Integration of ecosystem-based models into an existing interactive web-based tool for improved aquaculture decision-making

AbstractProper site selection is critical to the development and expansion of marine aquaculture. Major considerations for site selection include: potential for competing uses, environmental interactions, and animal productivity. Two types of existing site selection tools, mapping and modeling, have proven useful independently, and in some recent studies have proven useful when used together. GIS-based mapping tools have become important in the decision-making process. These tools provide access to marine and coastal datasets allowing farmers and extension agents to gather information on availability of cultivation sites. They are also used by resource managers to assess potential use conflicts (e.g. existence of commercial fishing, mooring areas, fixed fishing gear) and possible environmental interactions (e.g. presence of seagrasses, contaminants, threatened or endangered species). Models have been used separately to predict animal growth, farm productivity, and farm-related effects on the surrounding water and sediment quality.The integration of the Farm Aquaculture Resource Management (FARM) model (http://www.farmscale.org) into the U.S. state of Connecticut's Aquaculture Mapping Atlas (http://seagrant.uconn.edu/whatwedo/aquaculture/shellmap.php) was tested in three geographically distinct waterbodies within Connecticut (CT) waters of Long Island Sound. Nearshore waters within the towns of Mystic, Milford, and Westport were selected as pilot locations to determine usability and capability of the combined tools. Data from two long-term offshore sampling stations adjacent to existing shellfish leases were used to test spatial and temporal sampling variability impacts on model results. Partnerships with local monitoring programs and growers were important for acquisition of water quality data, oyster measurement data, and information about local culture practices. All sites were deemed suitable for oyster aquaculture based on model results that predicted Moderate to High growth based on estimated time to reach harvest size from one in (2.54cm) seed oysters (Crassostrea virginica). Time to harvest varied from 282days (High growth) to 645days (Moderate growth) among the 22 stations in the three nearshore sites, and 724–956days (Moderate growth) at the two offshore sites. Results from the two long-term offshore stations indicate that data from the same year must be used when comparing production-based suitability of sites. Addition of potential production estimates improved the ability to select between suitable mapping-based sites. This mapping and modeling combination should be encouraged to provide a strong basis for successful siting and expansion of aquaculture while minimizing user conflict and adverse environmental interactions. This approach may be particularly useful in waterbodies where shellfish aquaculture is possible but is not well established