The integration of habitat into management models of aquaculture ecosystems

Jon Granta, Jeff Barrell, Francisco Bravo, and Anne McKee
 
aDept. of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
jon.grant@dal.ca

Simulation models of shellfish and finfish aquaculture have sufficient maturity to be applied to decision support for site selection, expansion, and environmental assessment. Similarly, there is increased awareness of sensitive habitat, critical habitat, and species at risk relative to aquaculture siting in coastal systems. This is also significant in terms of conflict with commercially fished species and their attendant habitat requirements. Statistically-based habitat suitability modelling has been used to predict where various species of interest will be abundant. Predictive vegetation mapping has been used to estimate where marine plants occur, an important advance since SAV are indicators of significant habitat. These tools have been less frequently applied to marine systems, and seldom in the context of aquaculture. Moreover, various habitats provide differing ecosystem services such as denitrification, so their inclusion in traditional tropho-dynamic models is consequential. Taken together, integration of habitat into aquaculture models requires assessment of habitat structure (extent, landscape structure) as well as function.  In ongoing modelling studies oriented toward management of salmon farming, we have incorporated all of these elements to varying degrees. Habitat assessment requires multiple tools including in-water, airborne, and satellite remote sensing. Evaluation of function requires habitat-specific diagenetic models and groundtruth measurements. This presentation reviews our progress in these areas, with field examples and model results for aquaculture sites in eastern Canada.