Water Quality Unit 5: Freshwater Ecosystems

freshwater ecosystems

vital aquatic environments characterized by low salt content (e.g., lakes, wetlands, groundwater habitats)

wetlands

(lentic) areas where soil is saturated or submerged for significant portions of the year, support plant life (e.g., marshes [dominated by grasses] and swamps [dominated by trees]

lotic systems

water is moving continuously

streams and rivers

• usually part of larger watershed networks

• higher amount of dissolved oxygen (DO)

riparian zone

area adjacent to river, including vegetation, which stabilizes banks, filters runoff, and provides shades

floodplain

low-lying land periodically flooded by the river, often creating wetlands and supports biodiversity

lentic systems

water is standing still

littoral zone

near shore, lots of light and plants

limnetic zone

open water, light supports plankton

profundal zone

deep, low light/no light

benthic zone

bottom, can host benthic organisms like kelp

photic

zone gets light

aphotic

zones doesn’t get light

watersheds

(drainage basin) a land region where all water drains into a specific body of water (ex: rivers, groundwater, wetlands, etc.)

significance of watersheds

• drinking water (they’re freshwater systems)

• irrigation

• ecosystem

• pollutant filter

threats to watersheds

• excessive irrigation —> watershed can dry up

• pollution —> nutrient runoff, thermal pollution, littering

• habitat destruction, e.g. deforestation

• climate change (floods, droughts)

water quality protection

control runoff, reduce pollutants, monitor contaminants

water supply management

balance use for drinking, farming, industry, and recreation (don’t consume water at a rate that is faster than the watersheds natural replenishing rate)

habitat conservation

preserve riparian zones, wetlands, and aquatic biodiversity

land use planning

regulate urban development, promote sustainable farming and forestry practices