P-01-06-008
Marine finfish and suspended shellfish aquaculture: Water quality interactions and the potential for polyculture in coastal British Columbia

Although the Environmental Assessment Review of marine salmon aquaculture in British Columbia identified the loss of antibiotics and other water-born contaminants to the environment as a concern with respect to adjacent shellfish stocks and thus to the seafood safety issue, the Review also recommended that the potential for polyculture be explored by the industry.

The sensitivity of shellfish to the water-born contaminants associated with salmon netcage operations (e.g., antibiotic residues, trace metals, complex organic compounds, bacteria), makes their use as biomonitors a useful tool in permitting us to test the spatial (dispersion) and temporal (persistence) influence of these substances in the marine environment. This utility also has important implications with respect to sea food safety given their value in commercial (wild harvest, aquaculture), recreational, and traditional First Nation uses.

However, if the water quality issues related to marine netcage culture are quantified as minimal, or ideally non-existent, then a unique opportunity for shellfish-finfish polyculture becomes available to the aquaculture industry on this coast. Product diversification from the finfish aquaculture sector’s perspective may make such a venture a viable economic consideration, particularly given the opportunity of capitalizing on the use of existing infrastructure (transportation, anchoring, vessels, personnel, marketing, etc.).

Considering the environmental and the sea food safety concerns which have been expressed over the interaction of salmon farming practices and adjacent shellfish resources, a clear, yet scientifically defensible study which will demonstrate the fate and effects of farm-derived materials with respect to adjacent shellfish resources is critically important. Such a study would demonstrate the extent to which waterborne materials are dispersed through the water column, and more importantly IF these materials are bioavailable to shellfish located within these distribution pathways. Results of the study would permit an accurate estimation of the "zone of influence" for the dispersion of such materials, and thus the physical information necessary to determine if finfish-shellfish polyculture is feasible option for British Columbia from a seafood safety perspective.

Project Start Date: February 1, 2001

Project Completion Date: May 31, 2003

For further information please contact: Regional ACRDP Coordinator: Ruth Withler (E-mail: WithlerR@pac.dfo-mpo.gc.ca).