| Abstract/Description or Keywords |
Sampling (setlining and angling) for white sturgeon was completed between June 11 and October 8, 2008 over 196km of the mainstem of the upper Fraser River from rkm 741.0 (Woodpecker Rapids) to rkm 955 (Longworth Canyon). Sampling also occurred in the lowest portions of the Nechako River (above the Fraser River confluence) between rkm 1.0 to rkm 1.9 and in the Bowron River, above the Fraser River confluence, between rkm 0.2 and rkm 2.1. 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 2008 was a continuation of efforts initiated in 2007 to reassess 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 2008, a total of 34 white sturgeon were captured during setline sampling and 14 white sturgeon captured during angling, including two fish that were captured twice (i.e. 46 individuals were captured). Twenty-four of the 46 white sturgeon captured in 2008 had been captured during sampling programs prior to 2008. The total lengths of fish captured ranged from 48.5 –206 cm. Aging structures were collected from 33 of the fish captured and the ages of fish captured ranged from 4-50 years, including those that were assigned ages based on previous age determinations. A total of 5 fish were implanted with radio tags in 2008. Combined data from 2007 and 2008 sampling indicates the population appears to be stable. Capture and preliminary telemetry information, indicated important rearing and over-wintering 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. |
