A study of catches in a fleet of "ghost-fishing" pots

Pots are a form of trap used to capture fishes, crustaceans, or gastropod mollusks. Occasionally, these traps are lost at sea, where they have the potential to fish for many years because they are constructed of robust man-made materials. The present study quantified the mortality and number of animals caught by a fleet of crustacean pots (12 pots) that were set on the seabed and left to fish continually in a manner designed to simulate ghost-fishing off the coast of Wales, UK. The bait originally placed in the pots was consumed within 28 days of the beginning of the experiment. Spider crabs and brown crabs dominated the catches within the pots throughout the experiment. The CPUE of spider and brown crabs declined as an inverse function of time and reached a minimum between 125 to 270 days after initial deployment in August 1995. After this period, CPUE increased again, although it did not attain the rates associated with the beginning of the experiment. The fleet of twelve pots caught a minimum of 7.08 spider and 6.06 brown crabs per pot per year and killed a minimum of 6.06 brown crabs and 0.44 lobsters per pot per year. Other species caught in the traps included velvet swimming crab, lobster, ballan wrasse, dogfish, and triggerfish. The pots continued to catch animals into the second year of the experiment. These results suggest that pots have the potential to fish for extended periods. The wider use of biodegradable escape panels is recommended because currently there is no national legislation in the UK to enforce such escape measures.