Status of White Sturgeon in the Lower Fraser River, British Columbia

Abstract

Sturgeon (Acipenseridae) stocks worldwide are generally in decline, with many populations close to extirpation. One prominent species, the White Sturgeon (Acipenser transmontanus) with spawning populations distributed throughout three large, western North American watersheds (the Sacramento, Columbia, and Fraser rivers), has experienced population declines in the past decade. In 2003, the Committee on the Status of Endangered Wildlife in Canada designated all six populations of White Sturgeon in Canada “endangered.” To assist sturgeon recovery initiatives in the lower Fraser River (British Columbia), a stewardship‐based monitoring and assessment program was developed by the Fraser River Sturgeon Conservation Society. A descriptive population model was developed to provide reliable annual population estimates by size/age group and location, based on tag release and recapture data collected by trained volunteers. As of January 2011, the population estimate (from 40‐ to 279‐cm fork length) was 44,713 (95% confidence level 42, 634–46, 792). Group size analyses suggest that abundance decreases have been greatest for juvenile sturgeon under 100‐cm fork length. Recruitment decline may be the result of several factors, including destruction of important spawning and early life history rearing habitats; fewer successful adult spawners due to in‐river fisheries; and/or impacts of reduced food supply and ecological imbalances on both early life and adult stages.

Annual Movements of Acoustic‐Tagged White Sturgeon in the Lower Reaches of the Fraser River and its Tributaries

“…In Canada, White Sturgeon are of cultural and economic importance. The species has been important to aboriginals for generations (Nelson et al 2013b), actively targeted by anglers (Inglis and Rosenau 1994), and at one time was commercially exploited (Semakula and Larkin 1968), although overfishing caused the fishery to collapse at the turn of the last century (Echols and FRAP 1995;Ptolemy and Vennesland 2003). White Sturgeon are long-lived, latematuring fish (Semakula and Larkin 1968); thus it is not surprising that populations have been slow to recover from the great declines caused by overfishing.…”

Research Tools to Investigate Movements, Migrations, and Life History of Sturgeons (Acipenseridae), with an Emphasis on Marine-Oriented Populations

“…The use of uniquely identifiable tags can provide comparative growth and condition information for long-term studies with adequate sample sizes [68]. Length data (i.e., fork length) collected during initial tag release events and again during subsequent recaptures can be used to calculate daily growth rates for individual fish (based on the number of days at large between the release and subsequent recapture events).…”

“…Length data (i.e., fork length) collected during initial tag release events and again during subsequent recaptures can be used to calculate daily growth rates for individual fish (based on the number of days at large between the release and subsequent recapture events). Daily growth can be expanded to provide estimates of annual growth, which in turn can be pooled and averaged for size/age groups of fish; these comparative data can provide insights regarding changes in overall population growth rates and condition over time [68].…”

“…Popular PIT tag insertion locations are in the body cavity, base of pectoral fin or dorsal fin (or between base of dorsal fin and lateral line), and behind head plate (left or right of dorsal line). The position behind the head plate (Figure 4) has gained popularity in recent years due to lower tag loss rates and also based on concerns regarding potential human consumption of tagged sturgeon (tags in the “head” area are less likely to be consumed [68]). PIT tags used for sturgeon are typically 2 mm in diameter and 10–14 mm in length.…”

Drying Times: Integrating Citizen Science to Examine Survival of Florida Largemouth Bass in a Coastal Refuge Habitat

“…Examples from other areas in Florida have shown that the exclusion or alienation of stakeholders in resource management can lead to stakeholder frustration and a lack of acceptance and compliance with management decisions (Suman et al 1999). The creation of citizen science programs similar to this study has the potential to better integrate anglers into restoration and conservation efforts (Nelson et al 2013), with clear benefits in the form of public support and improved research results.…”