Littering probably isn’t the problem it once was in this country. Many towns have recycling centers and there are fines for littering. In Massachusetts, if you toss your cigarette out the window on the Interstate it’s not just a slap on the wrist and a lecture on keeping the roads and neighborhoods clean, it’s a crime.
A derelict blue crab trap found in Chesapeake Bay still contains crab. A recent NOAA study looks at the effect of derelict fishing gear upon targeted and non-targeted species in seven fisheries around the country. NOAA photoOnce you leave land and head out to sea there’s a different kind of littering: it’s not something you see but it has an impact. When fishermen — commercial or recreational — lose or discard traps or nets it becomes what’s called derelict fishing gear. And when that gear still catches fish it’s ghost fishing, affecting targeted and non-targeted species.
In Southeast Alaska it’s estimated there are 3,072 derelict traps holding 6,525 Dungeness crabs at any given time. Those figures are a part of a NOAA ghost fishing study entitled “Out of sight but not out of mind: Harmful effects of derelict traps in selected U.S. coastal waters,” that appeared in the September 2014 issue of Marine Pollution Bulletin.
There have been regional studies to try and understand the degree of trap loss but there haven’t been any that look at ghost fishing as a national problem with species specific ecological and environmental impacts.
NOAA is trying to do just that by, initially, bringing together data from seven fisheries — Dungeness crab in Alaska and Puget Sound, blue crab in Maryland, Virginia and North Carolina, spiny lobster in Florida, and coral reef fish in the U.S. Virgin Islands.
The NOAA study focuses on the number of derelict fishing traps in each fishery and their impact on fishermen, target and non-target species and the habitat.
Various methods were used to locate abandoned or lost fishing gear, including divers, side-scan sonar and cameras mounted on a towed sled, ROV or fixed arm from the boat.
The highest density of abandoned gear is in the Maryland portion of Chesapeake Bay with 28 to 75 derelict fish traps per square kilometer. Puget Sound had 44 per square kilometer, and 32 percent of those traps were ghost fishing, with 21 dead crabs and 49 live crabs taken from them.
The fishing grounds around St. John Island in the U.S. Virgin Islands had the lowest density of lost traps at 5 per square kilometer.
The estimated time traps ghost fish varies from 0.3 years in the Virgin Island to more than 6 years in Alaska. Though as the report notes, “some of the traps surveyed were still ghost fishing, which suggests that our estimates of ghost fishing time are conservative.”
The economic impact of ghost fishing can be considerable. The report’s authors estimate that in Puget Sound each year derelict fish traps kill 178,874 Dungeness crabs worth more than $744,000 or 4.5 percent of the annual average harvest.
The report concludes with some suggestions for a derelict fishing trap management program. That includes educating fishing communities on the impact of derelict traps, removing derelict traps, low-cost disposal options and new trap designs. To read the Marine Pollution Bulletin article in full, click here.
