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

How natural disasters affect the distribution of marine litter in protected island ecosystems (Seaflower Biosphere Reserve - Colombia)

Islands are particularly vulnerable to storms and hurricanes, which can cause severe environmental, economic, and social impacts, including the accumulation of waste in marine ecosystems. In November 2020, Hurricane Iota struck the islands of Providencia and Santa Catalina in the Seaflower Biosphere Reserve, Colombia. This study assesses the distribution, composition, and sources of marine litter after the hurricane, focusing on variations observed across coastal ecosystems such as beaches, mangroves, and coral reefs. A comparative analysis of data from 2019 and 2021 reveals significant differences in how the island's diverse ecosystems interact with marine litter, underscoring the impact of extreme events on these environments. While mangroves and back-beach vegetation act as retention zones, particularly for plastic waste, these ecosystems showed a marked reduction in litter density in 2021, likely due to direct removal efforts during recovery and hurricane-driven oceanographic processes that may have redistributed lighter litter. In contrast, sandy beaches experienced an increase in litter following the hurricane, highlighting their greater vulnerability to litter deposition transported by waves and wind during extreme weather events. These findings emphasize the complexity of managing marine litter after natural disasters and underscore the need for enhanced waste management strategies in vulnerable island ecosystems.

Rethinking geological concepts in the age of plastic pollution

This paper attempts to reevaluate traditional geological classifications from sedimentology to stratigraphy as well as the concept of the Holocene/Anthropocene epochs, characterized by the widespread integration of plastics into sedimentary environments. This paper presents a set of novel insights into the interactions between synthetic materials and natural geological processes. We illustrate how plastics not only disrupt sedimentary dynamics and alter the composition of rocks and soils, creating new forms of pollution and also pose escalated threats to marine biodiversity through altered erosion, transport, and deposition patterns. We highlight the emerging role of plastics as distinctive stratigraphic markers, providing a different perspective on human environmental impacts. This analysis challenges the traditional perception of rocks as solely natural, inorganic formations and highlights the critical need for interdisciplinary approaches that meld geology, chemistry, and environmental science. The document calls for intensified research to develop effective strategies for managing these impacts and promotes innovative conservation techniques that address both the symptoms and sources of plastic pollution.

Vulnerability of mangrove ecosystems to anthropogenic marine litter along the southeast coast of India

Human-caused marine pollution poses a constant threat to marine ecosystems, particularly tropical mangrove forests, which are vulnerable to litter from both inland and marine sources due to inadequate waste management. Despite well-documented effects of marine litter on various maritime habitats, its impact on mangrove forests remains underexplored. This study investigates the abundance, composition, sources, and impacts of human-caused marine litter on mangroves along the Thoothukudi coast in the Gulf of Mannar, southeast India. The study recorded an average litter abundance of 6.7 ± 1.2 items/m2 on the mangrove ground and 8.6 ± 0.3 items/tree, with plastic litter comprising over 81 % of all collected litter. Single-use plastic items were the most common across all sites. Several indices, including the General Index, Clean Coast Index, Pollution Load Index (PLI), and Hazardous Items Index (HII), were used to evaluate mangrove floor cleanliness, all indicating poor conditions. The PLI revealed "Hazard Level I" plastic debris concerns, with litter levels varying significantly by location. Areas with high population density and poor solid waste management had significantly more stranded litter. Litter sources were identified as both local (land-based) and external (marine fishing). Trapped plastic was found to impair mangrove pneumatophores and branches. To mitigate the negative impacts on mangrove ecosystems and ensure their conservation, the study emphasizes the need for strict law enforcement, a unified solid waste management strategy, and a widespread behavioural shift among citizens.

Plastic Waste in Latin America and the Caribbean (LAC): Impact on the Environment and Public Health-A Systematic Review

Background

The global spread and accumulation of plastics in freshwater, marine, and terrestrial settings are of great concern to public health and the environment, especially in developing countries with few resources. In the Caribbean and Latin America, nearly 17,000 tons of plastic waste are generated and trashed daily in open dumpsites with attendant consequences for the environment, the economy, aquatic life, the beauty of sea beaches, and public health. The increased use of plastics threatens public health and the ecosystem. Main Body. This systematic review assessed the impact of plastic waste on the environment, economy, and public health in LAC by searching relevant databases such as PubMed, HINARI, Google Scholar, and Scopus. PRISMA and Rayyan software were used to select and analyze research articles for the review.

Conclusions

The review showed that plastic pollution significantly impacts the environment, aquatic life, economy, and human health in LAC. The review further indicated that countries in LAC are working assiduously to address the issues associated with plastic pollution. The use of biodegradable plastics, cleanup campaigns, and policies/programs to reduce or ban plastics are some current efforts in many LAC countries. More research on the impact of plastic waste needs to be conducted, especially in the Caribbean, to address and mitigate the challenges of plastic pollution.

Wind- and rain-driven macroplastic mobilization and transport on land

Wind and rain are considered main drivers for mobilization and transport of macroplastics on land, yet there is a lack of empirical data that quantifies this. We present lab experiment results on land-based macroplastic mobilization and transport. We placed four types of macroplastics on terrains with varying surface roughness and slope angles, and exposed them to changing wind speeds and rain intensities. In general, we find that the mobilization probability and transport velocity of macroplastics strongly depend on the combination of the terrain characteristics and material properties. At Beaufort 3, 100% of the plastic bags were mobilized, whereas for the other plastic types less than 50% were mobilized. We found 1.4 (grass) to 5 times (paved surface) higher mobilization probabilities on land than assumed by existing plastic transport models. Macroplastic transport velocities were positively correlated with wind speed, but not with rain intensity. This suggests that macroplastics are not transported on land by rain unless surface runoff develops that can bring the macroplastics afloat. Macroplastic transport velocities were, driven by wind, 1.9 and, driven by rain, 4.9 times faster on paved surfaces than on grass. This study enhances our understanding of land-based macroplastic transport and provides an empirical basis for models.

Mangroves in the "Plasticene": High exposure of coastal mangroves to anthropogenic litter pollution along the Central-West coast of India

Anthropogenic litter is a ubiquitous stressor in the global ocean, and poses ominous threats to oceanic biodiversity and ecosystem functioning. At the terrestrial-ocean interface, tropical mangrove forests are subject to substantial exposure to mismanaged litter from inland and marine sources. While the effects of litter in different marine ecosystems are well-documented, research on the ecological consequences of litter pollution on mangroves remain nascent stage. Here, we investigated anthropogenic litter concentration, composition, probable sources, and impact on coastal mangroves along the Central West coast of India. The mean concentration of trapped litter was measured 8.5 ± 1.9 items/m² (ranged 1.4 ̶ 26.9 items/m²), and 10.6 ± 0.5 items/tree (ranged 0 ̶ 85 items/tree) on the mangrove floor and mangrove canopy, respectively. Plastic dominated 83.02 % of all litter deposited on the mangrove forest floor and 93.4 % of all entangled litter on mangrove canopy. Most litter comprised single-use plastic products across all surveyed locations. Mangrove floor cleanliness was assessed using several indices, such as Clean Coast Index, General Index, Hazardous Items Index, and Pollution Load Index, reiterating an inferior cleanliness status. The pollution load index indicates "Hazard level I" plastic pollution risk across the mangroves. Litter concentration differed markedly across all sites. However, a significantly higher concentration of stranded litter was detected in the densely populated urban agglomeration and rural areas with inadequate solid waste management. Probable sources of litter indicate land-based (local) and sea-originated (fishing). Supportive information on the transport and accumulation of marine litter is examined based on the National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS) model version 2 reanalysis of surface wind and current pattern across the Arabian Sea followed by MIKE simulated tide-induced coastal current. Mangrove pneumatophores and branches were found to be damaged by entangled plastics. Hence, determining litter quantum and their probable input source is pivotal in mitigating anthropogenic litter impact on mangrove ecosystems and fostering mangrove conservation. Overall, results envisage that stringent enforcement, implementation of an integrated solid waste management framework, and general behavioral change of the public are crucial to mitigate litter/plastic pollution.

The Plasticene: Time and rocks

Plastics, "yesterday's hero... today's villain" or "the contemporary symbol of modernity," were invented in the early 20th century by Leo Hendrik Baekeland from macromolecules (resins, elastomers, and artificial fibres) of formaldehyde and phenol. This synthetic organic polymer took hold of daily human life and transformed the modern world with an ever-widening range of applications. Plastics are the third most-widely manufactured material in the world after cement and steel, and they have become widespread in our society with excessive production and consumption to meet demand. Plastics use is so dominant that they are inappropriately considered essential in the world consumers marketplace. Plastics are a clear indicator of the Anthropocene and can be considered the marker of the upper subdivision of this stage: the Plasticene.

Landward zones of mangroves are sinks for both land and water borne anthropogenic debris

The hotspots for mangrove diversity and plastic emissions from rivers overlap in Asia, however very few studies have investigated anthropogenic marine debris (AMD) pollution in these threatened coastal ecosystems. Despite Hong Kong's position at the mouth of the Pearl River, a major source of mismanaged waste in Asia, the mangroves in Hong Kong have never been extensively surveyed for AMD. Here we assessed the patterns of AMD abundance within 18 mangrove forests across Hong Kong surveying both their landward and seaward zones. We recorded and categorised, according to their material and potential uses, both the amount of debris items and area they covered, to better quantify its potential impact on the mangroves. Across Hong Kong mangroves, the average abundance of debris was 1.45 ± 0.38 (SE) items m^-2, with an average coverage of 6.05 ± 1.59%. Plastic formed a high proportion of AMD accounting for 70.31% by number of items and 49.71% by area covered, followed by glass/ceramics and wood/bamboo. Disposable food packaging, fishing gear and industrial and construction related waste were the major sources of AMD we documented. On average, we recorded about six times more debris items m^-2 at the landward sites than at the seaward one, but these abundances varied between the East and the West coastlines of Hong Kong. Our data confirms the hypothesis that landward areas of mangrove forests act as traps and retain marine borne debris, but they also suggest that direct dumping of waste from the land could represent a serious impact for these forests placed in between the land and the sea. More research is needed to ascertain the impact of land disposed debris on mangrove degradation, and this study strongly advocates for a cultural shift about the perception of these forests by the public.