Geographical Information Systems (GIS) in fisheries
Applying GIS to map the distribution of fishery resources
FAO/FIGIS Species Distribution Maps
Fisheries management is, to a great extent, a space-related problem. Mapping a fishery and the resources should be among the priority tasks when planning for fisheries management and should not be postponed until "complete" information is available, since redundancies or blanks in the information base will more readily appear in the process of elaboration.
Remote sensing for the acquisition of information on fisheries resources location and dynamics is being increasingly used and perfected. Although the direct detection of fish stocks would appear difficult, different techniques are currently under exploitation (e.g. acoustic research) and described in various FAO manuals and publications.
GIS as a management toolMonitoring and analysing spatially-distributed factors such as resources abundance and composition, feeding and reproduction, nurseries, fishing efforts, harvest, tagging and recaptures, trade flows, recruitment, regulatory zoning, control and surveillance, conflicts between gear and fleets, ecosystem conditions, etc. pose major operational and management challenges to fisheries. As already demonstrated in other fields where spatially-related problems occur, Geographical Information Systems (GIS), combined with other analytical tools and models, allow for improved spatial monitoring and analyses and, eventually, better and more effective management practices. Geographical Information Systems are basically integrated computer-based systems which allow the input of digital geo-referenced data to produce maps plus other textual, graphical and tabular output. The essential usefulness of GIS however, lies in its ability to manipulate and overlay data in a large number of ways and to perform various analytical functions so as to produce outputs that could contribute to a faster and more efficient decision making process in fisheries.
As with many computer-based systems, the key to GIS success lies in acquiring suitable geographic data -- that is, information describing the location and attributes of object, including their shapes and representation. Geographic data is the composite of spatial and attribute data. Data acquisition methods vary from simple surveys, questionnaires and counts through to the access of secondary digital databases via online networking capabilities. Once data has been acquired it is only useful to a GIS when it has been formatted, processed or structured in a way which the system will understand. GIS can function in an almost limitless variety of configurations of hard and software.
An example of GIS layering
FAO/Fisheries Technical Paper 449
Before a GIS is implemented into a fisheries management programme, two major considerations must be made regarding: