LONG-TERM CHANGES IN RAY POPULATIONS IN THE NORTH-SEA

Three data sets have been analysed: landing statistics (1903-1993), in ternational Bottom Trawl Surveys (1979-1993), and survey data collecte d in Dutch coastal waters between 1951 and 1994. Landings of rays and skates have decreased by more than half compared with the post-war lev el. Starry ray has increased in abundance in the central North Sea bet ween 1970 and 1993. Thornback ray virtually disappeared from the Dutch coastal area in 1958. No significant trend has been observed for the other species. (C) 1996 International Council for the Exploration of t he Sea