| Abstract/Description or Keywords |
Sampling (setlining and angling) for white sturgeon was completed between September 20 and October 30, 2007 over 255km of the mainstem of the Fraser River from rkm 740.7 (Woodpecker Rapids) to rkm 996.0 (Slim Creek confluence). The upper Fraser’s white sturgeon stock is one of four genetically unique/distinct components of the Fraser’s four white sturgeon populations. The upper Fraser population is the smallest and slowest growing of the populations, and therefore inherently susceptible to any event(s) that may cause a decline in the population’s numbers and/or the productive capacity of its habitats. The population was placed on Schedule 1 of Canada’s Species at Risk Act (SARA) in 2006. The population was first assessed from 1999-2001 and estimated at a population of 815 sturgeon _50cm total length. The population was observed to possess a healthy age and size distribution suggesting that recruitment was occurring frequently and successfully. Work in 2007 was undertaken to re-assess the population’s status, begin the process of identifying the stock’s important habitats, and build capacity within Lheidli T’enneh personnel for the purposes of stewarding the stock into the future. In 2007, a total of 35 white sturgeon were captured during the course of sampling, including a single fish that was captured twice (i.e. 34 individuals were captured). Eleven of the 34 white sturgeon captured in 2007 had been captured during sampling programs prior to 2007, including two fish that had been previously captured near rkm 110 in the Nechako River. The total lengths of fish captured ranged from 60-274cm. Aging structures were collected from 24 of the fish captured and the ages of fish captured ranged from 9-78 years, including those that were assigned ages based on previous age determinations. A total of 12 fish were implanted with radio tags. Based on the relatively small sample of fish collected in 2007, the population appeared to be stable. Capture and preliminary telemetry information, indicated important rearing and overwintering habitats appear to exist in the Longworth (Grand Canyon) and McGregor River confluence areas. Capacity building efforts were highly successful. Recommendations are provided to guide additional work of this nature. |
