Abstract:
This research assessed the feasibility of mapping potential fishing grounds off the coast of Ghana using vessel
trajectories and speeds as proxies for identifying migration patterns and fishing behaviour of inshore trawling
vessels. The methods involved the extraction of data from Satellite Automatic Identification System comprising
position and speed of the vessel from exactEarth Shipview. Daily oceanographic parameters i.e. sea surface
temperature, sea surface height, sea surface salinity, and the current velocity between August 2015- January
2016 were obtained from Copernicus (www.marine.copernius.eu). Speed ranges and trajectories indicate that,
the vessels steamed between 6.9 to 7.5 knots and fish aggregation mostly occurred closer to the shore predicated
on favourable environmental ocean conditions. It was observed that the vessel depicted steaming behaviour in
this study, characteristic of a recreational vessel with high speed, moving in straight paths rather than a trawling
vessel whose movement occurs in slower and erratic trajectory patterns. The findings strongly suggest that the
fishermen operating this trawl vessel have good knowledge of productive fishing grounds. The months with highest
probability of catch aggregation were from October 2015 to December 2015, within the geographical locations of
longitude -4o
2 ʹ E and latitude 3.5o 6 ʹ N. The highest probability of catch aggregation was observed in October
2015, probably due to upwelling that occurred during that month. It is concluded that, fishing efficiency of inshore
trawling vessels in Ghana could be enhanced with maps indicative of probability of fish aggregation in the ocean.
