Marine Biology Vocabulary

Brackish

Water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. Occurs when freshwater from a lake or river meets the salty seawater of an ocean body.

Hydrogen bonding

Specific heat

The amount of heat in calories required to raise the temperature of 1g of water by 1 degree C

Salinity

The concentration of eight major ions

Stratification

Division into layers

Thermocline

The region of temperature change between the upper, warm layer and the lower, cooler layer

Infrared radiation

Angle of incidence

Light attenuation

Benthic

Associated with the bottom

Pelagic

Associated with the open water

Photic zone

The zone in between the euphotic and disphotic zones

Euphotic zone

Has sufficient light for photosynthesis

Aphotic zone

No visible sunlight

Turbidity

The measure of relative clarity of liquid. Influenced by the amount of inorganic particles in the water

ALAN

Artificial light at night

Phytoplankton

Photosynthetic microbes

Sediment

Inorganic matter, either from runoff or resuspension

Pycnocline

A layer in the ocean or other body of water in which water density increases rapidly with depth

Halocine

pH

Primary productivity

Solubility

The maximum amount of a substance that can dissolve in a liquid under specified conditions

Deep chlorophyll maximum

Ocean acidification

Disphotic zone

Not total darkness, but not enough light for photosynthesis (up to 800m)

Epipelagic

In a thermally stratified water mass, this is also the area above the thermocline

Organic matter

Dead phytoplankton, fecal matter, etc.

Wave

Periodic motion of water driven by wind, gravity, or a disturbance (earthquake, landslide, etc.)

Current

A continuous, directed movement of water. They’re driven by tides, wind, thermohaline circulation, and the Earth’s rotation

Tides

Very long-period waves that move through the oceans in response to the forces exerted by the moon and sun.

Tsunami

A wave created by a disturbance that displaces a large amount of water (e.g., earthquakes or landslides). These waves can surpass heights of 20m/~66ft.

Wave crest

Wave trough

Wave period

The time it takes to complete one full tide cycle.

Neap tide

Occur during the first and third quarter moon, when the moon appears “half full.” When the sun and the moon are at right angles to each other, the bulge of the ocean caused by the sun partially cancels out the bulge of the ocean caused by the moon.

Spring tide

Occur during full or new moons—which occur when the Earth, sun, and moon are nearly in alignment. The gravitational pull of the sun is “added” to the gravitational pull of the moon on Earth, causing the oceans to bulge a bit more than usual.

During these tides, the average tidal ranges are slightly larger. High tides are a little higher and low tides are a little lower than average. These tides occur twice each month.

King tide

A colloquial term used to describe an especially high tide event. A full or new moon when the moon is closest in its elliptical orbit.

Storm surge

Storm tide

Ocean acidification

Rogue waves

A wave whose height exceeds twice the significant wave height. The first real recording of a wave of this type was the Draupner wave. There is currently no way to predict the individual occurrences of this type of wave.

Kelvin wave

A large-scale wave whose motion is strongly influenced by Earth’s rotation (the Coriolis effect) and a boundary such as a coastline or the equator. They transport energy, heat, and sea level anomalies over very long distances. This type of wave can take 2-3 months to cross the tropical pacific.

Flood current

When a tidal current moves toward the land and away from the sea, it “floods.” These are also affected by the sun and the moon.

Ebb current

When it moves toward the sea away from the land, it “ebbs.”

Eddies

An area of swirling ocean.

Upwelling

Winds blowing across the ocean surface often push water away from an area. Water rises up from beneath the surface to replace the diverging surface water.

Downwelling

Surface water is pushed downwards.

Thermohaline

Gyres

Large systems of spinning currents caused by the Coriolis effect. There are five located in the North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean.

Trade winds

Wind blowing steadily towards the equator, from the tropical high-pressure belts to the low-pressure zone at the equator.

Atlantic meridional overturning circulation (AMOC)

Tidal current

The vertical motion of the tides near the shore causes the water to move horizontally, creating currents.

Gulf stream

An intense, warm western boundary current in the western North Atlantic Ocean. It moves north along the coast of Florida and then turns eastward off North Carolina, flowing northeast across the Atlantic.