EVS 411 Exam 1

Thermocline

transition layer between the warmer mixed water at the surface and the cooler deep water below, associated with depth.

Types of ocean circulation

subsurface flow and surface currents

Subsurface flow

flow of water below earths surface, driven mainly by differences in density due to changes in salt, salinity, and temperature

Surface currents

wind driven

Primary forces for surface currents

start H2O moving and impact velocity. thermal, expansion/contraction, density differences, and wind stress (major driver of SC)

Secondary forces of surface currents

impacts direction and nature of flow, coriolois effect, gravity, friction, and basin shape

oceanic gyres

circular systems of ocean currents that are driven by wind, earths rotation, and land masses

How are tidal currents mixing?

moon pulls water up, creating high tides and when the moon moves away → low tide

tidal currents (low tide)

low water level

tidal currents (high tide)

water pushing in an nutrients begin to circulate and move out

Ekman transport

Wind-induced movement of water at the surface being transferred to layers below

Downwelling

wind blowing from the north and towards the shoreline (Northern Hemisphere)

Upwelling

wind blowing from the south and away from the shoreline (Southern Hemisphere)

coral bleaching

occurs when water gets too warm, leading to algae leaving, resulting in bleaching.

euphotic

sufficient light for PS. where continental shelf is and most marine animals reside

disphotic / twiligh

insufficient light for PS; sufficient for animal responses. perfect for animals who have eyes for visual cuesand some bioluminescent organisms.

aphotic

no light of biological significance from the surface

photo-inhibition

occurs when organisms are too close to the surface

photoadaptation

organisms adapt to lower light intensity. pigment concentration, number of cells and photosynthetic units

Biogeochemical cycles

in the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the earths crust

solubility is greatest when:

low temperature, high pressure, and low salinity

calcification

carbonate saturation depth changes depending on pH. increasing due to the ocean being more acidic, leading to less fixationof calcium carbonate by marine organisms, affecting their ability to form shells and skeletons.

two forms of CaCO3

calcite and argonite

intertidal zones

zone that is covered by water during high tides and exposed during low tide

intertidal zone habitats

salt marshes, sandy or gravel beaches, and rocky tidepools

spring tide

largest tidal range, full and new moon. distance from the moon has the biggest influence. occurs when the sun and moon are aligned

neap tides

smallest tidal range, 1st and 3rd quarter moon, more narrow

Soft-bottom subtidal

habitat includes all of the unconsolidated substrate areas

rocky subtidal

includes reefs, hard bottom, and kelp forest

red mangrove

outer fringe, large propagules, and salt-excluding species

black mangrove

2nd closest to water, more tolerant to salt than white, and have pneumatophores

pneumatophores

good adaptation for waterlogged sediments. exposed to air most of the time

lenticels

openings on the root that are used to release salt and gas exchange

green algae

fix calcium carbonate, leaves when they die down, tissues that decomposes has calcium carbonate