THE INTERACTION BETWEEN OFFSHORE COD TRAWLERS AND HARP PHOCA-GROENLANDICA AND HOODED CYSTOPHORA-CRISTATA SEALS OFF NEWFOUNDLAND, CANADA

The direct interaction between the seals and the trawl or dragger fish ery results in seals being trapped in trawler nets and either drowned, released, or killed. A study undertaken between 17 and 27 February 19 92 showed that more seals interacted with the net whilst fishing for A tlantic cod Gadus morhua in 450 fathoms of water (10-60 seals) than wh en fishing for witch Glyptocephalus cynoglossus in over 750 fathoms of water (0-6 seals). Seals were captured only whilst fishing for Atlant ic cod (eight harp seals and two hooded seals). Harp seals Phoca groen landica (33.2 +/- 21.8) were more plentiful around the trawler than ho oded seals (0.8 +/- 0.4) and adult male harp seals were most common (7 3%). The impact of the seals on the caught fish was negligible with le ss than 0.002% of the catch being taken by the seals. All observations (n=32) of seals eating Atlantic cod showed that they swallowed them h ead first and whole. The number of seals captured can be reduced by al tering setting methods, and the provision of a runway for the seals ov er the work deck to the side of the trawler would obviate the need to kill them. We hypothesise that the apparent increase in harp seal/traw ler interactions is the result of smaller catches of cod, with consequ ential decrease in spillage from the nets requiring the seals to enter the nets to obtain cod This results in increased by-catch of seals.