Effects of marine reef National Parks on fishery CPUE in coastal Kenya

The role of marine protected areas in conserving fish stocks and their potential influence on adjacent fisheries was studied at Malindi and Watamu Marine National Parks, Kenya (established in 1968). For most species catch per unit effort (CPUE) in traditional Dema traps fished across park boundaries was higher within the parks (up to an order of magnitude). However, a few species (e.g., the seagrass parrotfish, Leptoscarus vaigensis and the whitespotted rabbitfish, Siganus sutor, WSR) had higher seasonal CPUE outside the parks. Potential spillover of fishes from the parks to adjacent fished areas was tested with a logistic “decay” model of density gradients (CPUE) across park borders from fringing and patch reefs. A steep decay in CPUE off the Malindi patch reef suggested little spillover of most species. However, greater spillover was suggested off fringing reefs. Species differences were evident. The two most important commercial species showed different density gradients. Species diversity declined more abruptly off the fringing reefs. We conclude that although spillover of most species from the parks is limited, the most important commercial species exhibits significant spillover to adjacent fisheries and the Parks likely comprise important nursery and growth areas for other species.