BIO120 - 3

Freshwater biological zones

freshwater ecosystems connect land and sea

lotic ecosystems

Water gathers into larger streams and rivers

first-order streams

the smallest, source streams at the highest elevations

second-order streams

two first-order streams join together

higher-order streams

two-second order streams join together/ small streams merges

riffles

Fast-moving water flowing over coarse particles, increasing oxygen levels

pools

Slower-moving, deeper areas with fine sediments

main channel

Home to swimming organisms like fish

benthic zone

contains invertebrates, insect larvae and crustaceans live on the stream bed

hyporheic zone

a substrate below and adjacent to the stream where water still flows

riparian vegetation

As streams grow larger, terrestrial vegetation input decreases while aquatic plants and fine organic matter increase downstream

shredders

a feeding adaptation that dominates upstream, consuming coarse organic material

collectors

a feeding adaptation that are more common downstream, consuming fine organic particles

lentic ecosystems

lakes and other still waters that form in natural depressions filled with water

smaller lakes and ponds

nutrient-rich

deep lakes

nutrient-poor

pelagic zone

open water in freshwater

littoral zone

nearshore area in freshwater

benthic zone

lake bottom, coldest part with low oxygen

marine biological zones

categorized by physical locations, relative to shorelines and the ocean bottom

estuaries

where river meets the ocean

salt marshes

Terrestrial sediments from rivers create shallow marsh zones with vascular plants.

mangrove forest

trap sediments, provide nutrients, offer habitat and protect shorelines

rocky intertidal zones

support organisms coping with tides and wave action. These organisms must withstand changing conditions.

sandy shores

appear barren but shelter invertebrates beneath the sand

shallow ocean zones

the most biologically diverse and productive ecosystems on Earth.

coral reefs

found in warm, shallow waters, are built by corals that live in symbiosis with algae. The corals provide shelter, while the algae supply energy

seagrass beds

though flowering plants, grow underwater and provide shelter for marine larvae and microorganisms. Found in sandy or muddy seabeds, they help stabilize the ocean floor.

kelp beds

massive brown algae found in temperate waters, support rich marine biodiversity. They provide food and shelter for sea otters, sea urchins, and other marine life.

light and depth

ocean has different zones based on these

pelagic zone

Deep waters beyond the continental shelves

photic zone

part of the deep ocean that gets some sunlight

aphotic zone

part of the deep ocean that sunlight cannot penetrate and deep-sea creatures adapt to darkness and pressure

benthic zone

or the ocean floor, part of the ocean that is cold and deep

bioluminescence

natural light produced by their bodies to attract prey in the darkness

hydrothermal vents

created by volcanic activity, where superheated water enriched with minerals escapes from the seafloor

chemosynthesis

a process where bacteria use chemicals from the vent water as an energy source