Modelagem matemática aplicada às capturas das principais lagostas desembarcadas em Pernambuco

Lobster fishing is the most economically attractive activity in Northeast Brazil. In this work, the catch variations of the lobsters Panulirus meripurpuratus (red spiny), Panulirus laevicauda (smoothtail) and Scyllarides brasiliensis (Brazilian slipper lobster) in Pernambuco in the years 1999 to 2006 were evaluated to determine trends in monthly production rates and the relationship between the catches made in the closed period and during open season. Seasonal catches were studied from exponential models and correlation analysis. The exponential models were significant and showed determination coefficients above 0.65 for red spiny in all years and for smoothtail starting in 2002, and they described the decline in catches from the beginning to the end of the season. The biomass of the smoothtail showed a more pronounced decline compared to the red lobster, possibly because the capture coefficient would be higher. As for the Brazilian slipper lobster, the models had values of determination coefficients always below 0.40. The correlation between legal and illegal capture was significant only for smoothtail and showed a positive trend. The initial magnitude of the catch for red spiny below 25 tonnes at the beginning of the fishing season can be an alarming indication, whereas for smoothtail, this value can be 10 tonnes. Studies with surplus production models are necessary to better assess stocks and verify the hypothesis that smoothtail would have a higher capture coefficient than that of red spiny.