LOS ANGELES, Aug. 26 (UPI) -- An analysis of hundreds of coral reefs worldwide indicates human activities are having a profound negative impact on the health of these delicate ecosystems, researchers reported Monday.
Reef Check, a 5-year study of the planet's coral reefs and the threats to them, deployed more than 750 volunteer sport divers, trained and led by 100 scientists in surveys of more than 300 reefs in the Atlantic, Caribbean and Indo-Pacific regions offshore 31 countries. In all, about 5,000 people participated in the study, the results of which are compiled in the report "The Global Coral Reef Crisis: Trends and Solutions."
Gregor Hodgson, director of Reef Check and a visiting professor at the Institute of the Environment at the University of California at Los Angeles, told United Press International, "We've stuck our neck out and said that these indicators are human impact indicators on reefs ... This is defining the issue objectively for the first time."
Reef Check's investigators found many signs the health of coral systems is in decline. Globally, for instance, there were no spiny lobsters found at 83 percent of shallow reefs, indicating overfishing. Spiny lobsters are a "universally prized seafood item," the report said, but 90 percent of the reefs in the Indian and Pacific oceans had no lobsters, while 49 percent of those in the Atlantic had none.
In addition, "The mean abundance of Diadema sea urchins decreased significantly in the Indo-Pacific from 1998 to 2000, approaching levels similar to those found in the Atlantic and possibly indicating ecological destabilization," the report said.
Virtually every indicator examined by the study showed some reason for concern. There were no moray eels on 81 percent of the reefs. Four species of fish -- Nassau grouper, barramundi cod, bumphead parrotfish and humphead wrasse -- are in critical condition, missing from nearly 90 percent of the reefs. Mean hard coral cover was only 32 percent of expected levels. A 1997-98 bleaching event "reduced live coral cover by 10 percent globally, indicating that coral reefs are a sensitive indicator of global warming," the report said.
Reef Check rated the impact of humans on coral reefs and found it was higher in the Atlantic than in the Indo-Pacific. In particular, diving and sewage disposal are having a more dramatic impact in the Atlantic than in the eastern hemisphere. In the Pacific, however, fishing with dynamite and poisons is a much more serious problem than in the Atlantic. Human impacts to reefs from overfishing, harvest of invertebrates and aquarium trade are similar in both hemispheres.
The report shows, however, that Marine Protected Areas in developing countries is having some success. "Five of ten fish and one of ten invertebrate indicators were significantly more abundant inside than outside MPAs." the report said.
"The other good news," Reef Check's Hodgson said, "is that the living coral cover has recovered nicely since 1998."
Attention to the health of offshore ecosystems is relatively recent. The first major scientific meeting on coral reefs was not held until 1993. The Reef Check effort grew out of that meeting.
Hodgson said although Reef Check can assess the current state of coral reefs, it is harder to know where management of the reefs should lead, because there is little baseline data from earlier times. "You cannot find a giant clam on a reef anywhere that is larger than 30 centimeters," he said. "The big organisms are gone. The big groupers, the big fish are gone."
Heidi Schuttenberg, an environmental policy specialist on the coral team at the National Oceanic and Atmospheric Administration, told UPI, "The Reef Check report is really important because it covers a large area and allows you to make comparisons you can't make other ways."
David Kennedy, director of NOAA's office of response and restoration, also told UPI it has been difficult to obtain baseline data from which to measure the improvement or decline of coral reef health.
"We know that coral is still in decline," Kennedy said. "We are still in the early phases of feeling that we have a complete characterization of corals in the United States."
NOAA's Kennedy said his agency's research indicates "global warming maps (reef effects) closely ... When there are significant changes in temperature over coral, significant things happen, one of which is bleaching. You can tie bleaching events to warming events."
Most of the world's coral reefs are found in developing countries, the report noted, where human populations have doubled over the last 20 years. As fishing technologies have improved, fishermen who once stuck close to shore now have expanded into other areas, often with "perverse subsidies" from governments.
"The world's fishing industry spends $124 billion every year to produce $70 billion worth of fish," the report said. "The difference ($54 billion) is paid for in subsidies."
NOAA's Kennedy said a recent economic assessment indicates in Hawaii alone, coral reefs are worth more than $10 billion to the local economy.
Hodgson said 350 million people depend directly on coral reef ecosystems for food. In addition, a number of products important in the developed world -- such as the AIDS drug AZT -- have been extracted from coral reef organisms.
(Reported by Dan Whipple, UPI Science News, in Broomfield, Colo.)