Relating frontal features and fishing activity in the Bohol Sea using multi-sensor chlorophyll-a and VIIRS night light data

The relationship between frontal features and fish distributions has been known to be closely correlated. However, the approach of using frontal data in elucidating potential fish aggregations remains to be largely unexplored in the Philippines due to the lack of continuous data. Thus, in this study, the spatiotemporal patterns between frontal features and fishing activity in the Bohol Sea area were analyzed using multi-sensor chl-a and VIIRS night light data. Seasonal map overlays revealed that majority of the areas identified with high frontal frequency were generally found to either coincide or occur close to the dense fishing clusters. Assessment of certain areas of the study domain also suggests that other environmental factors could contribute to the spatial offsets between the fishing clusters and other high frontal frequency areas such as bathymetry or species-specific behavior of certain fishes. The interannual time series of the same areas depicted varied temporal patterns in both the fishing activity and frontal frequency. This is indicative of more localized phenomena that would influence these patterns such as physical oceanographic factors, traditional fishing grounds, or sea conditions and vessel capabilities. This study provides insight into the relationship between frontal features and fishing activity that can be useful for guiding management strategies and decisions for monitoring the country's marine ecosystems and fisheries.