Spatial and Temporal Dynamics of Suspended Particulate Matter Surrounding Finfish Farms on the East and West Coasts of Canada

Abstract

Achieving optimization of IMTA sites and modeling the efficiency of such a system requires knowledge of the spatiotemporal distribution and variability of TPM surrounding the finfish farms. The objective of this study was to quantify the impact of finfish farms on the surrounding particle field. Platforms equipped with transmissometers, fluorometers and CTD’s were towed around the sites while undulating through the water column in a high-resolution 3D spatial survey approach. In addition, combination turbidity and chlorophyll a sensors were moored at a variety of locations and depths. Surveys were conducted concurrently with the deployment of current meters. Farms surveyed were found to have little impact on the surrounding suspended particle field (mean effect < 1 mg L-1). Results provided evidence of minimal enhancement from fish farm wastes, primarily in surficial waters (0.5- 2 m depth) immediately adjacent to the cages, and evidence of predominantly tidal driven (M2) TPM dynamics.