Impacto do fluxo de embarca??es sobre o comportamento do Boto Cinza (Sotalia guianensis): um estudo de caso para a Ba?a de Sepetiba, Rio de Janeiro, Brasil

• Ano de defesa: 2017
• Autor(a) principal: Mello Neto, Thamires de
• Orientador(a): Sim?o, Sheila Marino
• Banca de defesa: Soares Filho, William, Tubino, Magda Fernandes de Andrade
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Biologia Animal
• Departamento: Instituto de Ci?ncias Biol?gicas e da Sa?de
• País: Brasil
• Palavras-chave em Português: Sotalia guianensis; Impacto; Embarca??es; Ba?a de Sepetiba; Impact; Vessels; Sepetiba Bay
• Área do conhecimento CNPq: Ecologia; Zoologia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/2440

Throughout the coastal habitats, the Guiana dolphin is affected by anthropogenic actions that threaten its conservation, especially fishing and boat traffic. Sepetiba bay seems to offer a high-quality habitat, because the dolphins are very abundant and found in the area all year round. With the industrial development in Sepetiba Bay, there will be an increase of large vessels flow, which will carry several types of cargo, some of which are harmful to the environment and directly dangerous to the animals. This intense traffic occurs in a place used by dolphins for feeding, foraging and breeding, may generate negative behavioral responses, changing their affinity for the place and move away. From a landbase, during the period of one year (July 2015 to August 2016), sightings were realized with the objective of evaluating whether the different vessels generate impacts on the Guiana dolphins? behavior. The evaluation was based on a behavioral reaction classification in Negative, Neutral, and Positive, in interactions with a 500m maximum distance among the study objects. The study had a total of 288 h of sample effort, whereupon with the most interactions were Jan/16 with 14.90% (n = 11), Jul/15 with 13.51% (n = 10) and Mar/16 and Apr/16 with 12.16% (n = 9). Interactions occurred mostly during the period from 10 h to 11 h AM (32.43%), 9h to 10h AM (24.32%), and 11 to 12 h AM (24.32%), and all occurred outside the dredged chanel. The dolphin groups, in general, were small. The presence of calves accompanying the group was also low, only 12 individuals (6.86%). The vessels that most interacted with the dolphins were: Boats (79.73%) and Trawlers (18.92%), and only one ship (1.35%) was observed interacting with the animals. Foraging (57.30%) and Travelling (42.70%) were the most performed activities. The most expressive behavioral reactions were Neutral (71.43%), followed by Negative (24%), and very low occurrence of Positive reactions (4.28%). In order to verify if there were significant differences between the vessels and behavioral reactions, X2 was used, assuming pvalue <0.05 (df 2). It was observed that the Neutral reactions have a differential effect in relation to the other reactions for the types of vessels. Neutral reactions were predominant and could be interpreted as a process of habituation or learning. Or even energy-saving. This energy could be used in foraging activities, since the possible decrease of essential species in their diet will cause a bigger effort to catch prey than avoid potential impacts.