Encalhes de tartarugas marinhas na costa do Nordeste e Sudeste do Brasil

Abstract

This doctoral thesis had the main objective of describing the spatial and temporal pattern of sea turtle strandings recorded in Brazil between 2011 and 2019, as well as identifying their potential socio-environmental predictors and possible application in public conservation policies. Stranding data was collected within the scope of “Beach Monitoring Project - Projeto de Monitoramento de Praias” (PMP) conducted along the Brazilian coast. The PMPs were carried out in a systematic and standardized manner in three sedimentary basins (Potiguar Basin, Sergipe and Alagoas Basin, Espirito Santo and Campos Basin) that extend from Ceará to Rio de Janeiro states, covering 1274 kilometers of beaches monitored daily. The thesis is composed of three chapters. The first chapter identifies deficiencies in the knowledge management model on marine megafauna strandings currently adopted in Brazil and proposes concrete actions to improve it. The second chapter describes the spatial and temporal distribution of sea turtle strandings along the Brazilian coast and investigates its relationship with the size of the animals. The third chapter evaluates the effects of fisheries management, specifically the closed period for shrimp fishing, on sea turtle strandings. The results indicate that although the Brazilian stranding knowledge management model has strengths, such as comprehensive environmental legislation, a large number of scientists, and numerous prestigious research institutions, stranding data is not effectively translated into technical-scientific knowledge; technical-scientific knowledge is not transformed into strong legal instruments; Deficient legal instruments lead to mistaken decisions and actions that, in turn, result in ineffective conservation and management strategies. Ten improvements are proposed based on a theoretical knowledge value chain model. Between 2011 and 2019, 50085 strandings were recorded, 39796 of Chelonia mydas (79.5%), 6767 of Lepidochelys olivacea (13.5%), 1899 of Caretta caretta (3.8%), 758 of Eretmochelys imbricata (1 .5%), 110 from Dermochelys coriacea (0.2%) and 755 from unidentified species (1.5%). The areas with the highest incidence of strandings varied depending on the species, year and sedimentary basin analyzed, demonstrating that the Brazilian coast needs a joint, well-articulated strategy to conserve the total diversity of the group, especially considering juvenile individuals. The protective effect of the fishing closure on C. mydas was manifested not only during, but also after the 1st closed period (April 1st and May 15th), but disappeared in the 2nd period (December 1st to January 15th). In the case of L. olivacea, protection occurred consistently during and after both closed periods, and even intensified during the last years evaluated in the 1st period (2017-2019). This reinforces the usefulness of the normative instruction that establishes the closed season (IN MMA No. 14/2004) as a protective instrument for non-target species of shrimp fishing. In summary, this thesis reveals that thousands of sea turtles become stranded annually on the Brazilian coast, with great spatial-temporal variation depending on the species; some of the strandings are directly related to unsustainable fishing practices; However, there are alternatives capable of reversing the situation, involving the development of public-private institutional arrangements that correctly manage knowledge about strandings.