Terms of Reference

Lake Utopia Rainbow Smelt, Large-bodied Populations (LURS-LbP) Population Abundance and Allowable Harm Estimate

Regional Science Response Process – Maritimes Region

October 17, 2017
Dartmouth, Nova Scotia

Chairperson: Tana Worcester

Context

Lake Utopia is part of the Magaguadavic River watershed in southwestern New Brunswick. Lake Utopia Rainbow Smelt (LURS) represent one of the only three confirmed occurrences in Canada where genetically divergent smelt populations co-exist. Two populations of smelt co-exist in Lake Utopia, a small-bodied form (SbP) and a large-bodied form (LbP). Lake Utopia Rainbow Smelt (LbP) was designated as Endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in November 2008. The rationale for the designation was the “population is part of a genetically divergent sympatric pair of Osmerus that is endemic to a single lake in Canada with an extremely small index of area of occupancy (6 sq. km). It spawns in only three (3) small streams in the watershed and could quickly become extinct through degradation of spawning streams from increasing development around the lake shore and impacts of the dip-net fishery. This population is threatened by introduction of exotic species and by increasing eutrophication” (see: COSEWIC 2008). A Recovery Potential Assessment (RPA) for Lake Utopia Rainbow Smelt (Osmerus mordax) (both SbP and LbP) was undertaken in 2010 (DFO 2011). LURS-LbP is currently under consideration for listing as Threatened under the Species at Risk Act (SARA).  A Science Response was completed in 2016 to estimate the population abundance for LURS-LbP based on sampling conducted in 2014 and to provide advice on an appropriate population objective as well as advice on the likelihood that the population objective can be achieved under current levels of mortality. However, the results were inconclusive as there was uncertainty about the genetic assignment of the fish sampled and limitations associated with reliance on data from a single spawning season (DFO 2016). Since that time, genetic analysis has produced relevant information that was not considered in the 2016 Science Response and LURS-LbP was sampled a second time in 2017. The intent of this meeting is to provide updated information on LURS-LbP abundance estimate, abundance target, and allowable harm, where available.

Objective

• Provide a population abundance estimate for LURS-LbP based on sampling conducted in 2014 and 2017 and on genetic analysis undertaken in 2016.
• Provide an updated recovery abundance objective for LURS-LbP to replace the interim recovery abundance objective proposed in the Recovery Potential Assessment (see: DFO Science Advisory Report 2011/004).
• Provide the likelihood that the updated abundance objective for LURS-LbP can be achieved under current levels of mortality.
• Provide the maximum level of allowable harm that LURS-LbP can sustain without jeopardizing survival or recovery.

Expected Publications

• Science Response

Expected Participation

• Fisheries and Oceans Canada (DFO) Science
• DFO Species at Risk Management Division
• DFO Fisheries & Aquaculture Management
• Province of New Brunswick
• Aboriginal groups
• ENGOs
• Academia

References

Bradbury, I.R., R. Bradford, and P. Bentzen. 2011. Genetic and Phenotypic Diversity and Divergence in Sympatric Lake Utopia Rainbow Smelt (Osmerus mordax). DFO Can. Sci. Advis. Sec. Res. Doc. 2011/008: vi + 28p.

Bradford, R.G., P. Bentzen,  and I. Bradbury, I. 2013. Lake Utopia Rainbow Smelt (Osmerus mordax) Status, Trends, Habitat Considerations and Threats. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/124. iv + 42 p.

COSEWIC (Committee on the Status of Endangered Wildlife in Canada). 2006. COSEWIC Assessment Summary – May 2006: Atlantic salmon – Inner Bay of Fundy populations.

DFO. 2011. Recovery Potential Assessment for Lake Utopia Rainbow Smelt (Osmerus mordax) Designatable Units. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2011/004.

DFO. 2016. Estimating Lake Utopia Rainbow Smelt (Osmerus mordax) Spawner Abundance and Allowable Harm. DFO Can. Sci. Advis. Sec. Sci. Resp. 2016/024.