Improving the value of management advice using genetic and acoustic telemetry tools to reveal Atlantic Cod population structure and to examine conservation for the Gilbert Bay Marine Protected Area

Description

The goal of this project was to develop an improved ability to distinguish Atlantic Cod population structure using genetic techniques, including the Gilbert Bay cod population, and apply this information to improve fisheries management advice. The protected Gilbert Bay Atlantic Cod population has low numbers and the intent of this research was to be able to genetically determine what proportion of cod caught near Gilbert Bay is actually those that originate from the bay. To achieve these outcomes, this project sought to:

1. measure genetic diversity among Atlantic Cod populations;
2. develop a genetic measure of adaptation that occurs in response to environmental conditions and habitat; and,
3. measure effectiveness of the Gilbert Bay Marine Protected Area (MPA) regulations.

Identifying Gilbert Bay cod from other Atlantic Cod caught commercially would demonstrate the usefulness of genomic tools in conservation and resource management.

The Gilbert Bay cod population, which is protected by a Marine Protected Area (MPA), has excessively high genetic variation (a well-known indicator of a genetically healthy population) in comparison to fish from the offshore Labrador and the Newfoundland shelf. Using acoustic telemetry, which tracks the fish from sound signals emitted by tiny tags inserted into their bodies, scientists identified areas outside the protected area that are frequented by Gilbert Bay cod and learned when Gilbert Bay cod utilize these habitats. To test the relationship between Gilbert Bay cod behavior and genetic distinctiveness, researchers genetically analyzed tissue from individual cod caught commercially outside the protected area, and determined what proportion are Gilbert Bay cod versus other cod. The movement patterns of tagged fish caught outside the protected area were tracked using an existing acoustic telemetry system. The project tested the theory that cod, genetically identified as Gilbert Bay cod, would return to a specific location in Gilbert Bay to overwinter and other cod would not.