• Deepwater longline survey of the slopes of Porcupine Bank and Porcupine Seabight

      Clarke, M; Hareide, N; Hoey, S (Marine Institute, 2001)
      This survey took place over a period of 12 days in November and December 1999 on the western slope of the Porcupine Bank and the western and eastern slopes of the Porcupine Seabight. Fishing was carried out in five separate areas, in depths between 400 and 2,000 meters. The primary objective of the survey was to obtain samples of chondricthyan and teleost fish for the Marine Institute (MI) deepwater research programme, for contaminant analysis of fish by the MI chemistry section and for food technology analysis at the Teagase National Food Centre. The survey was carried out on a commercial long-liner, using commercial deep-water autoline gear. In total 18 species of chondricthyan, 24 species of teleost fish and 1 species of cephalopod were taken. Among the most abundant species in the catch were bird beak dogfish, leafscale gulper shark, Portuguese dogfish and mora. Over the entire survey, discarding was estimated as 42% of the total catch. The main species discarded were birdbeak dogfish, black mouth dogfish and greater lantern shark. Catch per 1,000 hooks (CPU E) was highest abundances were found in the western and northwestern slope of the Porcupine Bank. The catch rates in the slopes of the Porcupine Seabight were considerable lower. CPUE compared with rates from previous years in the northwestern slope, showed a reduction for the commercial species Portuguese dogfish and leafscale gulper shark.