surface floats and radar detectors at each end of the net. The net 

 body is made of monofilament webbing that usually has a vertical 

 profile between the floatline and leadline of two meters and a mesh 

 size of about 15 cm. Each net is 91 m (50 fathoms) long. In the 

 Gulf of Maine demersal gillnets are usually set in a continuous 

 string of 10 to 12 nets that total 914 to 1,097 m (500 to 600 

 fathoms). A single vessel generally sets five or six strings, thus 

 occupying a considerable linear distance along the ocean floor. 



Increased fishing effort is usually followed by increased 

 gear losses, and untended stationary fishing gear such as gillnets 

 are subject to high loss rates. Derelict or ghost gillnets result 

 from storms, entanglement with mobile gear and other causes. 

 Evidence exists that these ghost gillnets continue to catch fish 

 and crustaceans for years and may seriously affect certain fish 

 species (Way, 1977). 



These beliefs and observations developed into charges voiced 

 by the fishing industry before the New England Fishery Management 

 Council. The Council, in turn, requested the National Marine 

 Fisheries Service and the National Undersea Research Program to 

 investigate the ghost net issue and provide information on the 

 gillnet fishery to guide its decision-making, and to take proper 

 action, if necessary, to mitigate gear conflict and the impact of 

 derelict gillnets. 



A three year study was conducted from 1984-1986 by NMFS, the 

 National Undersea Research Program at the University of 

 Connecticut, and the Massachusetts Division of Marine Fisheries. 

 Its purpose was to determine the magnitude of the ghost gillnet 

 problem and the likely impact of these nets on groundfish (cod, 

 pollock, haddock, flounder and lobster). The survey covered 

 Jeffreys Ledge and Stellwagen Bank, two traditional commercial 

 gillnet grounds that have been the center of the controversy 

 between recreational and commercial fishermen (Fig. 1). 



METHODS 



The survey was undertaken with two submersible systems: The 

 Johnson Sea-Link II with the R/V Edward Link and R/V Seward Johnson 

 was used in June, 1984 and June, 1985. The submersible Delta with 

 the R/V Atlantic Twin was used in June, 1986. Both systems 

 employed direct underwater communications and underwater tracking 

 systems that gave the surface vessel a continuous report on the 

 position of the submersible and therefore the positions of ghost 

 gillnets. 



The first year effort established techniques appropriate for 

 a submersible survey and study of ghost gillnets and gillnet 

 fishing areas. We deployed the submersible at sites that had 

 reported ghost gillnets. When we found gillnets, we identified the 



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