Science Response 2021/041

DFO Maritimes Region Review of the Proposed Marine Finfish Aquaculture Boundary Amendment, Whycocomagh Bay, Bras d’Or Lakes, Nova Scotia

Context

We’koqma’q First Nation has made an application to the Province of Nova Scotia to amend their existing sites (#0814, 0845, and 0600) in Whycocomagh Bay, Bras d’Or Lakes, Nova Scotia.

As per the Canada-Nova Scotia Memorandum of Understanding on Aquaculture Development, the Nova Scotia Department of Fisheries and Aquaculture (NSDFA) has forwarded this application to Fisheries and Oceans Canada (DFO) for review and advice in relation to DFO’s legislative mandate. The application was supplemented by information collected by the proponent as required by the Aquaculture Activities Regulations (AAR).

To help inform DFO’s review of this application, the Regional Aquaculture Management Office has asked for DFO Science advice on the Predicted Exposure Zones (PEZs) associated with the proposed range of aquaculture activities, and the predicted impacts on susceptible fish and fish habitat, including sensitive Species at Risk (SAR) listed species, susceptible fishery species, and the habitats that support them.

Specifically, the following questions are addressed in this report:

Question 1. Based on available data for the site and scientific information, what is the predicted exposure zone from the use of approved fish health treatment products in the marine environment, and the potential consequences to susceptible species?

Question 2.Question 2. Based on available information, what Ecologically and Biologically Significant Areas (EBSAs), SAR, fishery species, Ecologically Significant Species (ESS), and associated habitats are within the predicted benthic exposure zone and vulnerable to exposure from the deposition of organic matter? How does this compare to the extent of these species and habitats in the surrounding area (i.e., are they common or rare)? What are the anticipated impacts to these sensitive species and habitats from the proposed aquaculture activity?

Question 3. How do the impacts on these species from the proposed aquaculture site compare to impacts from other anthropogenic sources in the area (including existing finfish farms)? Do the zones of influence overlap with these activities and if so, what are the potential consequences?

Question 4. To support the analysis of risk of entanglement with the proposed aquaculture infrastructure, which pelagic aquatic species at risk make use of the area, and for what duration and when?

Question 5. Which populations of salmonids are within a geographic range that escapes are likely to migrate to? What is the size and status trends of those populations in the escape exposure zone for the proposed site? Are any of these populations listed under Schedule 1 of SARA?

Question 6. The existing sites have been known to experience benthic and pelagic oxygen issues in the past. Given the proposed approach to managing this site and the increased numbers of fish to be cultivated in this area (i.e., 1,000,000 fish), what is the oxygen demand for the area and what does this mean for the balance of oxygen in the area (i.e., will the demand for oxygen exceed the supply of oxygen)?

This Science Response Report results from the Regional Science Response Process of December 1–2, 2020, on the DFO Maritimes Region Review of the Proposed Marine Finfish Aquaculture Boundary Amendment, Whycocomagh Bay, Bras d’Or Lakes, Nova Scotia.

Science Response 2021/041 (PDF, 2,770 KB)

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