Terms of Reference

Comparison of Trapping Methods for Invasive European Green Crab

National Advisory Meeting – National Capital Region

September 28-29, 2021
Virtual Meeting

Chairperson: Sophie Foster

Context

European green crab (Carcinus maenas) is a voracious aquatic invasive species (AIS) that poses a serious threat to Canada’s marine and estuarine ecosystems on the Pacific and Atlantic coasts. They prey on commercial and recreational shellfish, compete with commercial fisheries, and destroy ecologically and biologically-significant habitat, including eelgrass beds, for native species.

Fisheries and Oceans Canada (DFO) has acquired substantial knowledge on European green crab, particularly regarding trapping as a form of physical removal to control their spread. Knowledge acquired includes information on species life history and biology, population dynamics, gear types, and, in some cases, Catch per Unit Effort (CPUE) of trapping gear (e.g., Fukui traps, fyke nets), as well as bycatch, control measures, and mitigation strategies. However, much of this knowledge has yet to be captured formally in a comprehensive review that can be applied to AIS management.

DFO’s AIS National Core Program has requested science advice because trapping of European green crab is critical for early detection, determining impacts on native species and habitat, and control efforts to prevent ecosystem degradation and commercial fishery loss. In order to translate DFO’s scientific knowledge into management action, information on various removal techniques and strategies must be incorporated into decision-making and be adaptable to different situations, such as variation in habitat, gear type, and trapping goals, balanced with operational capacity.

Objectives

1. Review and characterize gear that has been used for trapping European green crab on Canada’s Atlantic and Pacific coasts, considering specific trapping goals (e.g., early detection, ecosystem impact evaluation, population control) and how technologies vary by habitat, organism life stage, by-catch, and catch per unit effort (CPUE).
2. Based on this review, provide recommendations on gear type for trapping European green crab, considering feasibility and logistics.
3. Identify knowledge gaps regarding trapping methods.

The goal of this advice is to provide AIS managers with an overview of existing relevant information regarding European green crab trapping relevant to their trapping objectives. This information could be incorporated by managers into a decision-making tool for guiding action.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO)
• Provinces and Territories
• Indigenous Peoples
• Parks Canada
• Academia