NOAA releases report on threats to protected species from farm gear as aquaculture expands

A new report on the effects of aquaculture on protected species takes a close look at how increasingly widespread gear may interact with native marine life such as sea turtles, whales and sea birds that are protected under the Endangered Species Act (ESA).

The new study by NOAA’s National Centers for Coastal Ocean Science (NCCOS) pointed to some concerns with aquaculture gear, but also concluded that “risk can be minimized through proper siting, consistent monitoring, and best management practices.”

The rapid growth of aquaculture — over half of the world’s seafood now comes from farming — has left impact studies like this one lagging. According to the report, there is little documentation of how ESA-designated creatures react around aquaculture gear. Because of that, researchers compiled data from fishery gear that is similar to aquaculture gear to provide expanded numbers on the possibility of entanglements. NCCOS researchers also ran their own case study, monitoring longline mussel culture gear in the open ocean.

“The assessment will strengthen the ability of NOAA and other regulatory agencies to make science-based decisions and recommendations as part of the aquaculture permitting process,” said James Morris in a NOAA press release on the study.

Morris, an NCCOS scientist and lead researcher, added that the report outlines what areas require more research.

“We also identified knowledge gaps, provided management recommendations and highlighted areas of needed research," he said.

The report, called “Protected Species and Marine Aquaculture Interactions,” also gathered existing international research, most notably from New Zealand’s extensive shellfish farms. While researchers in New Zealand did find three cases of whales being entangled in mussel spat lines, they concluded that tidy operations with tensioned lines and no loose ropes that are placed outside of migratory paths pose low risk to whales. Dusky dolphins observed over five years in New Zealand largely avoided the mussel farms, and the report concluded that farm gear poses little risk to dolphins and porpoises in general.

Sea turtles and seabirds are also considered to be at low risk. However, baleen whales were at the highest risk from mussel farms because they have difficulty detecting farmed areas, and a tendency to roll when entangled.

Entanglement and ingestion from marine debris is a concern, but the researchers have yet to evaluate what percentage of debris comes from aquaculture.