Fisheries surveys over broad spatial areas are crucial in defining and delineating appropriate fisheries management areas. Yet accurate mapping and tracking of fishing activities remain largely restricted to developed countries with sufficient resources to use automated identification systems and vessel monitoring systems. For many countries, the spatial extent and boundaries of fishing grounds are not completely known. We used satellite images at night to detect fishing grounds in the Philippines for fishing gears that use powerful lights to attract coastal pelagic fishes. We used nightly boat detection data, extracted by U.S. NOAA from the Visible Infrared Imaging Radiometer Suite (VIIRS), for the Philippines from 2012 to 2016, covering 1713 nights, to examine spatio-temporal patterns of fishing activities in the country. Using density-based clustering, we identified 134 core fishing areas (CFAs) ranging in size from 6 to 23,215 km² within the Philippines’ contiguous maritime zone. The CFAs had different seasonal patterns and range of intensities in total light output, possibly reflecting differences in multi-gear and multi-species signatures of fishing activities in each fishing ground. Using maximum entropy modeling, we identified bathymetry and chlorophyll as the main environmental predictors of spatial occurrence of these CFAs when analyzed together, highlighting the multi-gear nature of the CFAs. Applications of the model to specific CFAs identified different environmental drivers of fishing distribution, coinciding with known oceanographic associations for a CFA’s dominant target species. This case study highlights nighttime satellite images as a useful source of spatial fishing effort information for fisheries, especially in Southeast Asia.

Expert opinion surveys serve as a tool that collects perspectives from various experts, which can be used to enhance the reliability of a tool or study. This paper aimed to validate previously collected climate exposure factors currently impacting small pelagic fisheries and milkfish aquaculture farmers in the Philippines and to validate adaptation measures. The study was conducted through an online survey, where the questionnaire was emailed to experts from various segments of the academe, including non-government workers, and other government researchers, resulting in a total of N=22 respondents. These experts were also asked to rank the exposure factors and the adaptation measures that were taken previously from an online stakeholders’ consultation workshop on small pelagic fisheries and milkfish aquaculture. The survey indicated that the top five exposure factors for small pelagic fisheries were coastal development (due to habitat destruction), water quality, temperature changes, typhoons, and declining catch. For milkfish aquaculture, the top five exposure factors were water quality (leading to fish stock depletion), fry source, temperature changes, typhoons, and salinity. As for adaptation measures, alternative livelihood, establishments of marine protected areas (MPAs), and financial access were identified for small pelagic fisheries, while the development of hatcheries, research, and development for feed formulation, and marketing support are the adaptations identified for milkfish aquaculture farmers. From the results, expert opinion on vulnerability assessments provides a valuable contribution by facilitating faster decision-making to address issues on climate change vulnerability and adaptation in coastal management and sustainable aquaculture.