Mortalidade da megafauna marinha com interação pesqueira na costa do nordeste do Brasil

Abstract

The demand for food resources is growing worldwide and, in this context, marine extractivism provides a source of protein and food security of great importance for human supply, since it produces a quality food with affordable value. Marine megafauna suffers the impacts of this growing exploitation. Although not the target of the fish, the animals inhabit these areas of exploration or dispute the same protein source, causing the negative interactions to happen with increasing frequency. As a result, fishing across the globe has been causing serious conservation problems for species, due to overexploitation and negative interaction with non-target species. The present study aims to diagnose the direct relationship between aquatic mammals and sea turtles strandings and human interactions, aiming to help in public policies that will devise strategies to minimize conflicts that can cause damage to biodiversity. The present work was supported by the Aquatic Mammals Foundation and the State University of Rio Grande do Norte, which collected primary data on aquatic mammal and sea turtle strandings during seven days per week between 2010 and 2016 in two regions of Northeast Brazil, covering five states and 24 municipalities. The data were analyzed with the inclusion of variables, such as: the fishing fleet of the States; data on the municipalities, such as: coastal extension, 2010 census population, estimated population for 2017, HDI, population density, urbanization of public roads and Gross Domestic Product - GDP per capita; weather-related temporal data, and shrimp and lobster closures. During the monitoring period, a total of 11716 sea turtles and 573 marine mammals were recorded, 14.4% (N = 1684) and 28.6% (N = 164) of sea turtles and aquatic mammals, respectively, with interactions related to fishing. All the results indicated a higher number of stranding in the dry period. For the Sergipe/Alagoas Basin, there was a positive effect on the relation between the number of inhabitants per municipality and the number of strandings, with p = 0.023 and R² = 0.42. Sea turtle stranding was more frequent outside the shrimp closure period. The results obtained in this work allow to demonstrate the importance of the monitored areas for the study and conservation of aquatic mammals and marine turtles occurring in Brazil. Analyzes related to shrimp closure and sea turtle strandings found that, during the season, fewer animals are stranded in total, which demonstrates the effectiveness of the closure not only for the target species. The collection of systematized data at regional level, especially in networks of researchers, facilitates the process of analysis and interpretation of results, which may make agile the development of conservation actions.