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that the clear blue water surrounding tropical reefs is depleted of
phytoplankton , which form the base of most marine food webs. The
level of dissolved nutrients in reef waters is low as well which explains
the lack of phytoplankton.
The zooxanthellae are unicellular algae that provide corals with food ,
the zooxanthellae use sunlight , which easily penetrates the transparent
tissue of the coral polyp , to produce food photosynthetically using the
metabolic waste products of the corals as nutrients . As much as 60
percent of this manifactured food passes through cell walls of the
zooxanthellae and nourishes the coral polyp directly.
Ecology of coral reefs :
In the broadest sense , coral can be divided into two major groups :
Hermatypic coral , which possess zooxanthellae, and Ahermatypic
coral , which do not.
Hermatypes build the colonial reefs found in tropical seas.
Ahermatypes , by contrats, tend to be solitary in habit. Unlike the
Hermatypes , the Ahermatypes are not restricted to shallow or warm
water. In fact , they can be found in the deep , dark cold waters of the
polar seas.
Coral do best in water of normal salinity. In fact, they can not survive in
freshwater or even in brackish water. An additional environmental
control on reef development is water turbidity , producing muddy
waters. Suspended sediment particles interfere with the ability of the
zooxanthellae to photosynthesize by decreasing the amount of light that
can be transmitted through the water.
Phytoplankton flourish in tropical seas that contain high concentration
of nutrients . These large phytoplankton populations support dense
benthic communities of filter feeders, which competitively exclude
coral. Thus , hermatypic coral grow in best in warm , clear tropical
water that contains low levels of dissolved nutrients.
Many reefs share general topographic characteristics
that reflect the
degree of exposure to breaking waves. On the windward side , large
pounding waves are absorbed by the Algal ridge , which is continuously
awash with surf surge . Below the Algal ridge is the seaward sloping
that the clear blue water surrounding tropical reefs is depleted of
phytoplankton , which form the base of most marine food webs. The
level of dissolved nutrients in reef waters is low as well which explains
the lack of phytoplankton.
The zooxanthellae are unicellular algae that provide corals with food ,
the zooxanthellae use sunlight , which easily penetrates the transparent
tissue of the coral polyp , to produce food photosynthetically using the
metabolic waste products of the corals as nutrients . As much as 60
percent of this manifactured food passes through cell walls of the
zooxanthellae and nourishes the coral polyp directly.
Ecology of coral reefs :
In the broadest sense , coral can be divided into two major groups :
Hermatypic coral , which possess zooxanthellae, and Ahermatypic
coral , which do not.
Hermatypes build the colonial reefs found in tropical seas.
Ahermatypes , by contrats, tend to be solitary in habit. Unlike the
Hermatypes , the Ahermatypes are not restricted to shallow or warm
water. In fact , they can be found in the deep , dark cold waters of the
polar seas.
Coral do best in water of normal salinity. In fact, they can not survive in
freshwater or even in brackish water. An additional environmental
control on reef development is water turbidity , producing muddy
waters. Suspended sediment particles interfere with the ability of the
zooxanthellae to photosynthesize by decreasing the amount of light that
can be transmitted through the water.
Phytoplankton flourish in tropical seas that contain high concentration
of nutrients . These large phytoplankton populations support dense
benthic communities of filter feeders, which competitively exclude
coral. Thus , hermatypic coral grow in best in warm , clear tropical
water that contains low levels of dissolved nutrients.
Many reefs share general topographic characteristics
that reflect the
degree of exposure to breaking waves. On the windward side , large
pounding waves are absorbed by the Algal ridge , which is continuously
awash with surf surge . Below the Algal ridge is the seaward sloping
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