Data and derelict fishing gear: implications for monitoring, predicting, and management

Derelict fishing gear (DFG), also known as ‘ghostfishing gear’, describes when fishing gear has been lost, abandoned, or discarded in the marine environment and continues to trap and kill fish, crustaceans, marine mammals, sea turtles, or seabirds. Although it is impossible to get an accurate global number, a rough estimate is that less than 10% of marine debris by volume is DFG. In the context of the Puget Sound, more than 290,000 animals representing 241 unique species have been found dead in removed derelict gear including: porpoise, sea lions, scoters, grebes, cormorants, canary rockfish, Chinook salmon, and Dungeness crab. Crab pots are some of the most common gear lost due to their long soak times as it gives them more opportunity to be affected by currents and adverse weather. It has been estimated that about 12,000 crab pots are lost every year in Puget Sound, costing the commercial fishery up to $700,000 in lost harvest revenue. Furthermore, these crab pots have also been responsible for large cetacean entanglements. While retroactive measures such as removal schemes have been very successful in mitigating DFG, these are costly and need to be made more efficient. Thus, this study aims to help predict the location of DFG through data analytics. Specifically, publicly available databases regarding DFG, ocean currents, and cetacean stranding were overlaid and analyzed. Results show several correlations and trends that could lead to more proactive DFG measures