Temporal assessment of organic loading from finfish aquaculture on hard bottom communities in Newfoundland

Description

Fisheries and Oceans Canada (DFO) recently developed and is now implementing the Aquaculture Activities Regulations (AAR) to clarify conditions under which aquaculture operators may treat their fish for disease and parasites, as well as deposit organic matter (i.e., uneaten feed and faeces). These regulations permit aquaculture operators to deposit organic matter and treatments within certain restrictions while avoiding, minimizing, and mitigating potential impacts of aquaculture on fish habitat and on commercial, recreational and Aboriginal fisheries. In support of the AAR, there is a need to evaluate monitoring standards and protocols for biochemical oxygen demanding (BOD) deposits (i.e., organic matter) in locations where it is not possible to collect sediment samples (i.e., hard-bottom substrates). So far, research findings suggest that video (i.e., visual) monitoring should be the primary tool for environmental assessment; however, a better understanding of its limitations is necessary.

In order to assess the impacts from unconsumed fish feed and fish faeces on the benthic community, it is necessary to validate video monitoring data with information on the benthic community. Samples of the waste that builds up under finfish farm net-pens will be collected and analyzed for changes in fauna and flora, and specifically for the presence or absence of indicator species (i.e., Polychaete worms and bacterial mats) known to occur near finfish farms. The study will also evaluate the use of remote video survey methods (ROVs) for monitoring benthic impacts, based on the protocol used in British Columbia. The results from this study will support the development of science advice on the best practices for monitoring the effects of finfish aquaculture on the hard bottom benthic community.