Primary Productivity and Ocean Currents Discussion

Primary productivity

the rate at which organisms convert solar energy into organic compounds, or biomass, through photosynthesis

High latitudes

Hours of sunlight varies greatly with season, making sunlight a limiting factor of 1° productivity.

Low latitudes

Hours of sunlight are constant, and nutrients are a limiting factor of 1° productivity due to a permanent thermocline that prevents mixing of water layers.

Mid latitudes

Sunlight varies with season, and a temporary thermocline develops in summer.

Trophic structure

different levels of organizations in a food chain based on how much energy they consume

10% rule

In energy transfer within trophic structures, typically only 10% of energy is passed from one trophic level to the next.

Ocean currents

Surface currents are generated by prevailing winds and influenced by the Coriolis Effect, while vertical currents are caused by density differences among water masses.

Gyre

Huge, circular-moving current systems that dominate the surfaces of oceans, with five main gyres: North Pacific, South Pacific, North Atlantic, South Atlantic, and Indian Ocean.

Coriolis Effect

The pattern of deflection taken by objects not firmly connected to the ground as they travel long distances around the Earth.

Coastal up-welling

Occurs when coastal winds combined with the Coriolis Effect cause surface water to move away from shore, replaced by cool and nutrient-rich water from below.

Deep ocean circulation

Caused by density differences among water masses, where denser water sinks and spreads out beneath the surface.

Thermohaline Circulation

Also known as conveyor belt circulation, it is driven by differences in temperature and salinity in ocean water.

Shoreline

The line that marks contact between land and sea, which is a dynamic environment that migrates with the tides.

Canada's shoreline

Canada has the longest shoreline in the world, measuring 151,019 miles.

Shore

Extends between the lowest tide level and the highest elevation on land affected by storm waves.

Coast

Extends inland from the shore as far as ocean-related features can be found.

Foreshore

The area exposed when the tide is out (low tide) and submerged when the tide is in (high tide).

Backshore

The landward area of the high tide shoreline, usually dry and affected by waves only during storms.

Nearshore

The area between the low tide shoreline and the line where waves break at low tide.

Offshore

The area seaward of the nearshore zone.

Beach

An accumulation of sediment found along the landward margin of an ocean or a lake, characterized by a gentle slope and composed of locally abundant material.