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Validated indicators, thresholds, and monitoring protocols for each of the Pathways of Effects (POEs) endpoints for shellfish aquaculture



The aquaculture Pathways of Effects (POEs) describe the linkages between aquaculture activities, stressors and their potential effects on the environment. Building on these interactions, potential indicators and mitigation options can be identified and assessed. POEs for both finfish and shellfish aquaculture were reviewed in 2009 (CSAS-SAR 2009/071) and provided the scientific basis for management decisions under the Fisheries Act.

In 2012, the Fisheries Act was amended to focus on protecting and ensuring the sustainability and ongoing productivity of various fisheries. This project reviewed the shellfish aquaculture POEs that were previously scientifically validated for aquaculture under the old regulatory framework, within the context of these changes to the Fisheries Act. Additional activities or stressors may be identified for shellfish aquaculture POEs. A review of impact indicators and respective monitoring protocols was conducted for each of the POEs endpoints. Thresholds previously established for harmful alteration, disruption or destruction (HADD) of fish habitat were also reviewed to determine their suitability in predicting potential impacts to the productivity of commercial, recreational or Aboriginal fisheries.


The study reviewed each pathway of effect for shellfish aquaculture and suggested indicators that could be monitored to assess the potential impacts of each pathway on the productivity of CRA fisheries. Thresholds for each of these indicators were also suggested and the likelihood of residual effects occurring at current industry practices was determined.

Results will help guide a PARR project (PARR-2017-G-06) with a focus on one of the pathways of effects, change in habitat structure, cover and vegetation, which discusses impacts to eelgrass beds.

Program Name

Program for Aquaculture Regulatory Research (PARR)


2015 - 2016

Principal Investigator(s)

Monica Boudreau
Aquatic Science Biologist, Fisheries and Oceans Canada, Gulf Fisheries Centre, Gulf Region

Team Member(s)

Thomas Landry, Biologist, Fisheries and Oceans Canada, Aquaculture and Coastal Ecosystems, Gulf Fisheries Centre, Gulf Region

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