Study Reviews Trawler Effects on Seabed

An international group has taken a close look at how different types of bottom trawling affect the seabed. It finds that all trawling is not created equal — the most benign type removes 6 percent of the animal and plant life on the seabed each time the net passes, while the most other methods remove closer to a third. A University of Washington professor is among the main authors on the study, led by Bangor University in the U.K. and published July 17 in the Proceedings of the National Academy of Sciences. The meta-analysis looks at 70 previous studies of bottom trawling, most in the Eastern U.S. and Western Europe. It looks across those studies to compare the effects on the seabed of four techniques: otter trawling, a common method that uses two “doors” towed vertically in the water or along the bottom to hold the net open; beam trawls, which hold the net open with a heavy metal beam; towed dredges, which drag a flat or toothed metal bar directly along the seafloor; and hydraulic dredges, which use water to loosen the seabed and collect animals that live in the sediment. click here to read the story 16:04