Análise da estrutura do comprimento da sardinha-laje (Opisthonema oglinum) capturada no Canal de Santa Cruz-PE a partir dos modelos aditivos generalizados para locação, escala e forma

Abstract

Manjuba (Opisthonema oglinum) is the most common sardine in Santa Cruz Channel’s (CSC) landings, located on the northern coast of Pernambuco state. The species is classified as visiting marine origin, as it spends part of its life cycle at the sea and enters estuaries at strategic times. The initial research’s issue focuses on speculating some hypotheses related to the juveniles’ over-catching from O. oglinum species, that are relevant to fisheries professionals on decision-making. The high exploitation of the species and its importance to the economy in the municipalities surrounding the CSC led us to reflect on the need for investigations to promote the sustainable fishing of O. oglinum and, consequently, expand the understanding of the species in the CSC, once the comprehension of the length structure in catches is valid not only to expand knowledge but also to raise hypotheses about the fishing pressure on the resource. The investigation was performed by estimating the standard length of the specimens, using generalized linear models (GLM) and generalized additive models for location, scale, and shape (GAMLSS). After performing the modeling, we observed that the models estimated via GAMLSS enabled a better fit to describe the standard length of O. oglinum compared to those obtained via GLM, according to the GAIC criterion and residue analysis. The Box Cox t Original distribution was chosen to adjust the response variable with the modeling of position and scale parameters. Therefore, we realized the existence of seasonality in the standard length of O. oglinum captured in the Santa Cruz Channel, with the presence of larger individuals in the rainy season, and greater concentration in the center-south region of the channel. On the other hand, the smaller sardines were concentrated near the outflow of the Botafogo River, an area of secondary channels with greater mangrove coverage. We have found evidence that few adults enter the channel and the vast majority of specimens captured in the CSC were young. Thus, it would be pertinent to explore specimens that have completed at least the sexual maturity, since the capture of young individuals can cause an imbalance in the sustainability of the species.