Resíduos sólidos em áreas de ocorrência de Eretmochelys imbricata e Chelonia mydas e suas implicações para conservação

Abstract

Solid debris incorrectly thrown away become enviromental contamination. Sea debris are one of the main problems for coastal environments worldwide, causing death to many species of its fauna. Debris can affect over 267 species of marine animals wordwide, including 86% of all species of marine turtles. Natural characteristics of their biology make marine turtles specially fragile to such human impact. The marine turtle’s feeding and nesting areas on the coast of Paraíba are conspicuously impacted due to debris coming from different origins, such as coastal activities from local populations and tourists, carried from estuary draining (croming from urban areas) and direct discharge on open sea by comercial and touristic boats. Such impact is a potential cause of death to over 100 marine turtles per year. The ingestion of those materials, causing obstruction of the digestive tract is the main negative interaction registered. Searching for relations between the kinds of debris found on the beaches, foraging sites and stomach content from marine turtles, this study intends to quantify and profile the solid debris found on the beach, the ocean and the digestive tracts of marine turtles. Samplings were performed at sea and six beaches on the state of Paraíba as well as the analysis of 26 gastrointestinal contents of marine turtles (from a total of 200 samples), that had antropic residues on its contents. Sea samplings were performed at Parque Estadual da Ilha de Areia Vermelha (PEMAV) and Picãozinho. The solid debris found on stomach contents were provided by systematic collects realized by the field team of the Guajiru NGO between 2009 and 2012. During the study, a total of 20,700 itens, being 68.904 kg of debris collected – 13,210 itens at beach, 8 on the foraging sites and 7,482 on marine turtles. Plastic corresponded to 60.85% of the itens collected, being 25.17% of the total weight , followed by organic matter 10.13% and nylon 9.85%. the beaches with biggest quantities of debris were the ones with >50 thousand inhabitants, with 6,080 itens (29.37%) of the total sampling and the gastrointestinal contents of marine turtles presented the biggest quantity of solid residues with 7,482 itens (36.14%). Of all marine turtles collected, 16 presented CCL >35 cm and had 3,649 plastic itens on their gastrointestinal tracts, being 3,220 flexible plastic materials and 429 rigid plastic. These data can be applied on integrated coastal management plans, aiming to erradicate the presence of debris and pollution from the oceans. The results demonstrate that the debris on foraging areas have direct antropic origin due to touristic visiting, debris on the beaches are origined by continental draining, direct discharge on the ocean by comercial and touristic ships and principally due to local population and tourists, and that the debris found on marine turtles are not just from the continent, but a result of all the influx of such materials to the ocean.