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Ocean Waves

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...

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Wave crest

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highest part of the wave

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wave trough

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lowest part of the wave

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wave height

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vertical distance separating the crest from the trough

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wave length

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horizontal distance between the crest of one wave and the crest of an adjacent wave

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wave period

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time it takes two successive crests to pass a fixed point, such as the piling of a pier

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capillary waves

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smallest of water waves. have periods of less than 1/10th of a second. most readily seen on a flat, calm sea when a puff of wind abruptly disturbs the water surface, creating very tiny, short lived wavelets.

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cat's paw

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the ruffling of the water by a light breeze

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chop

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locally generated waves. have periods of about one second.

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swell

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have periods of about 10 seconds.

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tsunamis

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seismic sea waves. very long periods on the order of minutes and hours.

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seiches

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back and forth sloshing of water in harbors.

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the variety and size of wind-generated waves are controlled by four principal factors

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1. wind velocity 2. wind duration 3. fetch 4. original sea state

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as wind speed increase

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so do the wavelength, the period and the height of the resulting waves

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fetch

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area where the wind is in contact with the sea and is rippling its surface. provided the wind blows long enough and the area of water over which the wind blows

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fully developed sea

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waves can no longer grow in size under the existing wind conditions because the energy

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progressive waves

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wind-generated waves because they travel across the sea surface

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wave-measuring techniques

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metric markings, electrical devices (pairs of wires, etc)

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wave base

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the size of the orbits described by water particles that are influenced by waves drops rapidly with depth below the water surface and is not detectable at a water depth equal to about one-half the wave length. this depth is called...

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Snorkelers and scuba divers escape being pushed around by waves by swimming downward...

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if the wave is 10 meters long they will have to dive a depth of 5 meters in order to reach the wave base, below which there is little or no wave induced motion

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Water depth

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> or equal to 1/2 wavelength

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water depth < or equal to

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1/20 wavelength

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the distortion of water-particle orbits in shallow water

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are greatly compressed vertically into elongated ellipses

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water near sea bottom cannot move in a circular orbit, only "back-and-forth"

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bottom interference changes the shape and speed of the wave and transforms it

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deep-water-wave

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where bottom interactions were absent because the wave base was above the sea floor

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intermediate-water wave

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between 1/2 wavelength and 1/20 wavelength. and then a shallow-water wave where the effects from contracting the ocean floor become important

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a DWW

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is defined as a wave moving through water that is deeper than its wave base, which is one-half its wavelength

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a shallow wavelength

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less than 1/20 the wavelength

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celerity

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speed/ motion of mass

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speed of the wave

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C=L (wavelength)/T (wave period)

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the longer the wavelength and period of the waves

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the faster they travel (only correct for deep-water waves which are not in contact with the sea floor)

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The speed of intermediate and shallow-water waves

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is regulated by water depth because bottom friction

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waves are at maximum sizes depending on

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1. size of the fetch, the wind speed, the wind duration and the sea state

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wave interference

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interaction of several waves

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constructive wave interference

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whenever and wherever several wave crests or troughs coincide

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rogue waves

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unusually large breaking waves that are really composed of several large waves that have merged briefly because of constructive wave interference

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destructive wave interference

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when the crest of one wave coincides with the trough of a second wave in such a way that cancellation results

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seas

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ever-changing wave-interference patterns

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wave steepness

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helps predict when and where waves will become unstable and break. wave height divided by wave length

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breaker

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as waves enter shallow water their height increases and their wavelength-> collapses at the shore

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spilling breaker

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the upper part of the crest becomes oversteepened and "spills" dpwn the front side of the advancing wave, continually breaking and slowly losing its energy across the surf zone

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plunging breaker

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the entire wave front steepens, curls, and collapses or "plunges" forward, releasing much of its energy instantaneously

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surging breaker

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the flat, low waves do not become oversteepened or actually break; instead they move smoothly up and then down the face of the beach, reflecting much of their energy seaward

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the most commin break is the..

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spilling type

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storm surges

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sudden changes of coastal water levels produced by storms. they create deep water near the shore and allow waves to break much farther inland than usual are particularly destructive when they happen to coincide with unusually high tides.

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most devastating storm surges are associated with..

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hurricane winds

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seas, swell and breakers are all

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progressive waves

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standing waves

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do not move horizontally but remain stationary as water moves beneath them. these waves oscillate back and forth about a fixed point

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node

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fixed point, or seesaw with one end raised up to a crest and the other dipped down to a trough

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seiches raise water at one end of a basin/container while

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causing water level to drop at the other side

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antinodes

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the maximum vertical displacement of the water level occurs at the sides of the basin

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opposite of nods where water level does not change at tall

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the antinodes is two ends where you sit and node is pivot point

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a standing wave in a lack, harbor or estuary is called a

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seiche

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seiches become real dangers under the condition of

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resonance

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resonance

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which occurs whenever the period of the force (such as the wind or the tides) that stacks the water on one side of the basin equals the natural period of oscillation of the basin as calculated by the formulas given

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internal wave

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occurs underwater and not at the surface, such waves move along the pynoclines, which are surfaces that separate water masses of different densities

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tsunami

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a series of seismic sea waves that have nothing to do with tides despite their familiar name of tidal waves

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internal waves travel at much slower speeds than do surface waves because

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difference in density between two water masses is much less than it is between air and water

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tsunamis are not caused by tides

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but ar ea series of low waves with long periods and long wavelengths caused by shifting of the seabed- explosive volcanic eruptions, earthquakes or submarine slumping

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a wave is a d

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disturbance that moves along or beneath the sea surface. it is described by its wave height, wavelength, wave period, and celerity

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the size of waves depends on the speed and duration of the wind and the fetch

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large waves are generated by strong winds that blow persistently for an extended period of time across an expansive fetch

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chatoic seas as a result of constructive and destructive wave interference are generated by strong winds in the fetch area

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outside the fetch, waves get dispersed into reguar swells which eventually collapse as shore breakers

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two kinds of motions are associated with sea waves: the movement of the wave form itself and the orbital motions of the water particles beneath the wave.

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at a depth below the water surface equal to 1/2 the wavelength wave motion is no longer detectable -- this level is called wave base

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as waves enter shallow water

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their period remains constant, celerity/wavelength decrease and their wave height increases

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orbital motion of water particles changes from circular shape beneath deep water waves to

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elliptical shape beneath shallow-water waves

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in shallow water, ocean swell slows, refracts and collapses as

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spilling, plunging or surging breaker depending on the bottom gradient of the shore zone

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standing waves are

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stationary waves forms that oscillate up and down about a fixed point called a node

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seiches are

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standing waves in estuaries and harbors that have natural periods of oscillation proportional to the basin length and water depth

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resonance, or the

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the amplification of a standing wave, occurs when the period of the forcing element, such as the tide, approximates the natural period of oscillation of the basin

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internal waves are submarine disturbances that

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travel along pycnoclines in water column. they have much longer periods and wave lengths, greater wave heights, and slower wave speeds than wind-generated surface waves

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tsunami contain a

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tremendous amount of energy, have very long periods and wavelengths. they grow in height in shallow water and flood the shoreline, in some cases causing catastrophic destruction and loss of life.

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tides are

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waves with very long wavelengths-much longer than ordinary wind waves- that cause sea level to rise and fall with extra ordinary regularity. most uniformly varying phenomenon in the ocean..

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tidal range

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wave

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vertical distance between high tide

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the crest

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and low tide

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the trough

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tidal range varies from

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region to region

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diurnal

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(pensacola, FL)have a period of about one day meaning that there is one high tide and one low tide daily.

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semidiurnal

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(Boston, MA) tides occur twice instead of once daily, so that there are two high tides and two low tides each day.

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mixed tides

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(pacific coast) vary irregularly twice daily. these high and low tides are of unequal shape each day in other words, the tidal range (wave height) between successive high tides is variable

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spring tide

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the phase when the tidal range is at a maximum (highest high tide and lowest low tide)

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neap tide

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tidal range is at a minimum (high tide is unusually low and low tide is unusually high)

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spring and neap tides occur twice monthly and vary directly with the phases of the

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moon

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tidal pulse of water anywhere on the Earth is caused by:two principle factors:

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gravitational attraction and centrifugal force

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all masses are drawn to one another and exert a

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gravitational pull

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the strength of gravity varies with

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the distance separating any two masses

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because the moon is much closer to the Earth than the Sun, it has more than

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twice the gravitational effect despite the Sun's immense mass

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The sun is about

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390 times farther away from the Earth than is the Moon.

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the Moon is the main

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regulator of the planet's tides

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tidal bulge

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lunar gravitational force pulling on the oceans causes water to be drawn toward the side of the Earth that faces the moon

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a second tidal bulge exists on the opposite side of the Earth

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this one results from the second important tide-raising factor- the centrifugal effect that arises as the Earth and Moon revolve about each other

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the gravitational force of the moon is

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weaker on the far side of than its near side

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ocean water is drawn toward the move by grav. attraction

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water is also displaced to the side of the Earth that faces away from the moon- mound results from rotation about the center of mass of earth-moon system

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Gravitational attractioncauses

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bulge at facing moon in grav. force and another resultant bulge of water on either side of Earth in centrifugal force- associated with the rotation of the Earth and the MOon about their common center of mass

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equilibrium model of tides

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1. no landmasses or effects of the seafloor, both of which greatly distort the tidal bulges and complicate analysis 2. the waves associated with the tides are assumed to bbe progressive waves 3. the water is assumed to be in equilibrium with the tide-generating forces- grav attraction and centrifugal effect- at all times

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asa point on the earth enters a water bugle, the tide rises,

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as it leaves a water bulge, the tide falls

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declination

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the angle between the Earth's axis and the Moon's orbit around the earth

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depending on declination, different points on the planet's surface pass through various parts of the tidal bulges

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in some places right through their center, in others through their edges

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high latitudes

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diurnal tides

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midlatitudes

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mixed tides

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low latitudes

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semidiurnal

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after one earth day, teh moon has moved forward slightly in its orbit

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so an additional 50 minutes is necessary for a spot on Earth to regain its position relative to the Moon each day

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Thus, the times of high tide and low tide shift forward each day

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tidal oscillations

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Neap tide occurs at

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First quarter and last quarter moon

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Spring tide occurs at

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New and full moon

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Dynamic model of tides

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water is assumed to respond actively rather than passively. consider effects of continents.1) tidal bulges are trapped in ocean basins and move around the Earth as the planet rotates once daily about its spin axis. 2) as the earth rotates from west to east, the tidal bulge of water is forced against the western side of the basin where it piles up and creates a pressure gradient. 3) water flows downslope in response to the pressure gradient and in the Northern Hemisphere is deflected to the right by the Coriolis effect. 4) The deflection causes water to stack up against the southern edge of the basin where the pressure gradient causes currents to reverse and flow northward and bend toward the eastern side of the basin. 5) the final effect of this motion is the creation of a rotary system in which high and low tides occur on opposite sides of the basin and in the Norther hemisphere rotate counter clockwise.

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rotary wave

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tidal bulge becomes this. crest on one side of cup and trough on the opposite side both of which progress around cup. this creates high tides and low tides each day. progressive wave*

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amphidromic system

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which describes a tide that rotates about a fixed node. this circular motion results in part from the Coriolis deflection and occurs in large embayments, in seas and in the open ocean

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cotidal lines

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lines on the map that radiate outward from the node of an amphidromic system (spokes of a bicycle)

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cotidal lines connect

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points at which high tide occurs at the same time of the day.

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tidal range anywhere in the basin is indicated by

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corange lines

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corange lines

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link the points on the water surface that have equal tidal ranges. they appear in amphidromic systems as irregular circles centered about the node

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Northern hemisphere

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counter clockwise (deflection to right)

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Sourthern hemisphere

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clockwise (deflection to left)

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hydraulic currents

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a special kind of coastal current created by the buildup of water at the tidal inlet. result is a water slop. examples: reversing falls of the Saint John River in New Brunswick in eastern Canada.

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tidal resonance

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a condition that arises when the period of a main tidal component almost equals the natural period of the basin. in effect, resonance produces a seiche causing the water to slosh slowly back and forth as a standing wave.

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tidal bore

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a "wall" of water that surges upriver with the advancing tide.

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three factors appear to contribute to the occurrence of tidal bores

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1. a large tidal range, typically greater than 5 meters 2 .a tapering basin geometry 3. water depths that decrease systematically upriver

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under such conditions of a tidal bore

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the incoming tide is constricted by the sides and bottom of the river basin so that the front of the tide steepens and is forced to move much faster than it normally would.

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flood currents

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transfer water toward the coast and the tide rises (landward)

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ebb currents

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flow away from the coast and the tide falls (seaward)

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open ocean

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rotary pattern in response to coriolis effect confined, shallow water near shorelines

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shallow/coastal waters

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back and forth flow patterns

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speed of tide

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c=3.13 square root of water depth m/sec

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the rotary wave completes one circuit

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around the basin in 12 hours and 25 mins (semidiurnal and mixed tides) or 24 hours and 50 mins (diurnal tides)

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tidal resonance results

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when the natural period of a basin, which depends on the basins length and water depth, is very nearly equal to the period of the tides

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tidal resonance produces a

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seiche or a standing wave that may create a tidal range in excess of 10 meters

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electrical power

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can be generated by having the flood and ebb currents flow over specially designed turbines

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marine ecology

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extremely diverse, unevenly distributed on the bottom and in the water column

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ecology

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denotes the study of the interrelationships between the physical and biological aspects of an environment

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benthic province

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sea bottom

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pelagic pronvince

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water column

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pelagic province includes

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the neritic zone, the oceaniczone

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neritic zone

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shallow water that overlies the continental shelves

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oceanic zone

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deep water in the open sea beyond the shelf break

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in the shallow neritic zone

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light tends to penetrate to the sea bottom

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the water column is subdividedinto

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five distinct horizons: epipelagic zone, mesopelagic zone, bathypelagic zone, abyssalpelagic zone, hadalpelagic zone

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epipelagic zone

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surface layer- seasurface to 200 meters

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mesopelagiczone

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200m to 1000m. hardlya trace of sunlight

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bathypelagic zone

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1000m to 2000m.

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abyssalpelagic zone

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2000m to 6000m.

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hadalpelagic zone

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6000m and deeper (deep sea trenches)

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seafloor subdivided in to fiveregions

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sublittoral, littoral, bathyal, abyssal and hadal

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sublittoral

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the floor of the continental shelf, from the beach to the shelf break

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littoral

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(intertidal zone) part of the shoreline between high and low tides

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bathyal

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seaward of shelf break beginning at a water depth of about 200 into a water depth of 2000 m. represents meso and bathy pelagiczones

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abyssal

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2000m to 6000m. 75% of bottom habitats

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hadal

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greater than 6000 m water depth. the deepest sea bottom found beneath the abyssalpelagic and hadalpelagic zones.

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photic zone

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well lit so plant photosynthesis is possible during daylight

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photic zone extends from the water surface down to a depth

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that ranges between 20 and 100 meters

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dysphotic zone

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referred to as the twilight zone, has very low levels of illumination because more than 95% of the sunlight has been absorbed by the water above. photosynthesis in these dim conditions is not possible.

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aphotic zone

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deeper, the vast part of the ocean that is in total and perpetual darkness

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Classification of organisms

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kingdom phylum class order family genus species

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all living organisms are separated into three domains:

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archae, bacteria, eukaryota

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extremophiles

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simple organisms of archae. found in environments with extreme temps, salinities, pressures and only organisms that can live within the thermal vents of deep sea floor

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monera

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includes bacteria. decompose dead plants and animals, secrete powerful enzymes

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protista

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single cell organisms that possess a true nucleus

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metaphytae

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marine plants, some are free floating, others are attached to seafloor and confined to the sallow water/shoreline/inner continental self. red green brown algae

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fungi

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widely dispersed in ocean, not as diverse, common in intertidal zone, help algae from drying up and dying during low tide

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metazoa

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marine animals, numerous and diverse

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plankton

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organisms that drift or swim weakly surprising number engage in vertical migrations

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plankton are divided into

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phytoplankton (plants) and zooplankton (animals)

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nekton

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active swimmers such as fishes, squids, reptiles, birds and mammals (seals, manatees)

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members of the nekton

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possess specialized muscles for locomotion most have restricted range controlled largely by water temp and salinity

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to catch nekton

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trawling gear, purse seine

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to catch benthos

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anchor dredge, grab sampler

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benthos

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organisms that are attached to or move on or beneath the sea bottom

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benthic flora

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plants- attached algae, seed-bearing plants, bottom-dwelling diatoms - require illumination and are therefore restricted to shallow sea bottom of the photic zone

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benthic bacteria and animals

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live at all depths on the ocean floor including the deep-sea treches of the hadal zone

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benthos are divided into

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epifauna and epiflora and infaune

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epifauna and epiflora

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animals and plants that live ON the sea bottom

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infauna

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animals that live in the sea bottom

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temperature

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biologists consider this to be the most important single regulator of the distribution and activity of organisms in the ocean

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isotherms show

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amphipods in atlantic ocean and cannot be in warmer waters

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salinity

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affects marine organisms

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benthos have

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high tolerance to salinity changes due to lack of locomotion

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cooler waters =

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more phytoplankton

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diffusion

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a physical process whereby molecules such as salts move from areas of high concentration to areas of low concentration

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perfume

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diffuses through hair moving down the chemical gradient

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osmosis

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diffusion of water molecules through a semipermeable membrane

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osmoregulation

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regulation of the process of osmosis

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marine fish

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have cellular fluids with salinities that are lower than the salinity of swewater drink large quantities of seawater, urinating infrequently and excreting excess salt ions they would become dehydrated and shrivel up

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freshwater fish

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have bodily fluid compositions that are saltier than surrounding water don't drink water, expel large quantities of dilute urine and absorb salts through gills die by swelling and eventual burst of cell walls

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hydrostatic pressure

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pressure created by the height of a stationary column of water a function of the density of sea water (which depends directly on temperature, salinity and turbidity)

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more than 90% of ocean's plant species

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are algae

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holdfasts

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rootlike masses used only to anchor the plant to the sea bottom

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epitheca

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a lid

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hypotheca

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the mox

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planktoon bloom

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swells producing dense amount of diatoms in cold, nutrient rich water

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theca

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cell wall (dinoflagellates)

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zooplankton consist of

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copepods, tiny crustaceans

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molt

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outskeleton is shed for a newer, larger one

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surface drag

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friction between the moving body and the surrounding water by assuming a shape that minimizes the surface area exposed to fluid

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form drag

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function of the volume of water that must be pushed aside by a moving body,

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turbulent drag

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retarding force that strongly robs speed from a moving object

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caudal fin

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tail fin

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aspect ration

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height of caudal fin squared/area of caudal fin

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aspect ratio for a square fin

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1

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aspect ratio for a narrow, tall fin

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10

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fish that cruise fast, such as tuna and swordfish, have tail fins with high aspect rations

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7+

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speed =

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body length/

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fastest fish have

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long bodies, high beat frequencies and high aspect ratios

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other strategies

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crisp turning maneuvers, and brief darting maneuvers

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vertical zonation

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arrangement of parallel bands that represent distinct communities of benthic organisms

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most dominant organisms in soft substrates of sand and mud are

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infauna. animals that burrow into sediment

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deposit feeders

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obtain food by processing mud and selectively removing organics that are mixed into it- sand dollars

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plants are autotrophs

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meaning primary producers, capable of self-nourishment by synthesizing food from inorganic nutrients

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all other organisms are

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heterotrophs. they require prefabricated food because they are unable to obtain energy directly from the sun (consumers)

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trophic means

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nutrition

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trophic levels

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plants/bacteria - heterotrophs (herbivorous animals) - heterotrophs (carnivorous animals) - decomposers - dissolved inorganic nutrients

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for example

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diatom photosynthesizes and grows eaten by copepod eaten by small fish etc

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long food chains have

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5 or 6 trophic levels

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humans are

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omnivores, organisms that eat both plant and animal

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only about__ percent of energy is transferred from level to level

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10

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animals in the ocean feed in one of five basic ways

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grazers, predators, scavengers, filter feeders, deposit feeders

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grazers

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herbivores that consume plants directly snails, sea urchins, many species of copepods that feed on diatoms, dinos, phyto

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predators

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carnivores that typically hunt animals smaller than they are

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scavengers

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many benthic invertebrates such as crabs and snails that search for dead organic matter

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filter feeders

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obtain food by filtering suspended particles of living and dead organic matter out of water that flows by them- barnacles, mussels, oysters and some infaune and clams

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deposit feeders obtain

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food either nonselectively by ingesting sediment and extracting food particles mixed in mud or selectively by searching for specific bits of mud contained in sediment

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chemosyntheti

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use chemical energy released by oxidation of inorganic compounds to produce food, archae

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primary factors

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solar radiation nutrient concentrations

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secondary factors

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upwelling and turbulence grazing intensity water turbidity

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the most productive areas of the ocean are characterized by

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upwelling- the slow, persistent rising of nutrient rich water toward the ocean surface

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in nearshore and shelf waters, storm waves and strong tidal currents cause a great deal of

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water turbulence- the irregular, chaotic flow of fluids which mixes the water column so that nutrients from the sea bottom are brought to the surface and made available to plants

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water turbidity reduces

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the amount of sunlight that can penetrate the water column

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primary production is quite high in

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-coastal upwelling areas along western edges of landmasses -narrow but long zones of equatorial upwelling in Pacific and Atlantic Oceans -Coral Reefs

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downwelling takes nutrients away from photic zone

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sargasso sea

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most notable coastal upwelling sites

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waters adjacent to Peru, Canary Islands, southwestern Africa

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El Nino

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change in global weather patterns, around christmas, sea surface temperature becomes abnormally warm and nutrient levels decline

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refraction

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wave crests bend and become more nearly aligned with the contours of the shallow sea bottom

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breakers

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waves become oversteepened and unstable then collapse in shallow waters

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types of breakers

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spilling, plunging and surging

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nearshore current

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extends from breaker zone (waves break) across surf zone (where most of the wave energy is expended) to the swash zone (where the beach is covered and uncovered by water with each wave surge)

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berm

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prominent wave-deposited feature of most beaches, sand accumulation and a relatively steep seaward slope

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offshore zone

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open water that lies seaward of the nearshore zone

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backshore zone

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land that adjoins the nearshore zone

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dunes

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broad beaches flanked by these. features are formed by wind blowing sand off the dry part of the beach, a process that represents a debit in the sand budget of a beach system. display smooth, sinusiodal profile

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barrier islands

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large deposits of sand that are separated from the mainland by the water of estuaries, bays and lagoons

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tidal inlets

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water gaps between barrier islands

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moraine

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deposited sediment forming a ridge

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bluffs

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steep cliffs from erosion of glacial deposits by waves

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delta plain

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flat lowland that lies at or above sea level, it is drained by a network of distributary channels

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delta front

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consists of the shoreline and the broad submerged front of the delta, slopes gently seaward and gullied with submarine channels

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river dominated deltas

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at river mouths where waves and tides are ineffective in rearranging the river deposits

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wave dominated deltas

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in coastal areas where wave energy is high relative to supply of river sediments

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tide dominated deltas

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strong ebb and flood currents of the tide rearrange the river sediment into long linear ridges and islands

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jetties

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built to prevent or diminish sand deposition at the mouth of harbors, estuaries and tidal inlets due to the longshore drift of sand

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groins

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smaller and cheaper than jetties positioned on eroding beaches to trap sand artificially and to promote accretion (buildup)

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breakwaters

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barriers built in front of harbors or shorelines, expensive structure with high maintenance costs

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estuary

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located between mainland and barrier island, semienclosed body of water where river water mixes with ocean water

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lagoons

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semienclosed coastal water bodies which receive essentialy no inflow of river water, salty or saltier than ocean water

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moraines/ mounds

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glacial till

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bar-built estuary

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long shore currents that form a sand spit or sand bar across an embayment

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fjords

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long, narrow arms of the sea bordered by steep cliffs becomes anoxic as oxygen gets used up

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tectonic estuaries

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form along coastlines that lie on active plate boundaries, where faulting and folding can create coastal basins that fill up with sea water

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salt-wedge estuary

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when river inflow dominates tide, river dominated system and water column is highly stratified. receive high river discharge, weak tidal currents, low density fresh water floats above bottom layer of high density saltwater. tongue = wedge

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well-mixed estuary

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tidal mixing dominates river input of fresh water, tide-dominated system and water column is well mixed and unstratified.

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flocculation

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clay particles in seawater that stick together and form aggregates then settle to bottom, occurs in salty water, create widespread mud shoals

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partially mixed estuary

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displays weak stratification of water column, relative effects of river and tidal flow vary, different circulation

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estuaries have

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remarkable fertility due to dissolved nutrients, ventilated with oxygen

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where bottoms are rocky

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benthic communities are dominated by sessile filter feeders such as mussels, oysters, sponges, barnacles, and small invertebrates that resemble coral

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mud and sand substrates support an epifauna

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sea urchins starfish and snails and an infauna: clams, polychaete worms

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oysters are

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bivalved mollusks that inhabit the shallow and unpolluted bottoms of estuaries bays and tidal creeks

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subtropical lagoons

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inverse flow and "biological graveyards"

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salt marshes

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tall grasses, marsh grasses rooted in mud, residing in sheltered low energy conditions (between barrier islands) New England

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low salt marshes

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extend from mean low tide to the neap high tide- dominated by cordgrass- no competitive pressure

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high salt marsh

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extends from neap high tide to the level of the highest spring tide, only flooded during unusually high tides and storm surges - high competitive pressure

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rhizomes

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buried rootlike stems that send out roots and grass shoots ass they grow out horizontally

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mangrove

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dominant intertidal plants of the tropics and subtropics, distinctive plant communities, occupy more than 49 million acres of coastal land.

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mangrove swamps

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support an abundant and diverse fauna including mollusks, crabs, fish, birds, lizards, turtles and manatees. intertwined roots called prop roots, thich partially exposed. damaged by hurricanes, inhabited by large sea mammals such as manatees

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serve as

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vital natural resource for juvenile fish, cleanse nearshore, erosional impact of hurricanes

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coral reefs

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organically constructed, wave-resistant, rock structure created by carbonate secreting animals and plants

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consists of

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fragments of shells and skeletons and composed calcium carbonate. in rock form, referred to as limestone. thick limestone base covered by a thin living "skin"

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coral animal itself consists of

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a polyp- the body of the living organism that is housed for protection in a rigid exoskeleton (corallite)

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the bottom of the corallite is divided into compartments by vertical partitions known as

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septa

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imbedded in outer layer of corals flesh is

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zooxanthellae- unicellular plants modified dinoflagellates that uses sunlight to produce food photosynthetically using the metabolic waste products of the coral as nutrients

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coral animal and zooxanthellae

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benefit mutually

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coral polyps provide water and CO2 to the zooxanthellae

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which in turn provide sugar and O2 to the coral

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hermatypic coral

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possess zooxanthellae- flourish in tropical waters

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ahermatypic coral

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do not

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primary regulators for coral reef

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water temp, salinity, water clarity and nutrient levels

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fringing reefs

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form limestone shorelines around islands and the tropical areas of continents

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barrier reefs

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grow farther offshore and are separated from the mainland by a lagoons

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atolls

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found in open ocean, far from land and consist of ring, oval or horeshoe shaped reef structures that enclose a lagoon

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common reef fish

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groupers, angel fish, soldier fish, lion fish, parrot fish

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zooplankton-dominated by arthopods

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such as jellyfish, ctenophores, are gelatinous containing more than 95% water imparting a body density close to that of water and helping flotation

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gravel and coarse sand bottoms are populated overwhelmingly (over 70%) by

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filter feeders

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substrates of fine sand and coarse silt support a mixed faunal assemblage

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detritus, deposit feeders, some infaunal filter feeders and a few epifaunal filter feeders.

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photophores

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light generating organs in deep sea organisms such as lantern fish

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bioluminescence

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created as a byproduct of biochemical reactions in which light is produced by the metabolic activities of symbiotic bacteria that live in dense concentrations within the photophores

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diurnal vertical migration

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lantern fish engage in this. swim upward to photic zone at night to feed and descend to depths between 700 and 900 meters during day

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abyssal depths

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perpetually dark are very cold have high hydrostatic pressure have sparse food supplies

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chemosynthesis

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oxidize hydrogen sulfide to form sulfure compounds

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Law of the Sea

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treaty regulating the exploitation of resources of the continental shelf- made at the 1958 and 1960 Geneva Conventions

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Beginning in 1973,

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The UN organized a third Law of the Sea Conference in NYC to address pressing legal issues

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in 1982, LotS gained support of many

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UN member states and in 1994, signed by the US

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the treaty guarantees

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Territorial seas defined as extending seaward for 12 nautical miles an Exclusive Economic Zone extends offshore for 200 nautical miles or even farther if the edge of the continental shelf lies beyond, legally empowers the coastal state to regulate fishing, mineral resources, pollution and scientific research in these waters Vessels have the right of free and innocent passage in waters outside the territorial seas and through international straits that lie within a territorial sea Private exploitation of mineral resources in the high seas that lie beyond the EEZ in theory requires approval by the ISA

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ISA

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a chartered agency of the UN. mining tech would be shared with this, which is authorized to distribute revenue from resource exploitation of the seabed of the high seas with developing nations

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EEZ

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regulates about 40% of the world's oceans to the control of coastal states. the US has the largest cumulative zone, comprising approx 10 mil km, an ocean area that exceeds its land area by 30%

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Petroleum

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both liquid and natural gas, composed of hydrocarbons. derived from marine sedimentary rocks, notably shales, that contain abundant remains of plankton. less dense than surrounding rock, trapped in sandstones, if temps get very high, oil is converted to methane

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gas hydrates

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have been discovered in the sediment of polar regions and in deposits of continental slopes where cold water is in contact with sea bottom

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methane

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CH4 frozen water molecules that form small cagelike structures in the sediment

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escaping methane is oxidized to bicarbonate

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providing a rich source of food for filter feeders

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manganese nodules

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contain variety of other metals

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cobalt rich crusts

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in EEZ of hawaiian islands, vital for military and industrial enterprises

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phosphate

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forms as an offshore accumulation on submarine terraces where coastal upwelling supports high biological productivity in surface waters, settles on seabed below, buried and transformed into nodules, near morocco, southern california and the carolinas.

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pelagic fish

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inhabit water column

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groundfish

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dwell near or on sea bottom

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mariculture

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farming the seas, raised under favorable conditions to promote growth until they are large enough to be harvested as food

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pollutants tend to be concentrated in

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sea bottom along pycnoclines that separate water masses of diff densities neuston layer

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neuston layer

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interface between air and sea, very thin surface microlayer

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distillation

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hydrocarbon molecules separate crude oils into cuts as crude is heated

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emulsification

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a suspension of liquid in another liquid such as water in oil or oil in water

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spills at sea seem to be less damaging than

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spills near the shore because slicks in open ocean spread out horizontally and vertically

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techniques to contain oil spills

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floating booms, chemical dispersants, burning oil, skim up crude oil

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bioremediation

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stimulating the growth of microorganisms that actively feed on petroleum compounds

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