Marine ecology exam 1

Marine Ecology

Study of how ocean organisms interact with each other and their environment.

Marine Biology

Study of organisms living in the oceans.

Oceanography

Study of all physical, chemical, biological, and geological aspects of the ocean.

Pelagic Zone

The open water column, encompassing all depths except the demersal layer.

Benthic Zone

The ocean seafloor or bottom substrate.

Neritic Zone

Coastal water column extending from the shore out to 200m depth at the shelf edge.

Oceanic Zone

Open water region deeper than 200m, beyond the continental shelf edge.

Intertidal (Littoral) Zone

Shore region submerged at high tide and exposed at low tide; organisms face desiccation risk.

Subtidal Zone

Region below the mean low tide line that stays continuously submerged.

Photic (Epipelagic) Zone

Sunlit surface layer down to ~200m where photosynthesis takes place.

Aphotic Zone

Ocean layers below 200m that receive insufficient sunlight for photosynthesis.

Hadley Cell

Large atmospheric circulation cell where warm air rises at the equator and falls cold at 30 degrees latitude.

ITCZ

Intertropical Convergence Zone; narrow equatorial band of high rainfall where trade winds converge.

Ocean Gyre

Large circular surface current system; clockwise in N. Hemisphere, counterclockwise in S. Hemisphere.

Thermohaline Circulation

Deep ocean circulation driven by density differences from temperature and salinity (takes ~1000 yrs).

Upwelling

Rising of deep, cold, nutrient-rich water to replace surface waters displaced by wind.

El Niño

ENSO phase marked by unusually warm Eastern Pacific sea surface temperatures and a deeper thermocline.

La Niña

ENSO phase marked by unusually cold Central Pacific sea surface temperatures and a shallower thermocline.

Shortwave radiation

• Net energy gain at low latitude

radiation recieved from the sun

• Net energy loss at high latitudes

longwave radiation

deflected and re-emitted by earth

how is heat redistributed?

winds, evaporation, precipitation

Hadley circulation

-warm air rises by equator, cool air falls by subtropics

-cool air flows back to equator by trade winds

ITCZ

at convergence of Hadley cells

narrow band of intense rainfall

Light Attenuation (loss)

• Most energy absorbed in top 10m

• Wavelengths (λ) attenuated at

  different rates

• Red λs lost first

• Blue λs lost last

• Absorption or scattering by

  suspended particles

Ecological Effects of Light Distribution

• Photosynthetic organisms restricted to surface

• Visual interactions (e.g., predation) in surface layers

• Changes in species colors/patterns

• Bioluminescence in deep, dark water

Thermocline

Layer of rapid temperature change

Surface Mixed layer

layer above thermocline, mixing by winds surface currents, convection

seawater and freshwater freezing

seawater freezes at lower temp

does hot or cold water hold more 02

cold

spring tides

-highest tides

-moon and sun ALIGNED

Neap tides

lowest high tides

moon and sun offset

dinural cycle

once per day

semidinural

twice

mixed semidinural

2 unequal cycles per day

Wave dynamics affect which species inhabit coastlines

Method of attachment

• Rigid structure or skeleton

• Ability to tolerate a highly dynamic environmen