Around the globe, coral reefs and the colonies of marine life they support are in crisis mode, suffering from what may be irreparable damage to their delicate ecosystems.
Many factors are contributing to the vulnerability of corals and coral reefs:
- Overharvest of marine life and corals
- Land-borne pollution such as fertilizer runoff from rain water or irrigation
- Debris and reckless dumping that can damage or become entwined in coral formations, destroying formations and trapping other marine life that makes its home in the reef
- Ocean acidification
- Pollution and physical damage from boats, including propellers and anchors
- Careless or irresponsible actions by divers
- Destructive fishing practices
But the greatest threat to coral reefs is the rising content of carbon dioxide generated by climate change and the global impact of burning fossil fuels. Rising ocean temperatures result in coral bleaching.
While some corals are able to tolerate the effects of bleaching, many are not, and are likely to face extinction without immediate action to reduce the impact of climate change.
What is Coral Bleaching?
Coral bleaching is a condition where corals are impacted by rising ocean temperatures, expelling the zooxanthellae algae that they depend on for survival. Some types of corals may be able to tolerate a bleaching event – at least for the short term – but many types of coral cannot, and will die off.
Zooxanthellae are small organisms that dwell within some land animal tissues, as well as in marine life such as corals and anemones. These algae absorb sunlight and transform it into energy in the same way as plants, providing corals with essential nutrients for their survival. Higher temperatures can either kill off the organisms, or drive them to leave the corals for other hosts that are more suitable.
These nutrients are also what provides corals with the beautiful vivid colors. Without the algae, the coral reverts to a white skeleton or bleached appearance.
Loss of these critical nutrients by the corals is appropriately known as bleaching, and can quickly result in their demise.
Where is Coral Bleaching Having an Impact?
Coral bleaching is not isolated to any particular region – or even a specific ocean. This is a world-wide dilemma that requires the attention of citizens and governments across the globe.
Perhaps the best-known of all coral reefs is the Great Barrier Reef of Australia. Environmentalists note that the reef has declined in its coral cover by nearly 50% just in the last 27 years. Aerial surveys by researchers such as the ARC Center of Excellence reveal severe bleaching that has occurred in the reef for two consecutive years.
Oceans of Southeast Asia are home to nearly 34% of the world’s coral reefs. The reefs of this region are similarly threatened by mankind’s activities.
Reefs throughout the world are subject to the threat of pollution and climate change that results in coral bleaching, including:
- Papua New Guinea
- Solomon Islands
Incredibly, the World Resources Institute estimates that only 12% of the world’s coral reefs are considered to be at low risk.
What is Being Done About Coral Bleaching?
Coral conservationists have gone to great lengths to focus the attention of the public and governing agencies on the severity of climate change and its impact on coral reefs and reef-dependent life forms, with some success:
The Center for Biological Diversity has worked in earnest to protect coral reefs that they refer to as the “rainforests of the sea”. The center has successfully petitioned the National Marine Fisheries Service to declare some coral species as threatened, including reefs in the Caribbean and Indo-Pacific oceans.
U.S. involvement and the protection of world-wide corals under the Endangered Species Act is a major step forward in the future of these delicate ecosystems. The center’s petition seeks protection for many types of coral, especially those that succumb more readily to the effects of coral bleaching, and may take longer to recover – if they recover at all.
The Nature Conservancy proposes many ways that average citizens can aid in the fight to protect coral reefs, among them:
- Use lawn care products responsibly. Even chemicals applied hundreds of miles from the sea may combine with other runoff that eventually finds its way into the ocean, polluting and harming coral reefs and other sea life.
- Support businesses that practice marine conservation. Patronize those hotels, fishing excursions, dive operators, and vacation spots that demonstrate concern for the environment and reef life.
- Let your representatives know of your concerns, promoting legislation that secures the future of our beautiful coral reefs.
Coral reefs do much more for the environment that providing natural beauty and a natural habitat for many species of marine life. Reefs serve as natural breakwaters for coastal and island areas, reducing the impact of waves by as much as 97%, per recent studies.
Practicing conservation as individuals and working together to reverse climate change are critical for the preservation of our world-wide corals and understanding the importance of retaining these resources for a wide variety of marine life for future generations.