00000cam 2200000zi 4500 9.958028 CaOODSP 20251205150441 m o d f cr mn||||||||| 251205t19931993bccab ob f000 0 eng d CaOODSP eng rda CaOODSP eng eng fre n-cn-bc pn----- x9x9 Fs97-4/2185E-PDF Fs97-4/2185E Kieser, R., author. Experimental hydroacoustic estimation of rockfish (Sebastes spp.) biomass off Vancouver Island, November 13-25, 1991 / by R. Kieser, K. Cooke, R.D. Stanley, and G.E. Gillespie. Nanaimo, B.C. : Biological Science Branch, Department of Fisheries and Oceans, Pacific Biological Station, 1993. ©1993 1 online resource (iv, 40 pages) : illustrations, maps. text txt rdacontent computer c rdamedia online resource cr rdacarrier Canadian manuscript report of fisheries and aquatic sciences, 0706-6473 ; no. 2185 Digitized edition from print [produced by Department of Fisheries and Oceans]. Includes bibliographical references (pages 8-9). "The precision of acoustic biomass estimates of rockfish (Sebastes spp.) was examined on the continental shelf off Nootka Sound, British Columbia. We assessed the differences between day and night biomass estimates from areas of about 250, 110, and 30 km² and examined the variability among estimates from several passes on two tracklines. School structure, distribution, and behaviour of S. flavidus was examined acoustically. The species distribution was restricted bathymetrically and its areal extent was governed by bottom slope and topographic features. Diurnal distributions were characterized by dense, vertically stacked schools. Nocturnal distributions showed much more diffuse aggregations, both near bottom and in the midwater. Transitional behaviour occurred very rapidly at twilight. The normal pattern was one of dispersal of diurnal schools in both horizontal and vertical directions at dusk and the subsequent regrouping of nocturnal aggregations at dawn, nearer the bottom"--Abstract, page iii. Includes abstracts in English and French. Sebastes populations British Columbia Pacific Coast. Fish populations Estimates British Columbia Pacific Coast. Fish surveys British Columbia Pacific Coast. Sébastes Populations Colombie-Britannique Pacifique, Côte du. Poissons Populations Estimation Colombie-Britannique Pacifique, Côte du. Inventaires ichtyologiques Colombie-Britannique Pacifique, Côte du. Canada. Department of Fisheries and Oceans, issuing body. Pacific Biological Station (1972- ), issuing body. Canadian manuscript report of fisheries and aquatic sciences ; no. 2185. (CaOODSP)9.505211 PDF 885 KB https://publications.gc.ca/collections/collection_2025/mpo-dfo/fs97-4/Fs97-4-2185-eng.pdf