Nearly a decade after the launch of several international initiatives to raise awareness about the declining health of the world's coral reefs, these "rainforests of the sea" remain in a desperate struggle for survival, with most dying off in ever greater expanses and only a few reef systems showing evidence of modest recovery.
The ongoing destruction, documented by scientists in recent surveys, is largely the result of human activities, including overfishing, pollution and sediment runoff due to deforestation, the researchers say. If current trends continue, they warn, the vast majority of these valuable ecosystems -- many of which have been growing for hundreds or thousands of years -- are likely to disappear within the next few decades.
At the same time, researchers are discovering entirely new kinds of coral communities, including some that live at tremendous depths, far from the sunlight and warm waters commonly associated with coral reefs.
But these "deep sea coral" communities, too, are being damaged and destroyed at alarming rates, scientists say. Here the culprits are "rock-hopping" nets and other bottom-trawling equipment dragged by powerful fishing ships as they probe farther and deeper from the industry's traditional, depleted haunts in search of shrimp, cod, flounder and rockfish.
The news that tropical corals are continuing to suffer despite conservation efforts -- and the emerging recognition that cold-water corals are being ruined almost as quickly as they're being discovered -- has led to a new round of efforts to preserve these colorful, biodiverse communities.
Coral reefs occupy less than 1 percent of Earth's surface but are home to about one-quarter of all marine fish species. The case for conservation is economic as well as ecological: As major magnets for tourism and other recreational activities, coral reefs bring income to coastal communities -- including many in developing nations that have few other resources to bank on. And reefs provide food and breeding grounds for one-tenth of all the fish caught for human consumption.
If there is one bit of promising news for corals it's in the Caribbean, where the massive declines documented in the 1980s appear to have slowed or in some cases even reversed themselves in the 1990s, according to a report by British scientists published in last week's issue of the journal Science.
"In places like Jamaica, the Virgin Islands, Puerto Rico and Florida, the decline has nearly stopped," said Isabelle Cote, a tropical marine ecologist, who conducted the analysis with Toby Gardner and colleagues at the University of East Anglia in Norwich.
It is too soon to say whether those improvements can be credited to the past decade's conservation efforts, including the creation of protected areas and fishing restrictions in the region. (Some Caribbean coral losses had been traced to overly large catches of algae-eating fish, allowing the algae to choke the slower-growing coral species.)
But with the new survey providing the most quantitative assessment yet of coral cover in the region, it should now be possible for policymakers to track more precisely the impact of their conservation efforts and, over time, tailor their actions for the greatest effect, Cote said.
Meanwhile, Cote said, there is no time for complacency. The 1990s saw continuing losses of coral cover in other regions of the Caribbean, including the Netherlands Antilles and regions off the South American coast. And even where reefs appear to be recovering, the nature of those recoveries has some researchers worried. The hard corals that once thrived there are in many cases being replaced by "opportunistic" coral species that are quick to move in when space becomes available but which, scientists suspect, are less likely to survive shifting temperatures, storms and rising sea levels.
In the Pacific, where coral losses have been caused mostly by overfishing (including the use of reef-killing dynamite and cyanide) and a "bleaching" disease linked to global warming, the situation is "gloomy," said Ove Hoegh-Guldberg of the University of Queensland in Australia.
Indeed, a new report on 14 major tropical reef systems, including some in the Pacific, Atlantic, Red Sea and off Australia, also published in last week's Science, concludes that "reefs will not survive without immediate protection from human exploitation" across wide swaths of ocean.
The same may be true for cold-water reefs, said Michael Hirshfield, chief scientist for Oceana, a Washington-based oceans advocacy group that released a report on those reefs last month. "Trawlers today are fishing down a mile or more," he said. "The slopes and shelves off the continental margins are really being hammered."
Scientists are just beginning to learn about these deep-sea counterparts to the better-known tropical corals. While shallow-water corals live in symbiotic communion with algae that give the corals energy through photosynthesis, deep-sea corals live in darkness and consume organic matter settling to the sea bottom. They exist in waters as cold as 30 degrees Fahrenheit, from the equator to the Arctic, in some cases forming spectacular stony mounds that can tower hundreds of feet above the ocean bottom.
Congress is starting to take note of these mysterious marine creatures. Rep. Joel Hefley (R-Colo.) recently introduced the Ocean Habitat Protection Act, which would place size limits on ground-fishing gear that damages deep coral reefs and other seafloor life. A similar bill is being drafted in the Senate.
Environmental activists say they will petition the secretary of Commerce this month to declare deep-sea coral beds "habitats of particular concern." That would replace the current patchwork of state and regional restrictions on deep-sea coral-reef fishing with uniform federal restrictions.
"I grew up dreaming about space exploration and the search for life on other planets," said Hirshfield of Oceana, which is spearheading the petition. "Well, this is a largely unknown world right on our own planet, with life forms we're just beginning to understand, and it would be tragic if we destroyed it before we even knew the names of the things we're looking at."
© 2003 The Washington Post Company