Where does marine litter hide? The Providencia and Santa Catalina Island problem, SEAFLOWER Reserve (Colombia)

Macrolitter contamination in beach, dune, and mangrove ecosystems on a Caribbean island: A comparative analysis

Litter pollution is a global issue that threatens biodiversity and ecosystem services, especially on vulnerable islands. This study assesses and compares the abundance and composition of macrolitter, including plastic bottles, and identifies its sources across beach, dune, and mangrove ecosystems in Jamaica. The highest macrolitter abundance occurred on the beach (12 items m-2), followed by dune (4.3 items m-2) and mangrove (1.8 items m-2) ecosystems. Plastics dominated (83 %-99 %), with sizes ranging from 2.5 to 25 cm (91 %-99 % of the items), and most had lifetimes shorter than one year (60 %-82 %). Lightweight items easily transported by wind accumulated in the dune, while floating items carried by tides prevailed in beach and mangrove ecosystems, with similar plastic bottle abundances (0.3 items m-2). Result showed that the primary causes of macrolitter contamination in all three ecosystems are poor waste management and recreational activities. Whereas most (54 %-84 %) of the analyzed plastic bottles were produced in Jamaica, there were also bottles made in neighboring countries, such as the Dominican Republic, Haiti, and Trinidad and Tobago, which are not sold locally. These foreign bottles were likely carried by currents from these countries or improperly disposed of by ships.

Unveiling the risk of marine litter and derelict fishing gear in remote coral reefs of the Andaman and Nicobar Islands, North Indian Ocean

An increasing amount of plastic litter and derelict fishing gear in the global oceans poses significant threats to corals and reef-associated marine biota. In this context, an underwater marine litter survey was conducted along the fringing coral reefs in the Andaman and Nicobar Islands- a remote archipelago in the Bay of Bengal, Northern Indian Ocean. The result revealed entanglement and smothering of coral colonies by plastic and derelict fishing gear. The survey recorded an average litter density of 0.42 ± 0.08 items/m2 (range: 0.23 ± 0.02 to 0.71 ± 0.09) and a mean mass of 138.61 ± 42.15 g/m2 (range: 70.17 ± 7.74 to 303.4 ± 2.55). Plastic was the most dominant litter (60.82 %) recorded in the reef environment. Derelict fishing gear made of plastic comprised 33.65 % of the total litter. Plastic Abundance Index (PAI), Hazardous Item Index (HII), and Clean Environment Index (CEI) were used to assess the ecological impact of marine litter. These indices highlighted the significant risks posed by marine litter to the coral reef environment. The finding helps to strengthen the assessment of marine litter in remote islands and underscores the urgent need for improved waste management, stricter regulations on the disposal of fishing gear, and effective removal of derelict fishing gear from the coral reef environments. Present study offers actionable insights for policymakers and stakeholders to prioritize interventions for managing marine litter to safeguard vulnerable coral reef systems.

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.

Assessment of coastal litter trends in tourist vs. non-tourist beaches: A case study from Indian coastal smart city

Coastal ecosystems are increasingly threatened by the accumulation of marine litter globally. Limited data availability along India's eastern coast hinders targeted mitigation efforts. This study assesses coastal litter along Visakhapatnam, a smart city on India's eastern coast, using the NOAA shoreline debris protocol. Litter assessments at 12 sites before and after the monsoon season revealed high mean litter densities (2.66 ± 0.31 items m-2 before monsoon, 2.03 ± 0.29 items m-2 after monsoon), exceeding the global average by twofold and the national average by five-fold. The tourist beaches saw a 63 % litter reduction after monsoon due to the implementation of better waste management practices, while non-tourist beaches saw a 16 % increase, highlighting disparities in waste management practices. Plastic comprised 86 % of litter, exceeding the global mean proportion (85 %) in marine litter. Alarmingly, 50 % of tourist beaches and all non-tourist beaches were classified as "extremely dirty" by the Clean Coast Index. Land-based influx through stormwater drains was identified as the primary source of litter. This study provides critical baseline data for India's eastern coast, emphasizing the urgent need for targeted interventions, including improved stormwater management and community engagement, to mitigate the escalating marine litter crisis. Further, the findings and recommendations provide valuable insights for managing plastic pollution in coastal cities with similar characteristics, particularly those influenced by monsoons and tourism.

Marine litter along the Peruvian coast: spatiotemporal composition, sources, hazard, and human modification relations

Marine litter (ML) represents an escalating environmental issue, particularly in Latin America, where comprehensive studies are scarce despite critical solid waste management challenges and continuous human modification occurring on the coasts. To contribute to the knowledge of ML in the southeast Pacific, this study examined contamination across 10 beaches on Peru's extensive coast. Overall, ML contamination was categorized as moderate (with an ML concentration of 0.49 ± 0.64 items∙m-2), while significantly differing between summer (dirty with an ML concentration of 0.56 ± 0.66 items∙m-2) and winter (moderate with an ML concentration of 0.47 ± 0.60 items∙m-2). Three beaches were extremely dirty (concentrations of ML exceeded 1.0 items∙m-2). Predominant materials, items, and sources were plastic, cigarette butts (CBs), and mixed packaging. The Peruvian coast faced CB leachate impact (CBPI = 3.5 ± 3.5), reaching severe levels on two beaches, with considerable hazardous litter (HALI = 3.0 ± 2.9). Additionally, a higher degree of human modification was associated with higher ML levels along the coast.

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.

Lost and found: Patterns of marine litter accumulation on the remote Island of Santa Luzia, Cabo Verde

Santa Luzia, an uninhabited island in the archipelago of Cabo Verde, serves as a natural laboratory and important nesting site for loggerhead turtles Carettacaretta. The island constitutes an Integral Natural Reserve and a Marine Protected Area. We assessed marine litter accumulation on sandy beaches of the island and analysed their spatial patterns using two sampling methods: at a fine scale, sand samples from 1 × 1 m squares were collected, identifying debris larger than 1 mm; at a coarse scale, drone surveys were conducted to identify visible marine debris (>25 mm) in aerial images. We sampled six points on three beaches of the island: Achados (three points), Francisca (two points) and Palmo Tostão (one point). Then, we modelled the abundance of marine debris using topographical variables as explanatory factors, derived from digital surface models (DSM). Our findings reveal that the island is a significant repository for marine litter (>84% composed of plastics), with up to 917 plastic items per m2 in the sand samples and a maximum of 38 macro-debris items per m2 in the drone surveys. Plastic fragments dominate, followed by plastic pellets (at the fine-scale approach) and fishing materials (at the coarse-scale approach). We observed that north-facing, higher-elevation beaches accumulate more large marine litter, while slope and elevation affect their spatial distribution within the beach. Achados Beach faces severe marine debris pollution challenges, and the upcoming climate changes could exacerbate this problem.

High levels of anthropogenic litter trapped in a mangrove area under the influence of different uses

The contamination of mangroves by anthropogenic litter has increased in recent decades. Notably, Brazil occupies a prominent status within Latin America, boasting the second-largest mangrove areas globally. In Santos-São Vicente Estuarine System (SESS), mangroves coexist with a preeminent port complex and substantial urbanization rates. Nevertheless, the anthropogenic litter occurrence and distribution in this ecosystem remains unknown. This study aimed to comprehensively assess anthropogenic litter across 13 strategically positioned sites in the SESS. The total litter density (Mean ± SD) was 22.84 ± 36.47 (0.00-142.00) items·m-2, putting the SESS among the top four most contaminated mangrove ecosystems worldwide. Residential zones accumulated more litter than uninhabited areas and significant correlation was seen with human modification index. Plastic was the prevalent material (70.4 %), measuring mostly between 2.5 and 30 cm (41.1 %). It is imperative that local authorities adopt comprehensive strategies to mitigate contamination, while also curtailing the litter inputs to the SSES mangrove ecosystem.

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.

The halophyte Cakile maritima Scop. 1772 as a trap of plastic litter on the Moroccan coast

Some plant communities of coastal dunes may affect the magnitude and distribution of litter on the ecosystem. In this study, the aim is to assess the aptitude of the halophyte Cakile maritima Scop. 1772 to be a trap and sink of plastic litter on the Moroccan Atlantic coast. Overall, a significant difference was noted between plastic litter trapped in C. maritima patches (1173 items) and control plots (502 items). Food containers and ropes were the most common trapped items. Shoreline and recreational activities, followed by dumping and ocean/waterway activities are the main sources of the trapped plastic items. The findings suggest the expansion of the cleaning operations to include coastal dunes, the need to change behavior among beachgoers in regard to food plastics disposal, as well the control of C. maritima distribution in the study area, and similar plant species in other regions.

Beached and Floating Litter Surveys by Unmanned Aerial Vehicles: Operational Analogies and Differences

The abundance of litter pollution in the marine environment has been increasing globally. Remote sensing techniques are valuable tools to advance knowledge on litter abundance, distribution and dynamics. Images collected by Unmanned Aerial Vehicles (UAV, aka drones) are highly efficient to map and monitor local beached (BL) and floating (FL) marine litter items. In this work, the operational insights to carry out both BL and FL surveys using UAVs are detailly described. In particular, flight planning and deployment, along with image products processing and analysis, are reported and compared. Furthermore, analogies and differences between UAV-based BL and FL mapping are discussed, with focus on the challenges related to BL and FL item detection and recognition. Given the efficiency of UAV to map BL and FL, this remote sensing technique can replace traditional methods for litter monitoring, further improving the knowledge of marine litter dynamics in the marine environment. This communication aims at helping researchers in planning and performing optimized drone-based BL and FL surveys.