| Lake Huron is the third largest freshwater lake in the world and is bordered by the province of Ontario, Canada and the state of Michigan, United States of America. Due to an increased demand for freshwater fishes, and a decline in many wild stocks, there is focus on the aquaculture industry. Various methods for fish farming include cage cultures whereby fish are raised in large, floating cages. This method accounts for most of the freshwater aquaculture production in Canada, rainbow trout (Oncorhynchus mykiss) is the primary farmed fish in Lake Huron. There are nine existing rainbow trout cage culture sites in Lake Huron which account for greater than 60% of the total freshwater aquaculture production from Quebec through Alberta.
In Ontario, the rainbow trout aquaculture industry has had no increase in production from 1996 through 2005, and no new cage culture site licenses issued in the past decade. Contributing to the absence of growth is a regulatory structure involving numerous provincial and federal agencies. To address the complexity of the regulatory structure, representatives from various government agencies and the academic community were brought together to develop Coordinated Guidelines for cage aquaculture site assessment and monitoring. This group identified conditions that would prevent approval of a new site application. A GIS-based decision support tool was proposed to spatially represent the “no-go” criteria and was used to assess the potential expansion of the cage culture industry. Important layers including bathymetry, navigation obstructions, parks, and spawning areas, were compiled in ESRI’s ArcGIS 9.2 ® as raster layers. A “red-zone” map indicates the areas within the lake that are considered “no-go”. The layers were arranged and summarized in a desk-top project so a user can click on the layers and extract the information supporting the “no-go” decision.
The development of a decision support tool for aquaculture resulted in the recognition that a GIS-based model can integrate management objectives with spatial data to create a powerful, user-friendly means to assess aquaculture sites. Ideally, the tool will be developed as a web application to increase accessibility and reduce maintenance costs. Abstract presented at the Fourth International Symposium on GIS/Spatial Analysis in Fishery and Aquatic Sciences in Rio de Janeiro, Brazil, from 25–29 August 2008. | 
