Validation of spatial benthic footprint predictions with monitoring of organic deposition

Description

Under the Canadian Aquaculture Activities Regulations, when an aquaculture producer submits a site application, they are required to provide a map of the estimated area of seafloor affected by the aquaculture facility (the “footprint”). This map includes the estimated scale and rate of organic deposition (the organic matter from fish feed and waste that accumulates on the seafloor). The scale and rate of deposition are determined through the use of computer models such as deposit monitoring (DEPOMOD). Fisheries and Oceans Canada is developing a consistent approach to scientifically evaluate applications for marine aquaculture sites. This approach includes modelling what are called “potential exposure zones” (PEZs) affected by organic deposition and chemical use at the proposed sites. While the calculations provide an estimate of the spatial scale of the PEZs , they do not determine the intensity, duration, or frequency of exposure.

In Newfoundland, sites proposed and used for finfish aquaculture have distinct environmental characteristics – they are locations up to approximately 250 m deep, with variable water stratification, and circulation mainly driven by wind. This project will compare the estimated PEZ with the estimated footprint from the DEPOMOD models and with visual observations. This will allow the project team to assess how the PEZ evaluation approach can be better applied to the Newfoundland context. Understanding the spatial extent of organic deposition from aquaculture will also help us assess its potential impact on many species of life (the “benthic assemblages”) on the sea bottom, which depend on sea water and seafloor sediments.

This project will identify the benthic (seafloor) footprint after one year of finfish production, based on the monitoring of seafloor changes. It will compare this footprint with projections from the models (PEZ and DEPOMOD). Results will help to better assess whether short-time data can be used to predict the benthic footprint and to validate modelled outputs. Collecting baseline information at the site will also supply more details on vulnerable benthic species such as corals.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2020-2021

Principal investigator(s)

Dounia Hamoutene, Research Scientist, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Email: Dounia.hamoutene@dfo-mpo.gc.ca

Andry Ratsimandresy, Research Scientist, Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, Newfoundland and Labrador Region

Email: Andry.Ratsimandresy@dfo-mpo.gc.ca

Team member(s)

Fred Page, Senior Research Scientist, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Flora Salvo, Research Scientist, Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, Newfoundland and Labrador Region

Terry Bungay, Senior Technician, Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, Newfoundland and Labrador Region

Susan Haigh, Physical Scientist, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Mitchell O’Flaherty, Physical Scientist, Fisheries and Oceans Canada, St. Andrews Biological Station, Maritimes Region

Collaborative Partner(s)

Elizabeth Barlow, Sustainability Director, Mowi Canada East