Capacity of reef countries to adapt to coral reef loss and degradation. Major observed threats to world's coral reefs. Overfishing and destructive fishing. Overfishing schematic. Overfishing. Reef fishing. Herbivore fish overfishing. Shark fishing. Hammerhead caught in gill- Source WWF. Coral reef fishing and coral-algal phase shifts: implications for global reef status - 572.full.pdf. Coral Reef Loss: Determining the Importance of Overfishing and Nutrient Pollution in the Global Decline of Coral Reefs. Coral reef ecosystems are among the most diverse and highly productive ecosystems on the planet yet are currently threatened by a number of natural and human-induced factors.
Regardless of the cause, reef degradation generally results in an irreversible phase-shift from dominance by reef-building corals to dominance by fleshy macroalgae or seaweed. These shifts are believed to be irreversible and lead to communities that are less diverse and much less complex. While a number of natural disturbances can cause localized coral mortality, reduced top-down control (caused by overfishing) and increased bottom-up control (caused by nutrient pollution) are the most frequently implicated causes of human-induced reef degradation (aside from global warming). The relative importance of each of these factors in causing reef decline has been the subject of debate and much research among scientists.
Background Information environments around the Hawaiian Islands. Project Page. Human Impact on the Great Barrier Reef: Over-fishing. OverfishingReefs are suffering directly and indirectly from the increasing pressure of mans' resource exploitation (Reef Education Network).
Overfishing is one driving pressure that has had devastating impacts on coral reefs. Aggressive fishing methods have hurt coral reefs sometimes beyond repair. However, over-fishing in general is also a damaging problem to many coral reefs around the world. Specifically to the Great Barrier Reef, overfishing has caused a shift in the reef ecosystem. Coral Reefs: Past, Present and Future. "Anthropogenic" Disturbances Overfishing How do we know this (see Jackson et al. 2001)?
Similar patterns are true of other coastal ecosystems such as estuaries (Florida Bay) and kelp beds: Overfishing of herbivorous fish interacts with the effects of eutrophication to affect the community structure of coral reefs. Jamaica is a classic example of a phase shift from a coral reef dominated community to a macroalgal community. Selective overfishing of populations, for example spawning aggregations, can have particularly disastrous effects. For example: one (1) 61cm female snapper produces the same number of eggs as two hundred and twelve (212) 41cm female snappers.
Or: 12.5kg of large snapper has the reproductive potential of 233kg of small snapper. Destructive fishing Destructive fishing practices can destroy reef communities very effectively in a very short span of time. Related Writings. The Effects of Overfishing on Marine Biodiversity by Mercedes Lee and Carl Safina Originally published in Current: The Journal of Marine Education, 13: 5-9, 1995.
"The last fallen mahogany would lie perceptibly on the landscape, and the last black rhino would be obvious in its loneliness, but a marine species may disappear beneath the waves unobserved and the sea would seem to roll on the same as always. " (Ray, p. 45) Overfishing occurs when fish are being caught faster than they can reproduce and replace themselves. In the face of environmental change, the loss of genetic diversity weakens a population's ability to adapt; the loss of species diversity weakens a community’s ability to adapt; the loss of functional diversity weakens an ecosystem's ability to adapt; and the loss of ecological diversity weakens the whole biosphere’s ability to adapt.
Blast and fish poisoning. Dynamite fishing. Coral disease. Global Coral Disease Database: Main. Global Coral Disease Database: Main. Global Coral Disease Database: Experts. Coral disease in the Caribbean. Coral Reefs: Past, Present and Future. Diseases White band disease.
Coastal development threats. Other threats from tourism. Avoid trampling on reefs! Coral Reefs: Past, Present and Future. Climate change impacts on coastal Communities - GBRMPA. Climate change has consequences for coastal Great Barrier Reef communities through impacts on key industries.
There are also likely to be other effects on coastal development and human health, for example changes in water quality. Impacts Individuals, communities, and industries in the Great Barrier Reef catchment depend directly or indirectly on the Great Barrier Reef ecosystem for goods and services. These take the form of direct economic benefits (including commercial activities such as tourism and fishing), social services (including recreational activities and cultural linkages) and environmental services (including shoreline protection from barrier reefs and mangrove stands).
Human health and coastal development are other ways in which the Great Barrier Reef social system is vulnerable to climate change. Outlook Climate change is likely to place coastal development at risk, primarily due to predicted sea level rises. Impacts of Climate Change. Microdocs: Acid Ocean. Ocean acidification - Hermie the hermit crab. Microdocs: Swept Away by Global Warming. Coral bleaching observations. Coral bleaching on the Great Barrier Reef. Coral Bleaching.