Terms of Reference

Sampling effort to detect Asian carps during response activities in the Great Lakes basin

Regional Advisory Meeting – Ontario and Prairie Region

January 13–15, 2021
Virtual Meeting

Chairperson: Julia Colm

Context

Asian carps (Bighead Carp [Hypophthalmichthys nobilis], Silver Carp [H. molitrix], Grass Carp [Ctenopharyngodon idella], Black Carp [Mylopharyngodon piceus]) were introduced in the southern U.S. in the late 1960’s for pest control, but later escaped captivity and have spread throughout the Mississippi River basin causing significant losses to biodiversity and ecosystem services. These species are nearing the Great Lakes basin and are anticipated to pose significant ecological and socio-economic threats, should they arrive to the basin (Mandrak and Cudmore 2004, Cudmore et al. 2012, Hayder 2014, Cudmore et al. 2017, Hayder 2019). In response to these threats, DFO developed the Asian Carp Program in 2012, which is based on four pillars: prevention, early warning, response, and management. In addition, all four species of Asian carps were listed under Part 2 of the federal Aquatic Invasive Species Regulations in 2015.

To date, only one species, the Grass Carp, has arrived^{Footnote 1} to the Great Lakes (lakes Erie, Huron, Michigan and Ontario; Cudmore et al. 2017, DFO 2017). Grass Carp reproduction has been documented in two Ohio tributaries to Lake Erie; however, captures of Grass Carp in Canadian waters remain relatively rare. Given the early state of the invasion, efforts directed towards eradication (i.e., early detection and response) are warranted and have been a focus of the Asian Carp Program.

The Asian Carp Program conducts extensive early detection surveillance around the Great Lakes basin and implements a response plan based on the Incident Command System (ICS) following the verified capture of an Asian carp in Canadian waters. When on-water response operations are conducted, the response plan directs intensive, targeted sampling using traditional gears (e.g., boat electrofishing, hoop nets, mini fyke nets, trammel nets, trap nets) around the location of capture. Sampling efforts are scaled up or down depending on the fertility (ploidy), number, species, or life stage of captured individuals. The sampling effort (duration, intensity) and search area are determined at the discretion of the ICS team (made up of program staff and relevant experts), based largely on professional judgement. Professional judgement is employed as scientific information on optimal effort and detection probability of Asian carps during early detection and response efforts is limited for each species.

Previous responses conducted by the Asian Carp Program have occasionally resulted in the capture of multiple specimens; however, it remains unclear how much sampling is required to have confidence that additional fish would be detected if present. The current approach may result in insufficient sampling, leading to Asian carps being undetected, and ultimately, a failure to reduce population density in that location. Alternatively, over-sampling a location may not increase confidence that no additional fish are present, but may reduce the program’s capacity to conduct early detection surveillance elsewhere in the basin due to resource allocation. Science advice is needed to identify best practices for allocating optimal sampling effort during responses. The goal of this science advisory meeting is to identify the relationship between sampling effort (time, intensity, search area) and the probability of detecting Asian carps should they be present in the search area.

Objectives

To determine the sampling effort (time, intensity, search area) required to successfully detect Asian carps, including:

• The influence of density (or occupancy) and abundance on the relationship between sampling effort and catchability;
• The influence of sampling effort on confidence of Asian carp absence; and
• The identification of appropriate sampling effort targets for ending a response or changing response strategy.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO)
• Ontario Ministry of Natural Resources and Forestry (MNRF)
• Quebec Ministère des Forêts, de la Faune et des Parcs (MFFP)
• U.S. federal and state agencies
• Academia

References

• Cudmore, B., Mandrak, N.E., Dettmers, J., Chapman, D.C., and Kolar, C.S. 2012. Binational Ecological Risk Assessment of Bigheaded Carps (Hypophthalmichthys spp.) for the Great Lakes Basin. DFO Can. Sci. Advis. Sec. Res. Doc. 2011/114. vi + 57 p.
• Cudmore, B., Jones, L.A., Mandrak, N.E., Dettmers, J.M., Chapman, D.C., Kolar, C.S, and Conover, G. 2017. Ecological Risk Assessment of Grass Carp (Ctenopharyngodon idella) for the Great Lakes Basin. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/118. vi + 115 p.
• DFO. 2017. Update to the Ecological Risk Assessment of Grass Carp (Ctenopharyngodon idella) for the Great Lakes Basin: Lake Ontario. DFO Can. Sci. Advis. Sci. Resp. 2016/049.
• Hayder, S. 2014. Socio-economic Impact of the Presence of Asian Carp in the Great Lakes Basin. Fisheries and Oceans Canada, Policy and Economics, Winnipeg, MB. 2014-1919. iv + 76 p.
• Hayder, S. 2019. Socio-economic Risk Assessment of the Presence of Grass Carp in the Great Lakes Basin. Fisheries and Oceans Canada, Policy and Economics, Winnipeg, MB. 2019-2032. 99 p.
• Mandrak, N.E. and Cudmore, B. 2004. Risk Assessment for Asian Carps in Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2004/103. iv + 48 p.