrudes landward underneath outflowing lighter freshwater in an estuary.

Stream order

A hierarchical measure of the size and branching structure of streams within a river network.

River continuum concept

A model describing the continuous, predictable gradient of physical and biological characteristics along the length of a river system.

Clean zone

The aquatic zone upstream of a pollution source characterized by high dissolved oxygen levels and abundant aquatic life.

Decomposition zone

The polluted stream zone immediately downstream of a waste discharge where dissolved oxygen levels drop rapidly due to organic breakdown.

Septic zone

The severely degraded stream zone where dissolved oxygen reaches its lowest levels, supporting minimal aquatic life.

Recovery zone

The stream zone downstream of a septic zone where dissolved oxygen levels begin to increase and biological life restores.

Autotrophic ecosystem

An ecosystem where primary production via photosynthesis exceeds total respiration.

Heterotrophic ecosystem

An ecosystem where total respiration exceeds primary production, relying on external organic matter inputs.