Manned Submersible and ROV Assessment of Ghost Gillnets in the Gulf of Maine

In 1984, a three year study began to determine the frequency and impact of lost demersal gillnets in two important fishing grounds in the Gulf of Maine. The surveys were undertaken using the submersibles JOHNSON SEA-LINK II and DELTA in June of each year. Twenty-four submersible transects averaging 0.5 nmi resulted in a survey of 186 acres on 64 nmi²of traditional commercial gillnet grounds of Jeffries Ledge and Stellwagen Bank. Ghost gillnets found were surveyed for net dimensions, vertical profile, fouling, vertebrate and invertebrate catch, and fate of catch. One ghost gillnet found in 1984 was surveyed again in subsequent cruises. Another net found in June 1986 was also surveyed in July 1986; the latter survey employed a Remote-Operated-Vehicle. Extensive video documentation was acquired.