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 global warming and ocean acidification are the greatest, and they’re accelerating the decline of corals around the world. The year 2009 marked the warmest ocean temperatures ever recorded, putting corals at risk and foreshadowing what we can expect as climate change continues. Urgent action is needed to save the world’s coral reefs from extinction.
That’s why the Center has expanded our efforts to conserve coral reefs. Our coral work began — and is ongoing — with defending elkhorn and staghorn corals, for which we earned federal protection for in 2006. In 2009 we filed a scientific petition to protect the 83 most vulnerable corals within U.S. waters — the corals that can benefit most from U.S. protection — as threatened or endangered under the Endangered Species Act. Under pressure from the Center, the National Marine Fisheries Service released a status review of the 82 corals, finding that 56 of them are likely to go extinct before the end of the century primarily because of ocean warming, disease and ocean acidification.
In 2012, 66 corals saw victory when — after the Center filed three notices of intent to sue the Fisheries Service if it continued to ignore our petition — in December the agency proposed 12 coral species for protection as "endangered" and 54 species for protection as "threatened."
THREATS TO VANISHING CORALS
The declines of the petitioned-for corals 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 to coral reefs is carbon dioxide emissions from burning fossil fuels. The world’s leading coral biologist, Charles Veron, warns us that unless CO2 concentrations in the atmosphere are reduced to below 350 parts per million soon, coral reefs and reef-dependent marine life will be committed to a terminal and irreversible decline due to global warming and ocean acidification.
In recent years global warming has caused nearly every reef around the world to suffer declines. When corals are exposed to elevated ocean temperatures they are susceptible to bleaching — which means that they expel the colorful zooxanthellae algae they need to survive — and 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 protective 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 coral reefs and coral ecosystems.
CASE STUDIES: CORALS AT RISK
The Center seeks protection for all corals in U.S. waters for which population declines have been estimated at more than 30 percent in 30 years. These include eight corals species in Florida and the Caribbean, eight corals in Hawaii, and 67 corals occurring in American territories of the Pacific. Here’s an introduction to just a few of the coral species our petition advocates for:
Mountainous star coral (Montastraea faveolata)
Once considered the dominant reef building coral of the Atlantic, more than half of these corals have disappeared in just three decades. This Caribbean coral is susceptible to bleaching, ocean acidification, pollution, and disease. Already, the decline and death of this coral is outpacing its ability to grow and build new colonies.
Ivory tree coral (Oculina varicosa)
This Caribbean coral is a slow growing and delicate branching coral whose thickets provide a home to various reef fish. Ivory tree coral is considered a keystone species, meaning that its own health indicates the health of the ecosystem around it – thus, it’s telling that these corals have been decimated by destructive fishing practices such as bottom trawling which has killed about 30 percent of the population across its range.
Blue rice coral (Montipora flabellata)
Only found in Hawaii, blue rice coral is uncommon and thrives in shallow reefs pounded by waves. Although this coral is usually flat and sheetlike, on one reef in Molokai it grows branches with an opening at the tip that provides a home to small shrimp. Blue rice coral is vulnerable to bleaching, habitat degradation, and disease.
Hawaiian reef coral (Montipora dilatata)
Hawaiian reef coral remains in fewer than five locations. It has the unfortunate trait of being among the first corals to bleach during increased water temperatures, and the slowest to recover. It has experienced significant climate-related population fluctuations over the last 20 years, and its small distribution makes it extremely vulnerable to extinction. Hawaiian reef coral has been considered a species of concern by the National Marine Fisheries Service since 2004.
Flowerpot coral (Alveopora allingi)
As its common name suggests, flowerpot coral resembles a bouquet of flowers. Overexploited by the aquarium trade and rapidly losing habitat, this coral is found in American Samoa, the Northern Mariana Islands, Palau, and other areas of the Pacific. Flowerpot coral has the highest bleaching response of any coral genus, making it extremely vulnerable to global warming.
Acropora corals are the most abundant corals on the majority of the reefs in the Indo-Pacific. However, these corals are extremely sensitive to bleaching and disease, and they’re slow to recover. Our petition seeks to protect several Acropora corals found in Hawaii and the greater Pacific. Two Acropora species in the Caribbean — elkhorn and staghorn corals — are already protected as threatened under the Endangered Species Act as a result of a petition filed by the Center.