Comparative effects of surface and underwater lighting methods on coastal fishery resources in Terengganu

Abstract The use of artificial light is a common strategy in purse seine fisheries, particularly in Zone C waters off Kuala Terengganu, where it enhances aggregation of pelagic species. This study evaluated the effectiveness of surface lamps versus underwater light-emitting diodes (UWLEDs) through six fishing trips conducted in September 2024. Results showed that UWLEDs accounted for a higher proportion of total catch (53.75%) compared to surface lights (46.25%), with Decapterus russelli being the dominant species. Length-based analysis revealed that UWLEDs disproportionately attracted immature individuals (81.46%) relative to surface lights (80.61%). A Mann–Whitney U test confirmed significant differences between mature and immature groups for UWLEDs catches (p < 0.05), but not for surface lamps. These findings highlight the increased efficiency of UWLEDs but also their higher ecological risk, particularly recruitment overfishing. Regulatory measures on light use are therefore essential to balance fishing efficiency with the sustainability of marine resources.