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040 |aCaOODSP|beng|erda|cCaOODSP
0410 |aeng|beng|bfre
043 |an-cn-bc|apn-----
045 |ax6x8
0861 |aFs97-6/1611E-PDF|zFs97-6/1611E
1001 |aLeaman, B. M., |d1949- |eauthor.
24510|aBiomass survey of rockfish stocks off the southwest coast of Vancouver Island, September 8-22, 1985 (M/V Howe Bay) / |cby B.M. Leaman, G.E. Gillespie, D.A. Nagtegaal, and R.D. Stanley.
264 1|aNanaimo, British Columbia : |bDepartment of Fisheries and Oceans, Fisheries Research Branch, Pacific Biological Station, |cApril 1988.
264 4|c©1988
300 |a1 online resource (iv, 99 pages) : |billustrations, maps.
336 |atext|btxt|2rdacontent
337 |acomputer|bc|2rdamedia
338 |aonline resource|bcr|2rdacarrier
4901 |aCanadian technical report of fisheries and aquatic sciences, |x0706-6457 ; |vno. 1611
500 |aDigitized edition from print [produced by Department of Fisheries and Oceans].
504 |aIncludes bibliographical references (pages 6-7).
5203 |a"The M/V HOWE BAY was used to replicate a 1979 M/V ARCTIC HARVESTER trawl survey of rockfish (Sebastes spp.) stocks off the southwest coast of Vancouver Island and in U.S. waters off Cape Flattery (approximately 48°4'N to 49°25'N). Seventy-five hauls were completed. Catch rates for nearly all species were notably reduced from 1979 levels, with the catch rates of the four most prevalent species from the 1979 survey falling 80-90%. The 1985 total rockfish biomass estimate of 3,480 t is 49% of the 1979 estimate. Catch rates for Pacific ocean perch (S. alutus) decreased 79% from 1979 levels. The size frequencies of S. alutus showed only a slight increase in modal lengths, and no evidence of substantial recruitment. Behavioral characteristics of rockfish and the characteristics of trawl surveys make absolute estimates of rockfish biomass unreliable, as catch rates may vary highly on the same site through different periods of the day. They are more useful as relative indicators of population trends, in conjunction with other methods. The relative decrease in estimated biomass of S. alutus, when viewed with the lack of recruitment of young perch and the decreases in commercial (84%) and research (59%) catch rates during 1979-1985, indicates further deterioration of the stock, already in poor condition in 1979"--Abstract, page iii.
546 |aIncludes abstracts in English and French.
650 0|aSebastes|zBritish Columbia|zPacific Coast.
650 0|aFish populations|xEstimates|zBritish Columbia|zPacific Coast.
650 0|aFish surveys|zBritish Columbia|zPacific Coast.
650 6|aSébastes|zColombie-Britannique|zPacifique, Côte du.
650 6|aPoissons|xPopulations|xEstimation|zColombie-Britannique|zPacifique, Côte du.
650 6|aInventaires ichtyologiques|zColombie-Britannique|zPacifique, Côte du.
7101 |aCanada. |bDepartment of Fisheries and Oceans, |eissuing body.
7102 |aPacific Biological Station (1972- ), |eissuing body.
830#0|aCanadian technical report of fisheries and aquatic sciences ;|vno. 1611.|w(CaOODSP)9.504449
85640|qPDF|s2.01 MB|uhttps://publications.gc.ca/collections/collection_2025/mpo-dfo/fs97-6/Fs97-6-1611-eng.pdf