Etnobiologia do boto-cinza Sotalia guianensis (Van Bénéden, 1864) no litoral oriental maranhense e implicações para sua conservação

Abstract

Local Ecological Knowledge (LEK) is a traditional knowledge accumulated through the observation of nature and can also be transmitted by the generations. Artisanal fishermen, because of their experience and constant contact with the marine environments, are CEL holders on the biology and ecology of the aquatic fauna, knowing the seasonality and distribution of the main species of aquatic fish and mammals with which they share the environments. Among these, we highlight Sotalia guianensis (estuarine dolphin), a small cetacean that inhabits the estuaries from the north of Santa Catarina to Honduras in Central America. Due to its estuarine and coastal distribution, anchovy suffers mainly impacts with marine pollution and accidental catches in fishing nets. Ethnobiological studies with artisanal fishermen are important in order to obtain information necessary for the conservation of the species, but also to help raise the awareness of fishermen about the importance of estuarine dolphin. The objective of this study was to investigate the CEL of the fishermen of Resex Baía do Tubarão, eastern coast of Maranhão, in relation to the ecology of estuarine dolphin. Using semi-structured questionnaires and photographic plates, 113 artisanal fishermen from six fishing communities were interviewed, where they were questioned about species characteristics, behaviors, diet, main places of occurrence and the existence of accidents of porpoises in fishing nets. All the interviewees were male, with a predominant age range of 36-45 years. Of the fishermen interviewed, most of the vessels are motorized and the respondents reported using 13 types of fishing gear, with the haul (n = 16; 14,16%) the most cited. Most fishermen indicated S. guianensis as one of the species of cetaceans that occurs in the area surveyed. The interviewees reported the coloring patterns, feeding behaviors, aerial activities, and displacement, as well as the main species of fish that make up the estuarine dolphin diet. The different communities presented a level of CEL regarding the similar identification and ecology of the estuarine dolphin. The fishermen reported 31 reports of accidental catch and two reports of the use of dolphin meat for bait in order to capture elasmobranchs. The information obtained from the study is important as evidence of traditional knowledge about the dolphin populations of the coast of Maranhão. In this way, establishing partnerships between traditional communities and the scientific community is extremely important, in order to fill the gaps in scientific knowledge, aiming at the conservation of environments and species, especially S. guianensis.