Seasonal variation in plastic litter pollution in mangroves from two remote tropical estuaries of the Colombian Pacific.

Mangroves in estuaries are highly vulnerable to the impacts of plastic litter pollution, because their location at river mouths and the high capacity of mangrove trees to trap plastic items. Here, we present new results on the abundance and characteristics of plastic litter during high and low rainfall seasons in mangrove waters and sediments of the Saija and Timbiqui River estuaries in the Colombian Pacific. In both estuaries, microplastics were the most common size (50-100 %), followed by mesoplastics (13-42 %) and macroplastics (0-8 %). Total abundances of plastic litter were higher during the high rainfall season (0.17-0.53 items/m-3 in surface waters and 764-832 items/m-2 in sediments), with a moderately positive relationship between plastic abundances recorded in both environmental matrices. The most common microplastics were foams and fragments. Continuous research and monitoring are required for a better understanding and management of these ecosystems and their threats.

Marine litter and microplastic pollution on mangrove soils of the Ciénaga Grande de Santa Marta, Colombian Caribbean.

Marine litter pollution has become a complex global problem, because of the negative ecological and socioeconomic impacts as well as the human health risks that it represents. In Colombia, mangroves are affected by inadequate solid waste management, which results in litter accumulation. Additionally, the information related to this problem is limited avoiding the development of prevention and reduction strategies. For the first time, pollution by marine litter and microplastics were evaluated in mangrove soils of the Ciénaga Grande de Santa Marta, where 540 ±â€¯137 and 31 ±â€¯23 items/ha of marine litter were determined in mangroves near and away from populated centers respectively. Plastics represented between 73 and 96% of litter, and microplastic quantity oscillated between 31 and 2,863 items/kg finding the highest concentrations in mangroves near to the population. This study contributes to the knowledge of the marine litter problem in mangroves of the Colombian Caribbean, becoming a help for their conservation.