Steelhead Bycatch and Mortalities in the Commercial Skeena Net Fisheries of British Columbia from Observer Data: 1989 to 2009

, ,

“This report provides a chronological summary of a number of multi-faceted observer/monitoring programs that were conducted in the commercial approach fisheries to the Skeena River (primarily gillnet and seine fisheries in Areas 3 and 4) spanning the last two decades; from 1989 to 2009. Of particular significance is data pertaining to the capture and associated mortality of steelhead by gear type and year. For some years, studies using selective fishing gear or demonstration fisheries are highlighted. Other relevant observations on the catches of target species (sockeye and pink) and other bycatch species (such as chinook, coho and chum) are also included in most summaries. Short-term mortality studies on steelhead and other bycatch species are included when conducted. For some years, outcomes from studies with experimental gears or demonstration (selective) fisheries are discussed.

“Data summaries from observer programs and selective or demonstration fisheries are further analyzed to provide annual estimates of the number of steelhead caught (bycatch) stratified by gear type (gillnet, seine, or experimental gear/fishery) and area (Area 3 or 4) for all years with accompanying data. Most estimates of steelhead bycatch were derived from a simple ratio of observed steelhead to target species (in most cases, sockeye) multiplied by the number of target species reported caught (landed and sold) in the particular strata (after Cochran 1977, and Labelle 1994). Other derivations of this ratio multiplier are also used and described depending on the type and availability of data. All steelhead bycatch estimates are provided with 95% confidence intervals. Estimated 95% confidence intervals for the number of steelhead moralities are also provided for strata where short-term mortality studies were conducted. Steelhead bycatch estimates are further compared to the number of steelhead reported (from sales slips) for all years and from mandatory reports made by fishers (phone-ins and logbook reports) in more recent years (2001 to 2009).”

–Excert for the report’s Executive Summary