Fishing with longlines has little effect on the vulnerable ecosystems of the deep sea, according to Telmo Morato and his team at the University of the Azores in Horta, Portugal.

Deep-sea fishing practices such as trawling have proved controversial owing to concerns about damage to slow-growing species at the bottom of the ocean. The researchers studied data from longline fishing, a technique that uses one main line with many shorter, hooked lines attached, around the Azores islands, and compared them to published data on the effects of bottom trawling. They estimate that between 4,000 and 23,000 longline deployments would be needed to remove 90% of cold-water corals in a given area, compared with just 13 trawls.

Regulated longline fishing could be a more sustainable method of deep-sea fishing than trawling, the authors suggest.

Sci. Rep. 4, 4837 (2014)