Deep-sea corals are perhaps the most vulnerable to bottom trawling of all forms of marine life.
corals, found off all coasts of North America, are the ancient forests
of the oceans. These beautiful living colonies are extremely
slow-growing - less than an inch a year - and some may be thousands of
years old. The corals are spawning and nursery grounds for many
commercial fish and other marine life, and provide young fish with
shelter from predators.
The destructive bottom trawling gear used in many commercial fisheries is the most widespread human threat to deep-sea corals. A simple examination of common bottom trawling gear reveals its destructive potential. Trawl nets, which may stretch 40 feet or more in height and spread over 200 feet wide, are dragged between heavy trawl doors weighing as much as five tons each, bulldozing across the sea floor. Trawls capture virtually everything in their path, including targeted and untargeted fish, marine mammals, turtles, sponges, and deep-sea corals.
With the advent of ever more powerful engines, mapping, navigational and fish finding electronics, and stronger, lighter synthetic materials, bottom trawlers can now operate to depths of 6,000 feet. Using coral-crushing roller and rockhopper gear on their nets, trawlers can fish in deep-sea canyons and over rough seafloor, once avoided because of the damage they caused to nets. Some 40 percent of the world's trawling grounds are now deeper than the edge of the continental shelf and are on the slopes and in the canyons of the continental margins and on seamounts, where most of the world's known deep-sea coral communities are found.
A recent study by the National Academy of Sciences found that over the past decade, more than 231,000 square miles of seafloor off the US coast - roughly the size of California - has been directly affected by bottom trawling. The National Marine Fisheries Service estimates that in Alaskan waters alone, more than a million pounds of corals and sponges are removed from the seafloor every year by commercial fishing, roughly 90 percent by bottom trawlers. That figure may grossly underestimate the actual level of damage. Many of the corals and sponges are crushed and not pulled to the surface and counted by observers, and scientists are only beginning to document how widespread deep-sea corals are.
Unfortunately, many of the deep-sea coral communities of the world have already been destroyed by bottom trawling, some probably forever. But many deep-sea coral communities remain, and new ones are still being discovered. Several steps need to be taken to protect these communities, which are invaluable to the ocean ecosystem.
First, we need to map all locations of coral communities. During this process, the federal government should prohibit the expansion of trawling and close currently trawled areas with known concentrations of corals and sponges. Trawling gear should be modified or banned so that trawling in coral areas is no longer mechanically possible. In addition, the federal government should enhance enforcement and establish severe penalties to prevent deliberate destruction of corals and to prevent illegal fishing in already closed areas. Finally, the government should fund research to restore damaged deep-sea coral communities.
Deep-sea corals, so vital to marine ecosystems, are perhaps the most vulnerable to bottom trawling of all forms of marine life. We've seen what happened to our ancient forests. We can't let that happen to our coral forests, especially when we have the power to protect them for the good of future generations.
Ted Danson is on the Board of Directors of Oceana, a non-profit organization dedicated to restoring and protecting the world's oceans through policy advocacy, science, law and public education. Founded in 2001, Oceana includes members and activists from more than 150 countries and territories who are committed to saving the world's marine environment. For more information, please visit www.oceana.org.