The status of longline fishery in the Kenya Exclusive Economic Zone

The industrial longline fishery is a major fishing method targeting high-value large pelagic species, including tropical tunas and billfish, in the western Indian Ocean. In Kenya, pelagic fisheries are becoming increasingly important, contributing about 35% of total marine fish landings in 2025. Effective management of these fisheries remains challenging because the key commercial species are highly migratory, making data collection costly and difficult. To address this gap, pelagic longline surveys were conducted within Kenya’s EEZ to assess catch rates, species distribution, and the biology of the most abundant species. Seven surveys were completed: five between 2019 and 2020, and two between 2023 and 2024. Each survey lasted at least 24 days, with a total of 153 sampling stations surveyed. A total of 47 fish species were recorded, dominated by Swordfish, Xiphias gladius (49%), Oceanic blue shark, Prionace glauca (17%), Bigeye tuna, Thunnus obesus (8%), and Yellowfin tuna, Thunnus albacares (4%). Catch rates between 2016 and 2024 showed marked interannual variation linked to fishing effort, with no overall decline observed over the study period. Spatially, Swordfish were most abundant in northern coastal waters, while Bigeye tuna and Oceanic blue shark were concentrated offshore. Yellowfin tuna was most abundant in the central and southern parts of the EEZ. Seasonally, catch rates were generally higher during the Southeast Monsoon period (June–September). A greater proportion of immature fish was also recorded during the Southeast Monsoon compared to the Northeast Monsoon season. Maturity analysis showed that 88% of Bigeye tuna, 100% of Yellowfin tuna, and 70% of Oceanic blue shark were mature individuals. In contrast, 66% of Swordfish were immature, suggesting possible gear selectivity effects or the movement of juvenile life stages into Kenya’s EEZ. These findings provide important baseline information to support science-based decision-making and improved management of Kenya’s offshore pelagic fisheries resources.