Fish vanishing from Hawaii's coral reefs
Sharks and jacks, parrot fish and other colorful reef fish are quickly disappearing from coral reefs encircling the Hawaiian Islands, leaving three-quarters of reef fish in a dire state, federal scientists reported today.
The scientists blamed overfishing for the steep decline in dozens of species of fish once commonly found on coral reefs, delighting snorkeling tourists and feeding subsistence fishermen who live in coastal communities.
Many of these fish, ecologists say, are key to maintaining healthy coral reefs because they keep reefs clean by grazing algae that can quickly overgrow the stony corals and result in their collapse.
Alan Friedlander, a federal fisheries ecologist, said Hawaii still has relatively healthy reefs. "So everything hasn't collapsed yet," he said. "But we need to protect healthy reefs, because it's so much easier and safer to conserve now than it is to try to rebuild later."
The results of the study, the most comprehensive examination of of Hawaiian reef fish, was released at the International Coral Reef Symposium in Fort Lauderdale, Fla. Nearly 3,000 scientists, managers and conservationists have congregated here to pore over the latest science and wrestle with ways to protect the world's coral reefs, which continue a steep decline.
Many prominent scientists believe that overfishing represents one of greatest challenges to maintaining and restoring healthy coral reefs.
Daniel Pauly, director of the University of British Columbia's Fisheries Centre, pointed out today that international authorities and local governments on Pacific island nations have little understanding of how many fish are being removed from coral reefs by small-scale, subsistence fishermen.
For the most part, catch data compiled by American Samoa and other such island nations, do not incorporate all of the small-boat fishermen who paddle or motor out to catch fish for themselves and their families. Comparing census data of per-person fish consumption and other sources, Pauly and his team of researchers discovered that in some cases the unreported catches were 17 times as high as reported catches. On average, they were at least twice as high.
Reconstructing a clearer picture of historic catches, Dirk Zeller and Jennifer Jacquet at the Fisheries Centre found that domestic caches have declined between 54% and 86% since the 1950s.
This finding is important, Pauly said, because such fish catch data help determine if countries should sell fishing right to foreign fishing fleets. If the local reliance on fish is underestimated, such deals to bring in foreign fishing trawlers and long-liners can come at the expense of an important local source of protein.
"Coral reef fisheries," Pauly said, are "very important because they are supporting millions of people in the developing world." He said that countries and the United Nations' Food and Agriculture Organization need to pay attention to these unreported catches to assure the food security of these isolated islands struggling with the cost of imported food that is spiraling higher with fuel costs.
The study also found that Hawaii's unreported recreational fisheries for reef fish and deep-dwelling bottom fish was equivalent to the total commercial catch, meaning that twice as many fish were caught as reported.
"Overfishing is often disputed in Hawaii and elsewhere because catch data is underreported or spotty," Friedlander said.
The study conducted by Friedlander and his colleagues from the Oceanic Institute and the National Oceanic and Atmospheric Administration's Biogeography Branch on Oahu got around this problem by diving into the water and meticulously counting fish.
Teams of divers looked at 55 species of fish found on coral reefs around the main Hawaiian Islands as well as the remote and largely un-fished northwestern Hawaiian islands, which lie hundreds of miles farther north and west of Kauai.
Comparing the fish count at both places, the divers determined that 75% of the species around the main islands, such as Oahu, Maui and the Big Island, were in critical condition or depleted. Another 11% were below desirable levels.
Friedlander said Hawaii would be well served by tightening fishing regulations. He also said it would be beneficial to set aside protected no-fishing reserves to conserve coral reefs, helping to ensure that reef fish don't disappear for future generations.
"Probably in Hawaii, more than anywhere else in the United States, people rely on fish to feed themselves and their families," Friedlander said.
-- Kenneth R. Weiss
Photo by David Olsen/Photo Resource Hawaii