Oceans

Ocean Coverage (Surface & Biomass)

• Cover 71% of Earth’s surface

• The largest type of salt water body

• Contain 99% of Earth’s living biomass

Main roles of the ocean (4)

• 70% of oxygen in atmosphere due to oceanic photosynthesis

• Regulates the atmosphere’s chemical composition

• Modifies Earth’s climate and weather systems

• Main food source for >50% of the pop.

Sound

Long body of deep water that connects two seas (inlet)

Gulf

Deep inlet of the sea almost surrounded by land, with a narrow mouth; Larger bays

Bay

Inlet of calm waters with land surrounding it on three sides; Can be found in Gulfs

Strait

A narrow passage of water connecting two large bodies of water

Sea

Large body of salt water defined by the presence of continents

Continental Shelves

Shallow, sloping areas near continental margins

Continental Slopes

Transition between continental shelves and deep seafloor

Abyssal Plains

Large flat areas between 4,000 and 6,000 m (13,000–20,000 ft)

Bathymetry

The process of measuring the depth and topographic features beneath the surface of a body of water

Pelagic

Open ocean ecosystems

Open ocean (pelagic) ecosystems are the most ____ ______ and its open waters cover ___% of Earth’s surface

Geographically extensively; 50%

Mesopelagic Zone

Deep sea with extremely high pressure; Sunlight does not reach here (ends at 3,280 ft)

Surface Ocean vs. Deep Ocean Currents

Surface ocean currents are driven by wind, Deep ocean currents are driven by differences in water density

Gyre

Large circular surface ocean current

Phytoplankton

Microalgae that contains chlorophyll and requires sunlight in order to live and grow.

Pros of phytoplankton (2)

• Produces more oxygen than all the world’s rainforest

• Fundamental basis of the marine food chain

Dinoflagellates vs. Diatoms

• Dinoflagellates move with flagella & are covered with shells

• Diatoms rely on ocean currents to travel through the water & have a rigid structure 

Upwelling

The circulation of water from the seafloor to the ocean surface; stirs nutrients to the surface to feed phytoplankton

Polar Waters

Not thermally layered so upwelling of nutrients is strong; Many organisms migrate here for its nutrients

Harmful Algal Blooms (HAB)

When too many nutrients are available, phytoplankton may grow out of control and form these; Produces extremely toxic compounds

Fishery

Region where fish are caught for human

consumption

Drift Net Fishing

Large nets in the upper reaches of the ocean

Trawling

Drags nets through water column or along seafloor

Longline Fishing

Thousands of baited hooks on lines

Seining

Encircles fish and traps them in a large net

Bycatch

Unwanted organisms caught by industrial fishing methods, which are usually thrown back to sea dead

Hydrothermal vents

Volcanic hot springs that emit mineral-rich water

Salinity

Concentration of dissolved minerals in seawater

As atmospheric CO2 is absorbed by seawater, ____ forms, which makes seawater more _____ (lowered pH)

Carbonic acid (H2CO3) ; Acidic

Mangrove Forests

Saltwater-tolerant coastal shrubs and trees. Found in tropics and subtropics; Nurseries for coral reef fishes and many fish species

Kelp Forests

Marine ecosystem dominated by kelp, water

temp below 68°F, and adequate light

Seagrass Meadow

Shallow coastal ecosystem dominated by flowering plants that resemble grasses