High differences in litter accumulation between rocky shores and reefs in Southeastern Brazil.

Anthropogenic marine litter is sharply increasing and affecting the marine environment. Knowledge gaps exist regarding litter in many environments, including rocky shores and reefs, and the factors driving its accumulation. Thus, this study aims to identify the main drivers of litter accumulation on rocky shores and reefs and to compare their litter composition. The data was collected through underwater visual censuses (UVC) and belt transects and analyzed using generalized linear models and multivariate statistics. Eleven sites were surveyed and more than 80 % of the registered trash was plastic. Litter related to fishery was more abundant on reefs (49 %) than on shores (14 %). Moreover, human density was a significant driver of litter accumulation for both environments, while the distance from the nearest beach was important for reefs, and current velocity for rocky shores. As the identified drivers act differently in the two environments, affecting the sites distinctly, site specific regulations would improve litter management in the region. Furthermore, 55 % of the rocky shores litter was related to water transportation or fishery activities. Thus, educational programs, improvements in disposal management, and cleanups are suggested measures that could curb litter accumulation in the coastal environments of the region.