Local Aquaculture Development Plans (PLDM) are part of a Brazilian public policy for ordering and managing the aquaculture in inland waters, coastal zone and ocean areas. In Santa Catarina state, the PLDMs were conducted by EPAGRI. Geotechnologies were used in four steps: a GIS and spatial analysis participatory approach for aquaculture parks site selection; a hydrodynamic model for simulating pollution dispersion; a surveillance program for water pollution and harmful algal blooms; and a web mapping service for sharing spatial data. The use of geotechnologies on PLDMs, some results, advantages and challenges are presented.
The first step of PLDM was define the suitable sites for aquaculture parks. A participatory GIS approach was adopted to define the main indicators and parameters for spatial analysis, to weigh and to evaluate suitability maps. Indicators of environmental quality, use conflict, law and logistics were considered. The suitability maps were used in public meetings to define the spatial distribution of aquaculture parks. This approach allowed the participatory process where scientists, decision makers and producers worked together for planning the aquaculture parks.
The second step was to develop a hydrodynamic model to evaluate the potential pollution dispersion. The hydrodynamic model generated by the model was exported to a GIS tool in order to facilitate the interpretation and presentation of results. Information about the use of hydrodynamic model in Santa Catarina can be accessed through the web at https://youtube/7KZFGuQuT8s and https://academicworks.cuny.edu/cc_conf_hic/167/.
The third step was the implementation of a surveillance program with publicly available results about the occurrence of harmful algal blooms (HABs) and fecal pollution in aquaculture sites. The program was initiated as a research effort in 2009 and became an official governmental action by means of a legal framework implemented since 2012. Faecal indicator bacteria (Escherichia coli) and phycotoxin levels are measured fortnightly in bivalve samples from shellfish producing zones. The results (http://www.cidasc.sc.gov.br/defesasanitariaanimal/) have led the suspension of the trade of mollusks in numerous HAB events and determined the level of post-harvest treatment required for bivalves proportional to the coliform levels measured in the samples. Currently sampling plans are being redesigned on the light of the new evidences generated by research efforts and outcomes of mathematical models of pollution in coastal areas.
Finally, the PLDM aquaculture parks and coastal monitoring points are available through web GIS (http://ciram.epagri.sc.gov.br/sipldm/) and web site. The main challenge for building an integrated web GIS is managing databases from many sources and the interoperability of diverse web-GIS technologies.