450
move too quickly through the coastal wetland for significant plant uptake of nitrogen. The remaining nitrogen requirements must then be met by recycling or fixation
from atmosphere.
14.5.1 Soil Nutrient Pools
Reef ecosystems have suffered from a variety of anthropogenic stresses during the
past several decades. Offshore recreational activities, siltation, sewage discharge,
excessive nutrient input, thermal pollution, (Rinkevich 1995a, b) and overfishing
(Luoma 1996) have contributed to the declining health of many reefs. Divers, snorkelers, and boat and cruise ship anchors can physically damage corals by breaking
them, abrading large coral forms, and burying coral fragments in sediment
(Rinkevich 1995). Overfishing of algae-eating fish can lead to accelerated algae
growth that in turn smothers corals (Luoma 1996). Anthropogenic stresses have
contributed to the loss of 10% of the world’s coral reefs and an additional two-thirds
are at risk of serious decline (Luoma 1996). Zoologist Marjorie Reakea-Kudla predicts the loss of 70% of the world’s coral reefs by the year 2036.
Various techniques have been employed to create habitats for reef-dwelling
organisms. In Indian coastal waters, most efforts have focused on increasing fish
populations to provide enhanced experiences for recreational fishing and sportdiving (Hutchings 1996). Activities such as the deliberate sinking of ships or oil
drilling platforms successfully attract fish. However, it is unclear whether these
structures provide suitable habitat for reproduction or just enhance the local population by attracting fish from other areas (Weisburd 1986).
New techniques have begun to focus on the restoration of coral reef ecosystems.
Of all marine ecosystems, coral reefs are the most diverse and complex. The building blocks of the reef are symbiotic animals that rely on specialized algae called
zooxanthelae for nutrients. Through photosynthesis, the algae produce sugars and
starches. In exchange for these products, the corals share a portion of the nitrogen
and phosphorus they obtain by capturing tiny organisms (Luoma 1996a, b). Some
coral species produce calcium carbonate skeletons specially in the region of Gulf of
Mannar, Tamil Nadu. The accumulation of these skeletal structures forms the coral
reef. Each coral species, of which there are hundreds, has its own growth pattern
(Sorokin 1993). Staghorn, elkhorn, and finger coral colonies produce branching
shapes while flower, star, and brain corals produce rounded structures of various
sizes (Greenberg 1986). Coral formations provide the framework for a diverse ecosystem that includes a multitude of fish, crustaceans, invertebrates, and other marine
organisms.
The world’s first, although unintentional, large artificial reefs were sunken ships.
Ships, as well as military tanks (Heins 1995), a retired Boeing 727 (Fritz 1994),
junked automobiles, old toilets (Weisburd 1986), tires and other scrap materials
have been used to construct artificial reefs along the eastern and southeastern coasts
of the United States. The procedures for the construction of these reefs vary
R. Manivanan
move too quickly through the coastal wetland for significant plant uptake of nitrogen. The remaining nitrogen requirements must then be met by recycling or fixation
from atmosphere.
14.5.1 Soil Nutrient Pools
Reef ecosystems have suffered from a variety of anthropogenic stresses during the
past several decades. Offshore recreational activities, siltation, sewage discharge,
excessive nutrient input, thermal pollution, (Rinkevich 1995a, b) and overfishing
(Luoma 1996) have contributed to the declining health of many reefs. Divers, snorkelers, and boat and cruise ship anchors can physically damage corals by breaking
them, abrading large coral forms, and burying coral fragments in sediment
(Rinkevich 1995). Overfishing of algae-eating fish can lead to accelerated algae
growth that in turn smothers corals (Luoma 1996). Anthropogenic stresses have
contributed to the loss of 10% of the world’s coral reefs and an additional two-thirds
are at risk of serious decline (Luoma 1996). Zoologist Marjorie Reakea-Kudla predicts the loss of 70% of the world’s coral reefs by the year 2036.
Various techniques have been employed to create habitats for reef-dwelling
organisms. In Indian coastal waters, most efforts have focused on increasing fish
populations to provide enhanced experiences for recreational fishing and sportdiving (Hutchings 1996). Activities such as the deliberate sinking of ships or oil
drilling platforms successfully attract fish. However, it is unclear whether these
structures provide suitable habitat for reproduction or just enhance the local population by attracting fish from other areas (Weisburd 1986).
New techniques have begun to focus on the restoration of coral reef ecosystems.
Of all marine ecosystems, coral reefs are the most diverse and complex. The building blocks of the reef are symbiotic animals that rely on specialized algae called
zooxanthelae for nutrients. Through photosynthesis, the algae produce sugars and
starches. In exchange for these products, the corals share a portion of the nitrogen
and phosphorus they obtain by capturing tiny organisms (Luoma 1996a, b). Some
coral species produce calcium carbonate skeletons specially in the region of Gulf of
Mannar, Tamil Nadu. The accumulation of these skeletal structures forms the coral
reef. Each coral species, of which there are hundreds, has its own growth pattern
(Sorokin 1993). Staghorn, elkhorn, and finger coral colonies produce branching
shapes while flower, star, and brain corals produce rounded structures of various
sizes (Greenberg 1986). Coral formations provide the framework for a diverse ecosystem that includes a multitude of fish, crustaceans, invertebrates, and other marine
organisms.
The world’s first, although unintentional, large artificial reefs were sunken ships.
Ships, as well as military tanks (Heins 1995), a retired Boeing 727 (Fritz 1994),
junked automobiles, old toilets (Weisburd 1986), tires and other scrap materials
have been used to construct artificial reefs along the eastern and southeastern coasts
of the United States. The procedures for the construction of these reefs vary
R. Manivanan