Lixo marinho como vetor de dispersão de espécies exóticas

Abstract

Exotic species are those that have been introduced, directly or indirectly by anthropic actions, in environments different from their natural distribution. Because they are not native, these species can cause the loss of biological diversity in the place where they were introduced, in addition to harming human health, social and economic activities. One of the vectors for the introduction of species is rafting, which consists of the passive transport of organisms in floating materials, such as marine litter. When adrift in the oceans, these residues – plastic, wood, styrofoam, rubber, metal, fabric, glass, paper and organic waste – can serve as a substrate for the fixation of various organisms, such as bryozoans, mollusks, crustaceans, hydrozoans, polychaetes, algae, among others. In this study, the presence of exotic species in the biofouling of waste collected on six beaches in the Região dos Lagos between November and December 2022 was evaluated. The collected material was analyzed in the laboratory and the species were identified to the lowest possible taxonomic level. In all, 600 solid waste were collected, of which 98 were plastic, metal and fabric with the presence of epibionts. Plastic was the predominant material, present in 97% of the samples. As for the encrusting organisms, 163 specimens were recorded, with emphasis on the Phylum Bryozoa, which was the most representative. Regarding the status of the species, 9 native species, 4 cryptogenic species, 7 exotic species, 5 established and 2 invasive (Megabalanus coccopoma and Saccostrea cf. cucullata) were recorded for Brazil. Due to the high degree of degradation of some residues, it was not possible to identify all the organisms found. The results indicated that marine litter can be an important vector for the dispersion of encrusting species, contributing significantly to the transport of exotic species. The implementation of mitigating measures to reduce the amount of garbage present on the beaches of the Região dos Lagos is fundamental, in view of the role of marine debris as vectors for the dispersion of exotic species. Such measures should be integrated into ongoing Environmental Education programs, capable of promoting behavioral changes and strengthening the local population's awareness of visitors. By limiting the contribution of floating artificial substrates in the marine environment, these actions directly contribute to the reduction of the biological rafting process, thus reducing the risks associated with the introduction and establishment of exotic species in coastal regions.