A TECHNICAL ASSESSMENT OF THE USE OF CURRENT GEOSPATIAL TECHNOLOGIES TO DERIVE MARINE FISHERY ADVISORIES IN INDIA AND THE WAY FORWARD

摘要

In India, marine fishers traditionally relied on the various indicators of marine features such as, temperature and colour breaks, feeding patterns of birds, foaming of the sea surface, accumulation of floating objects, etc. Since these parameters are not based on any-scientific inputs directly related to fish accumulation, they often led to inaccurate predictions in detecting the potential aggregation zones. Further, the unpredictable weather conditions in the Bay of Bengal and the Arabian Sea due to periodic tropical cyclones, storm surges, high waves etc., impact the lives and livelihoods of the marine fishers. In order to reduce the uncertainty and risk in the marine fisheries sector for better livelihoods of the marine fishing community, the Government of India emphasizes the use of scientific and technology-driven advisories provided by the India National Centre for Ocean Information Services (INCOIS) in the form of the satellite-derived potential fishing zone (PFZ) and ocean state forecast (OSF) advisories.. The basic inputs for the PFZ advisory include Sea Surface Temperature (SST) and chlorophyll (Chl-a). while OSF is derived using the Regional Ocean Modeling System (ROMS) and General NOAA Oil Modeling Environment (GNOME) etc. To identify the PFZ, remotely sensed data of SST and Chl-a retrieved from the thermal infrared channels of National Oceanographic Aerospace Administration-Advanced Very High-Resolution Radiometer (NOAA-AVHRR) and Eumetsat's Met-Op, and optical bands of Indian Remote Sensing Satellite P4 Ocean Colour Monitor (IRS-P4 OCM) and Moderate Resolution Imaging Spectroradiometer (MODIS-AQUA) data are used. As marine fishes are aggregate in the biologically productive regions where favourable sea temperature exists for their survival, the combined use of Chl-a and SST can be used to delineate PFZ and to generate advisories. On the other hand, the OSF advisories provide a greater sense of security to them and their family helping them to avoid fishing during periods of weather extremities. The use of PFZ and OSF advisories not only enables the marine fishers to increase their catch per unit effort (CPUE) but also facilitates sustainable fishing operations by minimizing fuel consumption of boats venturing into the sea. The present study provides a technical overview of the inputs for the geospatially derived advisories in use and the advantages provided by the selected datasets in identifying the PFZ in the Indian Oceans. From the perspective of recent global developments in the geospatial data acquisition and processing, the present work further provides a critical review of the use of available geospatial datasets and data products which can be useful in enhancing the accuracy of PFZ for marine fishing of India.