| GIS has developed rapidly in response to a burgeoning range of increasingly complex spatial management questions. Although GIS has been investigated and actively promoted for aquaculture support, its use in the sector has been taken up slowly. GIS is not a mapping tool. Its extensive model-building capabilities and the range of decision support tools allow real decisions to be made and trade-off allocations of land, water and natural resource use and their benefits to be evaluated quantitatively. The real power of GIS, and the way that it can be distinguished from all related technologies is in its ability to draw together many diverse and complex factors in order to reach development and administrative decisions. Several mega-regional and national or state level investigations of aquaculture potential have been made based on a wide range of data on environment, infrastructure, resource availability and socio-economics. These macro- and meso-scale GIS models are particularly useful for guiding national plans for resource use, for consideration of food security issues and for investigation of conflict and trade-off between activities. GIS models are also an excellent tool for detailed aquaculture facility location and, in conjunction with remote sensing and direct data collection, can form the basis for continued aquafarm site management and monitoring.
In addition to management benefits, the understanding of processes and events that this approach can engender is very powerful and GIS has a role in research as well as in end-user applications. Remote sensing and GPS are superb data collection methods but it is GIS which provides the framework for models linking biology, physiology, environment, production systems, socio-economics and infrastructure. Overall, GIS has an excellent future in the aquaculture sector. Rapidly expanding access to digital datasets has reduced the time investment in establishment of spatial databases. It is becoming widely adopted, and agencies now expect to see it used in project planning. There is, however, a requirement for sound expertise in the techniques of GIS and remote sensing, and a full understanding of the aquaculture processes involved. It is important to recall that spatial databases and GIS models are created for application-oriented reasons, based on subject-specific rules and can become expert systems in a virtual environment. It is the manipulation of data and modelling of problems within that environment that is the real heart and philosophy of GIS.
Key note speech 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. | 
