[Home]   [Full version]  

First Coral Species Listed as Threatened

May 24 ,General Science



Full size image
Coral reefs, the most productive and diverse marine ecosystems in the world, are based on the coral organisms that build reefs. Drastic coral declines in the last 25 years have resulted in the listing of two species, staghorn and elkhorn corals, as threatened under the U.S. Endangered Species Act (ESA).

The National Oceanographic and Atmospheric Agency (NOAA) Fisheries Service registered elkhorn (Acropora palmata) and staghorn corals (Acropora cervicornis) as threatened on May 9, 2006, with official listing effective 30 days after. This is the first time a coral has been listed as endangered or threatened under the ESA, focusing attention on the global degradation of coral reefs.

“The decline of elkhorn and staghorn corals is likely the symptom of a problem that is impacting coral reefs around the world – that problem is global warming,” said John Rollino, senior ecologist at Earth Tech, Inc. and principal investigator of Earthwatch’s Bahamian Reef Survey project. “In 2005, huge portions of the reefs in the eastern Caribbean have undergone drastic declines due to coral mortality from above average water temperatures. Some of the individual coral colonies that perished last year were alive over a hundred years ago.”

Elkhorn and staghorn corals are in the genus Acropora, the most abundant group of corals in the world and once the most important reef-building species throughout the Caribbean. Their familiar branching shapes, and relatively high growth rates for corals, offer essential habitat for fish and other reef animals that no other coral species provide. Both species have declined an estimated 90 to 98 percent since 1980.

“The loss of Acropora corals could be the first step in an unraveling coral reef ecosystem,” said Dr. Daniela Maldini, director of research at Earthwatch Institute. “Earthwatch is supporting crucially important coral reef research projects around the world to monitor this coral crisis in an effort to find solutions.”

For the last 14 years, Earthwatch teams working with scientists Tom McGrath and Dr. Garriet W. Smith, and more recently with Rollino, Smith, and colleagues, have collected data on coral decline on San Salvador, Bahamas. Elkhorn coral and staghorn coral were common at the start, forming massive, dense thickets and branching structures that provided cover for a diversity of reef fish. In recent years, however, elkhorn and staghorn corals have become practically absent from San Salvador’s reefs.

Last year witnessed a severe coral bleaching event in the Caribbean, yet another blow to Acropora populations in the region. Coral bleaching occurs when environmental stresses, like temperature change, cause symbiotic algae to be expelled from the coral polyps in which they live. If bleaching continues for an extended period, the corals will die, but bleaching is just one of the symptoms of environmental impacts on corals.

“The overwhelming majority of the decline of elkhorn and staghorn corals on San Salvador was by disease, most notably white band disease, coupled with the 1998 mass bleaching event,” said Rollino. “Regionally, their decline has resulted from several perturbations, including global warming, increased sedimentation and degraded water quality, disease, increased storm activity and damage, and/or vessel and tourism damage.”

Rollino recognizes that many of the reasons for coral decline are identified as “unmanageable” under the ESA. However, the listing will require heightened awareness and regulations for any actions that may affect corals in the U.S, from coastal development to sewage outfall. Most importantly, the ESA listing will increase public awareness of the problem and inspire public action.

“I encourage people to learn how inter-connected many of our environments are, and realize that local problems and actions may affect environments far away,” said Rollino.

He urges the public to critically review Environmental Assessments (EAs) and Environmental Impact Statements (EISs) for projects that may impact coral habitats in their region. “As someone who has authored countless EAs and EISs, I encourage people to read these documents and comment.”

Finally, Rollino urges people who see staghorn or elkhorn corals to document the location and report it immediately to NOAA and local conservation agencies. An important step in the recovery of these species will be the identification of remaining populations.

Source: Earthwatch Institute

Related stories:

A third of reef-building corals face extinction
A third of reef-building corals around the world are threatened with extinction, according to the first-ever comprehensive global assessment to determine their conservation status. The study findings were published today by Science Express.
NOAA report states half of US coral reefs in 'poor' or 'fair' condition
Nearly half of U.S. coral reef ecosystems are considered to be in "poor" or "fair" condition according to a new NOAA analysis of the health of coral reefs under US jurisdiction. The NOAA report says that the nation's coral reef ecosystems, particularly those adjacent to populated areas, continue to face intense human-derived threats and while remote reefs are subject to threats such as marine debris, illegal fishing and climate change.
8-day undersea mission begins experiment to improve coral reef restoration
Scientists have begun an eight-day mission, in which they are living and working at 60 feet below the sea surface, to determine why some species of coral colonies survive transplanting after a disturbance, such as a storm, while other colonies die.
Group threatens to sue U.S. over corals
An environmental group is threatening to sue the U.S. government for failing to draw up a plan to protect two coral species newly listed as endangered.
Staghorn and elkhorn corals now protected
Caribbean elkhorn and staghorn corals Thursday were placed under the protection of the U.S. Endangered Species Act.
Two more corals become threatened species
Two types of corals have been declared threatened under the U.S. Endangered Species Act -- reportedly the first time coral has been placed on that list.
Satellites collect data on sea temperatures, reefs
(AP) -- Satellites are helping scientists expand a virtual network to watch for increases in ocean temperatures that can damage or kill the fragile ecosystems of coral reefs worldwide.
Diversity of plant-eating fishes may be key to recovery of coral reefs
For endangered coral reefs, not all plant-eating fish are created equal. A report scheduled to be published this week in the early edition of the journal Proceedings of the National Academy of Sciences suggests that maintaining the proper balance of herbivorous fishes may be critical to restoring coral reefs, which are declining dramatically worldwide. The conclusion results from a long-term study that found significant recovery in sections of coral reefs on which fish of two complementary species were caged.

News discussion:

General Science news

[Home]   [Full version]