The world's corals and coral reef ecosystems are in crisis. In just a few decades, scientists warn, these “rainforests of the sea” and all their rich biodiversity could disappear completely. While corals face numerous dangers, the overarching threats of climate change and ocean acidification are the greatest, and they're accelerating the decline of corals around the world.
The Center’s coral work began with our 2004 petition defending elkhorn and staghorn corals, which earned them federal protection in 2006: the first two species listed under the Endangered Species Act because of vulnerability to global warming. After we sued, both corals also won almost 3,000 square miles of federally protected critical habitat.
In 2009 we petitioned to protect the 83 most vulnerable corals. Under pressure from the Center, NOAA Fisheries released a status review of those corals, finding that 56 of them will probably go extinct before the century’s end, primarily because of ocean warming, disease, and ocean acidification. In 2014, after three notices of intent to sue, NOAA Fisheries finally protected 20 corals as threatened.
We petitioned and sued in our campaign to protect the cauliflower coral, Pocillopora meandrina, in Hawaii, which has seen a 36 percent drop in coverage around the Hawaiian Islands in recent years.
THREATS TO VANISHING CORALS
The declines of the corals we defend have been linked to numerous major threats, including destructive fishing practices, overharvest, disease, predation, pollution and physical damage from boats. But the greatest threat of all threats to coral reefs is carbon dioxide emissions from burning fossil fuels, which leads to ocean warming and acidification. Leading coral biologist Charles Veron has warned that unless CO2 concentrations in the atmosphere are reduced to below 350 parts per million soon, all coral reefs and reef-dependent marine life will suffer a terminal and irreversible decline due to global warming and ocean acidification.
In recent years global warming has harmed almost every reef around the world. When corals are exposed to elevated ocean temperatures, they’re susceptible to coral bleaching — which means they expel the colorful zooxanthellae algae they need to survive. While some corals may survive a bleaching event, many will die. This risk is growing ever more dangerous because global warming increases the severity, length, and frequency of bleaching events.
The more CO2 we spew into the air, the greater the consequences of bleaching will be for coral reefs. Corals face another ominous threat from the oceans becoming more acidic as they absorb CO2 from the atmosphere, and this means that corals will have difficulty growing and building their skeletons as ocean waters become more corrosive. Thus corals that suffer from bleaching may never be able to rebuild their majestic reefs.
If corals are to survive, they need relief from each of these threats, and the strong protections of the Endangered Species Act will be a vital step toward the conservation of corals and coral reef ecosystems.