Marine debris and pollution indexes on the beaches of Santa Catarina State, Brazil

Marine debris is defined as any persistent solid material disposed into the marine and/or coastal environment. The impact of these pieces of debris, especially plastic, have been reported around the world as causing environmental degradation, disease dissemination, transport of chemical toxins and public health issues. The extent of the effects of marine debris and beach cleanliness can be assessed using indexes such as General Index (GI), Clean-Coast Index (CCI) and Pellet Pollution Index (PPI). Thus, this study analyzed all debris collected from 25 beaches located in 11 counties in the State of Santa Catarina, Brazil. The quali-quantitative analysis was used for individual beaches according to the above indexes. Although plastic was the overall most common debris category, granulated polystyrene was the most common debris in nine of the beaches in this study. From the three indexes employed in this study, GI appears to be the most appropriate as it considers all debris sizes, while CCI underestimates the pollution level of the beaches as it only takes into consideration plastic debris over 2 cm. Similarly, PPI ranked all sites as having low pollution levels, despite the high threats that pellets may pose to marine biota. •Plastic items were the most common collected debris (80% of total sampled).•17 beaches (68%) were classified as extremely dirty considering the General Index.•General Index was appropriate to assess beach cleanness and microtrash threat.•Dissipative beaches located near ports had high concentrations of plastic pellets.