Subtidal benthic systems

Algae location and processes

Grow in and under the ice when light penetrates, invertebrates graze on them

What color is the undersurface of pack ice in antarctica

Colored green

Antarctic sponges

Can have symbiotic diatoms, eaten by seastars, provide habitat

Antarctic organisms

Benthic, filters phytoplankton (bachiopod lamp shell)

Who are the most diverse malacostracan crustaceans?

Amphipods

3 Climate change effects in the arctic

Increase some fish production and shift species, problems for sea ice associated species, increased open water which leads to increase in primary and secondary production

3 Climate change effects in the antarctic

Disruption of sea ice, krill, and invasion of new species

What are kelp beds/forests made up of?

Macroalgae (brown algae)

Kelp forests

Floating surface canopy dominated by giant kelp and bull whip kelp

Kelp requirements

Constant movement, cold temperature preference, nutrients directly from seawater, adequate light, hard surface

Kelp morphology

Holdfast (base), stipe (stem), and frond (blade), pneumatocysts

Ecology of kelp

Grow rapidly, not often grazed (anti grazing compounds), usually just decays or mortality caused by physical factors

Kelp and Urchins

Create barren grounds, kelp can recover 1 year after removal, help from otters

Kelp forest ecosystem services

Food, fertilizer, food additives, pharmaceuticals, algin (thickener), potash (gunpowder until WW1)

Conservation issues kelp forests

Over harvesting

Pollution

Warming ocean temperature

Sea grasses

Marine angiosperms or flowering plants within very shallow water high light and current flow, tropical and temperate oceans

Sea Grass beds

Only 50 species, more in tropics than temperate, NOT algae/seaweeds, soft substrate, foundation species

Seagrass abiotic conditions

Water and sediment movement, sediments= lots of organic matter, light and turbidity, temperature, desiccation, salinity changes

Sea grass biotic factors

Grazing, disease, competition,

Sea grass biological interactions

Protection for other organisms, scallop nursery, enhance larval settlement

Sea grass ecosystem services

Refuge for animals, nursery grounds, sediment stabilization, detrital component, home to commercially important species, carbon storage

Sea grass conservation issues

Decline worldwide, eutrophication (excess N and P favors algae), trawling and dredging, pollution/runoff