Terms of Reference

Identifying potential spawning locations of Asian carps in the Thames River, Ontario based on environmental factors

Regional Peer Review - Ontario and Prairie Region

October 11-13, 2022
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. Concern exists that an invasion of these species in the Great Lakes basin would pose significant ecological and socio-economic impacts.

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. The Asian Carp Program conducts early detection surveillance for Asian carps in Canadian waters of the Great Lakes basin. Locations for surveillance were selected based on tributaries with suitable climatic and physical characteristics to facilitate spawning and promote egg survival and development (Mandrak et al. 2020). Sampling sites within the tributaries are currently selected based on expert opinion and knowledge of the species’ preferred habitat features; however, knowledge of spawning aggregations would improve the efficiency of detection and removal efforts.

The Thames River, a Lake St. Clair tributary, is suspected to be suitable for spawning and recruitment of Asian carps due to its environmental conditions (unimpounded length, flow, temperature). The Thames River is also of increasing concern given that spawning and recruitment of Grass Carp has been documented in two nearby U.S. tributaries in the western basin of Lake Erie, increasing the chance that the Thames will be utilized by mature Asian carps. Narrowing down specific areas within the Thames River that will allow spawning, egg survival, and larval emergence will help the Asian Carp Program optimize targeted sampling activities for adults, eggs, and larvae. The results of this work will also help the Government of Canada to meet its obligations under the International Great Lakes Water Quality Agreement Annex 6.

Objectives

• Identify the environmental and biological factors that would allow Asian carps to successfully spawn in the Thames River.
• Identify the role of environmental factors (flow, temperature) on the timing and location of spawning, and egg and larval development, of Asian carps in the Thames River.

Expected Publications

• Proceedings
• Research Document
• Science Advisory Report

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science, Aquatic Ecosystem Management sectors)
• Ontario Ministry of Northern Development, Natural Resources, and Forestry (NDMNRF)
• Québec Ministère des Forêts, de la Faune et des Parcs (MFFP)
• United States Geological Survey (USGS)
• United States Fish and Wildlife Service (USFWS)
• Michigan Department of Natural Resources (MDNR)
• Academia

References

• Mandrak, N.E., Grafe, S., Lewin, A., Hunter, P., and Heer, T. 2020. Preliminary assessment of the suitability of Canadian Great Lakes tributaries for Asian carp spawning. DFO Can. Sci. Advis. Sec. Res. Doc. 2020/042. iv + 267 p.