Lost or discarded fishing gear is a death trap for marine life.
The gear “ghost fishes” in the world’s oceans, rivers and bays. The derelict gillnets, traps/pots, longlines and trawls keep trapping and killing fish, crustaceans, marine mammals, sea turtles and seabirds for years after fishermen stop tending them, NOAA says in the 2015 study “Impact of ‘Ghost Fishing’ via Derelict Fishing Gear.”
The result: depleted fish populations, damaged coral reefs and marine fauna, more marine pollution and diminished recreational and commercial catches.
The scope of the problem is daunting. A 2009 United Nations study found that ghost-fishing gear makes up 10 percent, or about 640,000 tons, of marine litter worldwide.
NOAA says a recent study estimates that more than 85,000 ghost lobster and crab traps are scattered through the Florida Keys National Marine Sanctuary alone. The agency also reports that on a typical summer day there are 250,000 crab traps deployed on Chesapeake Bay. It estimates that Bay watermen lose 30 percent of the traps each season due to float lines being cut by propellers or chafed through by wave action or currents.
A one-year Washington Department of Fish and Wildlife survey of derelict shrimp pots found that the pots could capture 3,796 to 7,580 endangered rockfish a year. Another Washington study, in 2010, reported that 870 ghost gillnets recovered from Puget Sound contained more than 32,000 marine animals, including 960 fish (22 species), 509 birds (15 species), 23 mammals (four species) and 65 species of invertebrates.
The types of derelict gear most often cited for ghost fishing are in order of prevalence gillnets, pots/traps, bottom trawl nets and longlines, NOAA says. Ghost-fishing gear, which includes monofilament cast off by recreational anglers, tends to aggregate in convergence zones, or “hot spots,” where winds and currents gather marine debris, including fishing nets hundreds of meters long and huge balls of net.
The best known of these zones is the North Pacific Subtropical Convergence Zone near the northwestern Hawaiian Islands, where — since 1996 — federal and state agencies have removed hundreds of tons of derelict nets from coral reefs in an effort to restore fragile habitat and reduce the gear’s impact on marine fauna. Similar aggregations of gear can be found in South Pacific and North Atlantic convergence zones, NOAA says.
The Hawaiian reefs cleanup cost $25 million, NOAA says, but other volunteer cleanup efforts are costing much less and generating income by recycling derelict gear collected from fishermen or recovered from the ocean.
One of these efforts is the Fishing for Energy Partnership, an alliance of the National Fish and Wildlife Foundation; NOAA’s Marine Debris Program; Covanta, a Morristown, N.J., energy-from-waste company; and Schnitzer Steel Industries, a metals recycler in Portland, Ore. The partnership has removed more than 3 million pounds of old fishing gear and marine debris from U.S. waterways and coastlines since 2008 and converted it into enough clean energy to power 2,200 homes for a month, it says.
"Together, with the help of fishermen in over 49 communities across the nation, we are ensuring retired gear is disposed of properly and not 'fishing' longer than intended,” says Nancy Wallace, director of NOAA’s Marine Debris Program.
One way to prevent derelict gear from becoming “ghost gear” is to teach fishermen to turn their worn-out nets and traps in to their port for recycling instead of dumping them into the ocean.
The port of Wellfleet, Mass., has collected 367,000 pounds of old gear from fishermen since 2008. Other high-volume collection points are Newport, Ore. (352,480 pounds); New Bedford, Mass. (285,000 pounds); and Point Judith, R.I. (242,000 pounds).
"Each participating port has helped us to reach this milestone by promoting this free program to their fishermen," says Michelle Pico, the NFWF's marine conservation director.
Another group, Healthy Seas, based in Europe, is sending divers out to recover ghost nets from the Adriatic and North seas, and has been scouting the Mediterranean Sea and the California coast for future cleanups. Healthy Seas says it recovers the nylon nets, cleans them of organic, plastic or metallic material, and recycles them into econyl, a regenerated nylon yarn. Manufacturers are using the yarn to produce apparel and other textiles — socks, underwear, swimming suits and carpet tiles.
Healthy Seas says it is involving fishermen and port authorities in collecting and recovering used nets that otherwise would be destined for incineration — in the best case — or dumping into the ocean or a landfill. The organization recently enlisted the support of Norway’s Egersund Group, a global fishing supplier, as a ghost buster, raising awareness among fishermen of the need to properly dispose of derelict gear.
The Healthy Seas initiative “fits in with Egersund Group’s commitment to developing a business model that aims to enhance sustainability in the fishing industry and aquaculture,” Egersund managing director Geir Henning Risholm says.