Experimental gill net fishing on trawlable and untrawlable areas off northwestern Vancouver Island, from the MV Caledonian, August 15-28, 1989 / by K.R. Matthews, J.R. Candy, L J. Richards, and C.M. Hand. : Fs97-4/2046E-PDF

"This report summarizes cruise results from a fishing vessel operating off northwestern Vancouver Island between August 15-28, 1989. The purpose of the survey was to describe rockfish communities on hard (untrawlable) bottom and compare them to those found on smooth-bottom (trawlable) areas. In order to fish hard-bottom areas, the MV CALEDONIAN, a chartered commercial trawl vessel, deployed and retrieved sunken gill nets. Fishing was conducted on the continental slope between 200-300 m on two habitat types: hard-bottom habitat considered untrawlable and smooth-bottom habitat typical of trawlable areas used by commercial trawlers. Species composition differed between the two areas. Catches on untrawlable bottom included lingcod Ophiodon elongatus, thornyhead Sebastolobus alascanus, and 13 rockfish species but were dominated by four species: sharpchin rockfish Sebastes zacentrus (70%), red-banded rockfish S. babcocki (4%), greenstriped rockfish S. elongatus (4%), and bocaccio S. paucispinis (4%). Although the same number of species were caught on trawlable bottom, catches were dominated by Pacific ocean perch Sebastes alutus (37%), splitnose rockfish S. diploproa (23%), greenstriped rockfish (13%), and bocaccio (7%). In addition, significantly more fish per set were caught on hard-bottom (untrawlable) areas: 78.3 fish (rockfish and lingcod)/set on untrawlable bottom, compared to 31.0 fish/set on trawlable bottom. Differences in numbers/set and species composition indicate differences in fish assemblages in the two areas"--Abstract, page iii.

Lien permanent pour cette publication :
publications.gc.ca/pub?id=9.956912&sl=1

• Format MARC XML
• Format MARC HTML

Demander des formats alternatifs