Conservação de tartarugas marinhas na costa maranhense, Brasil

Abstract

Sea turtles have a long history of human exploitation around the world, which has contributed to the species population decline, along with other threats, mainly by accidental capture during fishing, habitat destruction, and pollution. Currently, interaction with fishing is the largest cause of mortality among sea turtles, followed by ingestion of inorganic material (garbage). The waste accumulation in the oceans, mainly plastic, has attracted considerable attention in recent decades since pollution is a major threat to marine life. In this study, we mapped the occurrence and nesting areas of each sea turtles in the coastal zone of Maranhão; analyzed the frequency of strandings all over the years; and evaluated the impacts on sea turtle populations in the Lençóis Maranhenses National Park, as well as diet composition and ingestion of solid waste. This research includes records of strandings of live or dead animals between 2005 and 2020, coming from the database of the Projeto QUEAMAR – Quelônios Aquáticos do Maranhão - UFMA - Federal University of Maranhão, and bi-monthly campaigns to Lençóis Maranhenses National Park. We observed five species of sea turtles along the entire Coast of Maranhão and reproductive records for two of them. From the impacts observed, anthropic interaction was the most observed factor (n=35), with drowning and amputation being the principal consequences of intermeshing (n=12). Intestinal obstruction caused by ingestion of inorganic material was also frequently observed (n=13). During this research, two Marine Seismic Surveys 3D were conducted to prospect for oil and gas, which coincided with a significant increase in the frequency of strandings in Lençóis Maranhenses National Park, possibly caused by noise pollution through noise swells generated by air cannons. Although the Maranhão coast is covered by legally protected areas, such as the Lençóis Maranhenses National Park and the Cururupu Extractive Reserve, long-term studies with species of international migratory cycle, such as sea turtles, which occupy an important position in the conservation scenario, allows detecting trends and temporal changes, as well as evaluating the impacts of anthropogenic activities in coastal areas.