Assessing the stocks of the primary snappers caught in Northeastern Brazilian Reef Systems. 2-A multi-fleet age-structured approach

This study investigates the exploitation of Lutjanus analis, Lutjanus chrysurus, Lutjanus jocu and Lutjanus synagris from multiple gear types in Northeast Brazil using models allowing for technological interactions. The spatial distribution of species and fleets have played an important role in the Northeastern Brazilian artisanal fishery. The results of a predictive model by Thompson and Bell, along with a catch-at-age model, clearly showed that different fleets had distinct effects on snapper stocks. The fishery mortality (F) from small-scale fleets (‘Jangada’ and ‘Paquete’) was higher for coastal species such as L. synagris that are typically found in these areas. Conversely, L. jocu, that inhabits deeper waters, was most affected by motorised and sailing boats. Snappers were exploited differently at each of their life history stages. ‘Paquetes’ mainly exploited juveniles, whereas boats caught larger individuals farther from the coast. As a consequence, effort control through fleet regulation seems to be much more applicable in a tropical context than traditional catch control. Further modelling studies and management options relevant to the Northeast Brazil fishery are discussed.