Monitoramento de encalhes e levantamento histórico da diversidade de cetáceos (cetartiodactyla) na Paraíba: 1981 - 2017

Abstract

In the coast of Paraíba there are 23 cetacean species with confirmed occurrence, corresponding to 52,3% of the country’s catalogued diversity. The strandings represent unique opportunities to getting to know the species diversity in the region. This paper’s overall goal was to describe the cetacean diversity in the state of Paraíba through stranding monitoring and the evaluation of the material deposited in the UFPB Mammal collection, as well as the database of the CMA/ICMBio. Specifically, we aimed to identify the species and areas with the most concentration of stranding occurrences, and also to gather and systemize the collection data. The monitoring was done between August 2016 and July 2017, totalizing 18 expeditions to the coast of Paraíba, registering 6 Sotalia guianensis strandings during this period. Since 1981 130 species have been catalogued in two databases (CMA/ICMBio and Mammal Laboratory/UFPB), being these 121 strandings, distributed amongst 17 species (73,9% of the species with confirmed occurrence in Paraíba), including the strandings that happened during the monitoring, these being distributed into five families: Delphinidae (58,8%), Balaenopteridae (17,6%), Kogiidae (11,8%), Physeteridae (5,9%) e Ziphiidae (5,9%). Amongst these families, the species with most strandings occurrences were S. guianensis (41,3%), Physeter macrocephalus (13,2%) e Megaptera novaeangliae (11,6%). The stranding variation through the years were of 1-12 ( =3,9±9,9), peaking in 2005, with 12 occurrences. The number of subjects with attested sex was low, containing only 16 males (13,2%) and 6 females (5%). The stranded specimen most frequent age range was adult (24,8%), followed by young (20,7%) and baby (7,4%). It was possible to verify 40 stranding locations, those being most frequent in the central coast (47,9%) and northern (41,3%), adding up to 89,3%. It is believed that the narrow continental platform of Paraíba and the water current system are factors that favor the stranded cetacean diversity, including the strictly oceanic species. Following up with the strandings generate essential data to subside efficient conservationist actions that are adequate to the region, for these represent, for most of the cetaceans, the primordial source to obtain biological material and from the following researches. As such, the systematical monitoring of the strandings is a fundamental practice and should continue in the coast of Paraíba.