A systematic review on microplastic pollution in water, sediments, and organisms from 50 coastal lagoons across the globe.

Coastal lagoons are transitional environments between continental and marine aquatic systems. Globally, coastal lagoons are of great ecological and socioeconomic importance as providers of valuable ecosystem services. However, these fragile environments are subject to several human pressures, including pollution by microplastics (MPs). The aim of this review was to identify and summarize advances in MP pollution research in coastal lagoons across the world. We consider peer-reviewed publications on this topic published in English and Spanish between 2000 and April 21, 2022, available in Scopus and Google Scholar. We found 57 publications with data on MP abundances and their characteristics in 50 coastal lagoons from around the world, 58% of which have some environmental protection status. The number of publications on this type of pollution in lagoons has increased significantly since 2019. Methodological differences amongst studies of MPs in coastal lagoons were nevertheless a limiting factor for wide-ranging comparisons. Most studies (77%) were conducted in single environmental compartments, and integration was limited, hampering current understanding of MP dynamics in such lagoons. MPs were more abundant in lagoons with highly populated shores and watersheds, which support intensive human activities. On the contrary, lagoons in natural protected areas had lower abundances of MPs, mostly in sediments and organisms. Fiber/filament and fragment shapes, and polyethylene, polyester, and polypropylene polymers were predominant. MPs had accumulated in certain areas of coastal lagoons, or had been exported to the sea, depending on the influence of seasonal weather, hydrodynamics, anthropogenic pressures, and typology of MPs. It is advised that future research on MP pollution in coastal lagoons should focus on methodological aspects, assessment/monitoring of pollution itself, MP dynamics and impacts, and prevention measures as part of a sound environmental management.

Microplastic pollution in water, sediments and commercial fish species from Ciénaga Grande de Santa Marta lagoon complex, Colombian Caribbean.

Microplastics are emerging pollutants that have been found in different environmental matrices of marine and coastal ecosystems, where they can generate harmful ecological impacts. Little is known about the current state of microplastic pollution in fragile tropical lagoon ecosystems, such as Ciénaga Grande de Santa Marta (CGSM) in the Caribbean coast of Colombia. This study assesses microplastic pollution in surface waters and sediments, and the occurrence of microplastic ingestion in commercially important fish species from CGSM. In waters, microplastic abundances ranged from 0.0 to 0.3 items L-1 while in sediments they varied from 0.0 to 3.1 items kg-1. The most abundant types of microplastics are fibers and fragments, with polypropylene, polyethylene and high-density polyethylene as the most abundant polymers. Also, 100 (i.e. 21.1%) out of 474 individuals from nine fish species had microplastics in their digestive tracts. Microplastics present in water and sediments and in the digestive tract of the analyzed fish species have similar characteristics, also showing a moderate and statistically significant association. Microplastic abundances are higher near river mouths and in urban areas with a high density of fishing activities and aquaculture infrastructures, which are important sources of contaminants. Microplastic pollution in CGSM represents a threat to the lagoon ecosystem and to local people depending on artisanal fishing. Consequently, effective actions to reduce pollution and its socio-environmental impacts are urgently required.

Marine litter pollution in mangrove forests from Providencia and Santa Catalina islands, after Hurricane IOTA path in the Colombian Caribbean.

Marine litter in mangroves comes mainly from poor waste management practices and its abundance is increased by natural catastrophes occurrence that affects coastal settlements, as occurred in November-2020, when two hurricanes (ETA and IOTA) destroyed homes and deposited litters in mangroves of the Providencia and Santa Catalina islands, in the Colombian Caribbean. This study aims to assess the litter pollution in mangrove forests of these islands after Hurricane IOTA. Litter pollution was high in mangroves near urban areas and low in mangroves with little urban influence. In three mangrove sectors with high pollution, litter densities of 0.4-1.4 items m-2 and masses of 0.1-1.2 kg m-2 were determined; the majority were megalitter (sizes >1 m). Plastics were the most abundant (>60%). Local community is aware of the litter pollution problem and their participation in scientific research and mangroves recovery is key to understanding the impacts of natural and anthropogenic events and for ecosystem conservation.