North of the Aleutian Islands, canyons in the cold waters of the eastern Bering Sea contain a “green belt” that is home to many deep-water corals as well as many fish and marine mammals.
The area also supports a thriving bottom-trawling fishing industry that uses large weighted nets dragged across the seafloor to scoop up everything in their path.
A new study has identified coral and sponge habitats in the Bering Sea that are likely threatened by bottom-trawling and shows how restrictions on trawling in canyons would affect the fishing industry.
“There’s a growing awareness of deep-water corals and their importance as fish habitat as well as their vulnerability to bottom trawling,” says research biologist Robert Miller of University of California, Santa Barbara’s Marine Science Institute. “They take a long time—tens to hundreds of years—to recover from being destroyed by bottom trawlers, particularly the big specimens, which can be really old.”
The results appear in the journal Global Ecology and Conservation.
Larger than the Grand Canyon
The team, which included colleagues from Greenpeace, based their findings on by catch records, National Oceanic and Atmospheric Administration (NOAA) surveys, and submersible expeditions. They also analyzed data such as temperature, bottom slope, and current speed to identify the best locations for coral and sponge habitat in the Bering Sea.
They found that Pribilof Canyon—an area larger than the Grand Canyon—contains the area’s densest populations of deep-sea corals and sponges.
One of five major canyons carved into the Bering Sea slope, Pribilof contains more than 50 percent of the estimated high-quality deep-sea coral habitat and 45 percent of sponge habitat, despite making up less than 2 percent of the entire area covered by the study. The amount of quality coral and sponges varied in the other canyons, but overall they contained more than other parts of the continental slope.
“In this study, we found Pribilof Canyon to be a hotspot for coral habitat in the Bering Sea,” Miller says. “In a previous study, we showed that these corals seem to be important fish habitat. So if conserving essential fish habitat and corals is important to ocean managers, Pribilof Canyon would be a good area on which to focus their efforts.
“Equally important, our analysis also demonstrates that Pribilof Canyon could be conserved without disproportionately impacting the commercial fishing industry.”
Source: UC Santa Barbara