Science Response 2013/003

Potential Impacts to Wild Fish Populations and Habitat in the Vicinity of a Proposed Finfish Aquaculture Site in Shoal Bay, Halifax County, Nova Scotia

Context

On April 17, 2012, Fisheries and Oceans Canada's (DFO) Habitat Management Division, Maritimes Region, requested that DFO Science provide advice on three issues pertaining to a proposed finfish aquaculture site in Shoal Bay, Nova Scotia (NS), in order to determine if it is likely to result in negative impacts to fish and fish habitat: the potential for organic enrichment, the potential impacts to wild salmon populations, and the potential uses of habitat by commercially important species and the presence of critical or valuable habitat for these species.

The request for advice is to support Habitat Management’s review of an aquaculture project proposal pursuant to the Canadian Environmental Assessment Act.  As part of the federal Environmental Assessment (EA) process, DFO may provide advice to Transport Canada regarding any impacts that fall under DFO’s mandate. In addition, DFO may provide advice to the Nova Scotia Department of Fisheries and Aquaculture on the proposed aquaculture development. The Canadian Environmental Assessment Registry reference number 12-01-66202 can be referred to for more information regarding the EA of this proposed development project. 

Specifically, Habitat Management asked the following questions with respect to:

Organic Enrichment

1. When running DEPOMOD with resuspension off, what is the area of sensitivity for organic enrichment predicted for the proposed aquaculture site at Shoal Bay based on a stocking level of 500,000 fish at the
   1. maximum daily feed rate?
   2. average daily feed rate?
      
      
2. When running DEPOMOD with resuspension on, what is the area of sensitivity for organic enrichment predicted for the proposed aquaculture site at Shoal Bay based on a stocking level of 500,000 fish at the
   1. maximum daily feed rate?
   2. average daily feed rate?
      
      
3. At what daily feed rate would the deposition rate of 5 g C m^-2 d^-1 be exceeded at the site and what level of stocking would that support when running DEPOMOD with
   1. resuspension on?

Wild Salmon Populations

4. What wild salmon populations (and their lifecycle stages) are known to be or are potentially present in the vicinity of the proposed finfish aquaculture sites at Shoal Bay, Nova Scotia and what is their relative abundance?
5. During which times of the year and for what duration would wild salmon be expected to be in the vicinity of the proposed aquaculture site?  
6. What freshwater habitat found within the range of the Southern Uplands designatable unit is currently used by wild salmon as spawning habitat?

Fish Habitat and Other Fish Populations

7. Based on the type of habitat (as shown in the benthic video) and the site depths and locations (shown on attached map), what are the potential uses of that habitat by lobster, crab, groundfish, clams, scallops, sea urchin, and any other commercially important species?
8. Within the general vicinity of the proposed aquaculture sites, are there species that are not listed in the attached table that are particularly important for fisheries resources, and is there any critical or valuable habitat for these species in the area?

This Science Response Report results from the Science Special Response Process of May 2012 on the Review of the Potential Impacts to Wild Fish Populations and Habitat in the Vicinity of a Proposed Finfish Aquaculture Site in Shoal Bay, Nova Scotia. A meeting to review this Science Response was held on June 14, 2012.

Complete document (PDF, 3177 KB)

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