The spatial and temporal changes of beach litter on Istanbul (Turkey) beaches as measured by the clean-coast index

Coastal beach ecosystems contaminated by marine litter: Impact on coastal biodiversity, tourism, and environmental sustainability

This study examined the abundance, composition, sources, and pollution status of marine macro litter (>2.5 cm) at four beaches in Sri Lanka (Kallady, Negombo, Kandakuliya, and Balapitiya), located along the coastline of the northern Indian Ocean. Clean Coast Index (CCI), Plastic Abundance Index (PAI), Hazardous Item Index (HII), and Environmental Status Index (ESI) were used to evaluate the pollution levels. A total of 10,873 litter items were collected from four beaches representing 11 typologies. The average density of the litter collected was 0.7-1.2 items/m2. Plastic items constituted the majority of litter found, with a percentage of 51%. Kallady Beach was classified as "extremely dirty," while the others were rated as "dirty" according to the CCI. All beaches fell under category "II" on the HII. PAI indicated high and moderate plastic contamination, and the ESI classified all sites as having a "bad" environmental status. The majority of litter originated from land-based sources, including unsustainable fishing practices, poor waste management, and harmful recreational activities. The findings highlight the urgent need for comprehensive marine and coastal management frameworks to address these challenges. Despite existing awareness and cleanup efforts, the study calls for innovative waste management solutions, enhanced regulations, corporate responsibility, and further research to protect Sri Lanka's coastal ecosystems. These effective management steps are essential to mitigate marine litter and ensure the long-term health of these sensitive ecosystems.

An analysis of human impact on sandy coasts of the Costa Rican Pacific

Increased human activities on sandy beaches have significantly impacted ecosystems. This study aims to determine whether beaches with higher tourism and human activities exhibit greater impact on various ecological indicators compared to less-visited beaches. Ecological monitoring was performed across three sandy beaches, where sand samples were collected during three visits. Sediment characteristics, macrofauna presence, crab burrows abundance, and solid waste were analyzed. Fourteen benthic macrofauna taxa, 1209 crab burrows, and 7645 intertidal organisms were recorded. Notably, 98.8 % of the solid waste consisted of plastic items. Differences in organic matter, carbonates, the number of crab burrows, and macrofauna were observed, indicating that increased tourism and human activity influence these ecological indicators. These findings represent an initial step toward more rapid and comprehensive ecological monitoring of beaches, contributing to coastal environmental management and decision-making.

Mesoplastics: A Review of Contamination Status, Analytical Methods, Pollution Sources, Potential Risks, and Future Perspectives of an Emerging Global Environmental Pollutant

Mesoplastics are emerging environmental pollutants that can pose a threat to the environment. Researching mesoplastics is crucial as they bridge the gap between macroplastics and microplastics by determining their role in plastic fragmentation and pathways, as well as their ecological impact. Investigating mesoplastic sources will help develop targeted policies and mitigation strategies to address plastic pollution. These pollutants are found across aquatic, terrestrial, and agricultural ecosystems. Unlike microplastics, mesoplastics are reviewed in the scientific literature. This paper focuses on existing published research on mesoplastics, determining the trends and synthesizing key findings related to mesoplastic pollution. Research primarily focused on marine and freshwater ecosystems, with surface water and beach sediments being the most studied compartments. Mesoplastics research often offers baseline data, with increased publications from 2014 to 2024, particularly in East Asia. However, certain ecosystems and regions remain underrepresented. Also, mesoplastics can disrupt ecosystems by degrading biodiversity, contaminating soils and waters, and affecting food chains. Mesoplastics can also become vectors for additives and pathogenic microorganisms, highlighting their environmental risks. Various factors influence mesoplastics' prevalence, including anthropogenic and non-anthropogenic activities. With this, future research should expand into less-studied ecosystems and regions, explore mesoplastic interactions with pollutants and organisms, and promote public awareness, education, and policy measures to reduce plastic use and mitigate pollution globally.

Investigating macro marine litter and beach cleanliness along Southern Vietnam beaches

Plastic contamination is a major issue for marine ecosystems, with macro-litter posing a growing threat globally. This study assesses macro-marine litter on Vung Tau beaches, Southern Vietnam, providing baseline data for marine litter pollution and identifying critical action plans for plastic control. Survey results showed litter density ranging from 0.1768 to 0.4464 items m-2 across twelve sites. Using the Clean Coast Index (CCI), 16.7 % of beaches were rated as "Clean" and 83.3 % as "Moderate," while the Plastic Abundance Index (PAI) revealed 91.7 % of sites had "Moderate" plastic levels. Human activities, such as tourism and insufficient waste management, were key contributors. Addressing this issue requires raising awareness, promoting behavioural change and tourist perceptions, and enhancing waste management efforts. Prioritizing marine protection programs is crucial for effectively eliminating marine litter and plastic waste.

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.

Carbonyl index of miniaturized microplastics at the sea surface

We investigated the carbonyl index (CI) of small microplastics (SMPs; 50-350 μm) and large microplastics (LMPs; >350 μm) in the surface waters of the Tokai region and Tokyo Bay in Japan. The degradation was evaluated by determining the CI from the infrared spectrum of microplastics (MPs) adopting the specified area under the band technique. Average CIs of SMPs and LMPs in polyethylene were 2.47 and 0.67 off Tokai and 2.71 and 0.76 in Tokyo Bay, respectively. No significant differences in the CI were found between polyethylene and polypropylene. However, significant differences in CIs were found between SMPs and LMPs. The relationship between the major length of MPs and CI was significantly negative for both polyethylene and polypropylene (p < 0.05). The results indicate that as MPs degrade, they become finer and exhibit a higher CI at the sea surface.

Assessment of transboundary macro-litter on the remote island of Andaman and Nicobar: Unveiling the governing factors and risk assessment

The increasing occurrence of mismanaged plastic litter along India's coastline and the ominous challenges it poses to biodiversity and ecosystem health is a growing environmental concern. To address this issue, we comprehensively investigated the abundance, composition, and probable sources of marine litter on North Cinque Island, a remote uninhabited island in the Andaman and Nicobar archipelago, Bay of Bengal. This island is a designated wildlife sanctuary and serves as an important nesting site for Green, Hawksbill and Leatherback turtles. A total of 6227 litter items were enumerated, with an average concentration of 0.12 items/m2, representing 20 diverse litter types, with plastic dominating the litter composition (86 %). The cleanliness and environmental hazards of the coast due to the litter were assessed using different indices such as the Clean Coast Index (CCI), Plastic Accumulation Index (PAI), Hazardous Item Index (HII), and Clean Environment Index (CEI). CCI indicates the moderately clean-to-clean status of the surveyed sites. PAI points to low to moderate accumulation of plastic litter. HII of all five coasts fell in category II, suggesting a moderate abundance of hazardous items that can inflict injuries to the foraging turtle and their hatchlings. The CEI articulates the moderately clean to very clean status of the sites. Litter brand audit suggests a considerable amount of stranded litter on the coasts was transboundary and originated from six Indian Ocean Rim Countries (IORC), namely Thailand, Myanmar, Malaysia, Indonesia, Sri Lanka, and UAE. Joint solid waste management by the IORC is the need of the hour to avert litter accumulation on the pristine, remote islands.

Study of pollution status in urban environment caused by attitude and waste littering behavior of citizens

Littering behavior is one of the main challenges in waste management, especially in big cities. In this study, density and composition of litter in Tehran was investigated and the urban pollution status was calculated by using the clean environment index. The results showed that the average density of litter in the studied locations was 0.182 number/m2. Spatial variation in the litter density showed that the average density in commercial and residential land-uses was 0.22 and 0.14 number/m2, respectively. Cigarette butts (29%), bottle caps (18%), and paper receipts (10%) consisted the largest ratio of the litter composition in the studied locations. Clean environment index for the studied locations was calculated in the range of 2.34 to 10.42. Based on this, 30% of the studied locations were in a clean status and 70% were in a polluted and worse status. The litter density in the city, interviews with citizens, and the results of previous studies showed insufficient awareness of citizens about the consequences of littering in the urban environment, which led to the prevalence of littering behavior. So, the littering behavior by citizens has caused the urban environment pollution and increased health risk. Educating citizens and modifying their behavior to avoid littering is necessary to improve the observed status.

The first assessment of marine litter on somalian coast: The case of Liido Beach, mogadishu

This paper presents the first assessment of marine litter in the Mogadishu coastal area of Somalia. Samples were collected monthly using 100 m × 40 m transect and classified following OSPAR Marine Litter Survey Guide while litter sources were identified using Ocean Conservancy Marine Debris Index. The results showed a total of 119873 items consisting of plastics (89.47%), clothing items (7.53%), and others (3.00%) recovered from Liido Beach. Litter density ranged from 2.19 items/m2 to 14.18 items/m2 with a mean of 6.25 items/m2 and Clean Coast Index (CCI) suggesting that Liido Beach is extremely dirty (>20 items/m2). In addition, the primary sources of marine litter at the beach are local recreational and shoreline activities (54.12%), and dumping (36.61%). The dominance of plastic litter on the beach poses potential threats to marine biodiversity in the Somalia coastal area and the West Indian Ocean. It is recommended that effective strategies and solutions to mitigate litter on the beach and other coastal areas in Somalia should be developed and compensated with public education and awareness campaigns across the country.

A comparative study of indexes used for litter pollution assessment in urban and public environments

Litter is a common pollution in the urban environment and public places such as beaches, which has serious health and economic consequences. Several indexes are used to interpret the pollution status caused by litter, which have different limitations and strengths. In this review, the efficiency and characteristics of different indexes were compared. For this purpose, related articles were searched in Scopus, PubMed, and Web of Knowledge, and after screening, 21 articles were selected. The main questions of this study included factors affecting the interpretation of pollution in different indexes and the criteria considered in each index. The results showed that the existing indexes based on the type of litter include two categories of comprehensive indexes such as Clean Environment Index and specific indexes such as Cigarette Butt Pollution Index. Also, the index can be divided into two categories in terms of spatial application, including general indexes such as Environmental Status and specific indexes such as Clean Coast Index. An important difference in the indexes is the importance of the impact of the pollution potential of different litter in the assessment of the status in indexes such as Clean Environment Index and Environmental Status, while indexes such as Clean Coast Index evaluate the status based only on the density of litter. According to the capabilities of each of the indexes, it is necessary to pay attention to the local needs as well as the characteristics of each index in using in urban management plans.

Accessing the intrinsic factors of carbonyl index of microplastics: Physical and spectral properties, baseline correction, calculation methods, and their interdependence

Carbonyl index (CI) is a measure of the degradation status of microplastics. While many studies address environmental factors of microplastic degradation, intrinsic factors like physical properties, spectral properties, baseline correction, and CI calculation methods are less explored. This research focused on these aspects using surface seawater samples. We found that color and shape have limited dependence on particle size or signal-to-noise ratio (SNR). Baseline correction can significantly alter CI values, with the direction of the shift depending on the methods used. Additionally, most CI values before and after baseline correction and those calculated using different methods tend to be strongly correlated. Using the selected CI calculation methods, we found that CI values varied significantly by shape and color. CI's relation to the similarity between the sample and its pristine form suggests an alternative degradation measure. Our findings emphasize the need for standardized CI calculation methods.

The new era hypothesis of coastal degradation: G(s) elements-gallium, gadolinium, and germanium

Mining of precious metals contributes to environmental pollution, especially in coastal areas, and conventional treatment methods are not always effective in removing metal contaminants. Some of these metals, such as gadolinium, germanium and gallium, have caused increasing concern worldwide, as little is known about their current concentrations in the aquatic environment and their biological significance. Therefore, the aim of this study was to determine for the first time the variation of average G(s) concentrations (gallium, gadolinium and germanium) by month/season/site differences along the coast of Istanbul. The ecological risk index was calculated to assess the contamination of seawater and to serve as a diagnostic tool for the mitigation of water pollution. The average distribution G(s) in seawater was in the following order: Ga > Gd > Ge. In addition, the potential ecological risk in the sampling areas ranged from 68 to 1049. Of the three metals, Gd poses the highest ecological risk (grade III). In the spatial distribution of ecological risks, Gd mainly originated from discharges from wastewater treatment plants. Therefore, the sources of the anthropogenic Gd anomaly in wastewater should be identified, as this indicates the possibility of human exposure to potentially harmful anthropogenic compounds.

Investigation of two different size microplastic degradation ability of thermophilic bacteria using polyethylene polymers

There are several studies stating that many types of microplastics cannot be retained completely by conventional wastewater treatment systems. Therefore, it is necessary to prevent the discharge of these microplastics to the ecological system. The objective of this study was to investigate the biodegradation ability of two different size of PE (50 and 150 µm) by using two Gram-positive, spore-forming, rod-shaped, and motile thermophilic bacteria, called strain Gecek4 and strain ST5, which can hydrolyse starch, were isolated from the soil's samples of Gecek and Ömer hot-springs in Afyonkarahisar, Turkey, respectively. Phenotypic features and 16S rRNA analyzing of strains also studied. According to these results, Gecek4s and ST5 were identified as Anoxybacillus flavithermus Gecek4s and Bacillus firmus ST5, respectively. Results showed that A. flavithermus Gecek4s could colonise the polymer surface and cause surface damage whereas B. firmus ST5 could not degrade bigger-sized particles efficiently. In addition, morphological changes on microplastic surface were investigated by scanning electron microscopy (SEM) where dimensional changes, irregularities, crack, and/or holes were detected. This finding suggests that there is a high potential to develop an effective integrated method for plastic bags degradation by extracellular enzymes from bacteria.

Plastic pollution on remote islands: A baseline study of Príncipe, Gulf of Guinea

Plastic is the most abundant marine anthropogenic debris in the ocean and is of serious global environmental concern. Projects aimed at monitoring plastic pollution quantities are key in evaluating the success of reduction. This study provides baseline information on the quantities of marine debris found on the island of Príncipe in the Gulf of Guinea in the Atlantic coast of Central Africa. A total of 13,196 items were collected with 64.5% of these items being plastic. Plastic pieces the size of 2.5-50 cm made up 20.8% of all plastic items, followed by plastic bags (13.3%) and fishing material (11.39%). The density of mesoplastic items (<25 and >5mm) ranged between 0 and 6.78 items m-2. Beach location, community presence, and beach level (for turtle-nesting beaches) were important factors in explaining differences in plastic abundance and density around the island. Our results highlight the significance of high plastic pollution accumulation on remote islands.

Challenges of Raman spectra to estimate carbonyl index of microplastics: A case study with environmental samples from sea surface

This study investigates the feasibility of using the carbonyl index (CI) derived from Raman spectra as an indicator of plastic degradation and its relationship with the CI calculated from Fourier transform infrared (FTIR) spectra, using microplastic samples of polyethylene (PE) from surface seawater. Multiple methods were used to calculate the CI values of FTIR spectra, while proposed methods were used to calculate the corresponding CI values of Raman spectra. Some significant relations between FTIR CI and Raman CI were observed. However, small R2 values suggest weak functional relationships, which can be attributed to the low signal-to-noise ratio (SNR) of Raman spectra. These results highlight the challenges of establishing a functional relationship between FTIR CI and Raman CI, including challenges such as the uniformity of Raman spectra, determining optimal Raman measurement parameters, selecting appropriate peaks for Raman CI calculation, deciding on spectral processing methods, and addressing the interdependence of these issues.

Impact of coastal wastewater treatment plants on microplastic pollution in surface seawater and ecological risk assessment

This study aims to understand the influence of wastewater treatment plant discharge on the microplastic status in the surface seawater of Istanbul. For this purpose, for the first time, the distribution, composition, and ecological risk of microplastics at nine sampling stations on the southern coast of Istanbul, Marmara, were investigated at monthly intervals over a one-year period. The results showed that the microplastic abundance ranged from 0 to over 1000 particles per liter. Fibers were the dominant form at all stations. Microplastics 249-100 μm were the dominant size, and transparency was the color most found at all stations. Polyethylene and ethylene-vinyl acetate were the major types of microplastics, accounting for 50% overall. The pollution load index revealed that over 70% of sampling stations were at hazard level I. However, the hazardous index was categorized as level III with a value of 662.3 due to the presence of the most hazardous polymer named polyurethane. Further investigations into the risk assessment of MP can reveal crucial knowledge for understanding the microplastic cycle.

Identification and quantification of additive-derived chemicals in beached micro-mesoplastics and macroplastics

Although marine plastic debris are expected to retain various chemical additives, little is known about the additives that are retained. We conducted a screening analysis of additives in 261 macroplastic and micro-mesoplastic debris from two beaches. We detected 52 chemicals-antioxidants, phthalates, ultraviolet stabilizers, hindered amine light stabilizers, and flame retardants-and quantified the concentrations of 15 of them. Comparison of the concentrations of Irgafos 168, an antioxidant stabilizer, among sample categories indicated that leaching had occurred from micro-mesoplastics. Differences in diffusion rates between polymer types may explain faster leaching from polyethylene than polypropylene. The significant amounts of Irgafos 168 retained in even micro-mesoplastics indicated the importance of plastics as a vector of additives. This study provides fundamental data needed to assess the risks to organisms from exposure to plastic additives and to understand the effect of stabilizers on the aging behavior of marine plastics.

Marine litter on the beaches of the Kanyakumari, Southern India: An assessment of their abundance and pollution indices

The problem of marine litter is increasing along the Indian coast. For conducting a baseline study to identify and assess the abundance, clean-coast index (CCI), and plastics abundance index (PAI) of marine litter were calculated on the beaches of Kanyakumari, Southern India. A total of 11,439 marine litter items were collected and classified into 33 groups along the 7 beaches of Kanyakumari. From the results, plastics were the most abundant items (65.08 %) followed by foam (21.93 %), along with cloths (4.59 %), rubber (3.09 %), papers (2.26 %), glass (2.16 %), metal (0.38 %), wood (0.26 %), and others (0.26 %). The average CCI value (27.24) indicates that all beaches are 'extremely dirty'; however, the PAI average value (4.37) indicates 'high abundance'. About 96.87 % of the marine litter originates from the land-based sources. This study provides an interpretive framework for further plastic pollution assessment, which could lead to a better marine litter management on Indian beaches.

Isolation of Thermophilic Bacteria and Investigation of Their Microplastic Degradation Ability Using Polyethylene Polymers

Microplastics (MPs) pose potential public health challenges because of their widespread occurrences in all environmental compartments. While most studies have focused on the occurrence fate of microplastics in wastewater treatment systems, the biodegradation of microplastics in wastewater is generally little understood. Therefore, we used two Gram-positive and thermophilic bacteria, called strain ST3 and ST6, which were identified by morphological, biochemical, physiological, and molecular analyses, to assess the growth and biodegradation potential of two different sized (50 and 150 m) polyethylene particles. The degradation was monitored based on structural and surface morphological changes. According to 16S rRNA analyses, ST3 and ST6 were identified as Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6, respectively. The occurrence of cracks, holes, and dimensional changes was detected by scanning electron microscopy. Moreover, critical characteristic absorption band formation and modifications were determined by Fourier transform infrared spectroscopy. In addition to these, it was found that Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6 produced high level of alpha-Amylase. These results showed that thermophilic bacteria are capable of the biodegradation of microplastics and production of alpha-Amylase.

Beach litter contamination of the Turkish middle Black Sea coasts: Spatial and temporal variation, composition, and possible sources

Marine litter is one of the biggest environmental problems nowadays. Sinop, is located in the heart of Türkiye's Black Sea coast, has a small population, and is a popular fishing and tourist destination. In this study, marine litter amount, composition, and possible sources were investigated, and seasonal comparisons were made between in Sinop beaches. Marine litter amount was found as 0.29-7.67 items·m^-2 and 3.46-49.09 g·m^-2 and beaches were classified as moderate to extremely dirty. Plastics were the highest ratio (88.14-98.46 %) and "plastic pieces 2.5> <50 cm" were the major litter type. The major possible litter source was improper waste disposal (33.36 %) and litter items originated from mainly land-based sources (74.13 %). The result of this study shows that there is a significant litter problem on the coasts. The solution of this problem can be possible to take rational measures against marine litter pollution with education and management policies.

Spatio-temporal variation and seasonal dynamics of stranded beach anthropogenic debris on Indonesian beach from the results of nationwide monitoring

The first stranded macrodebris study on a national scale in Indonesia was conducted on 18 beaches from February 2018 to December 2019. The average weight and abundance of beach debris were higher between October and February (rainy season). The highest stranded macrodebris was located in Ambon, Manado, Takalar, and Padang. Plastic (46.38 %) was the most prevalent type of debris across all macrodebris categories, with single-use plastics such as plastic sachets, plastic bags, and plastic bottles being the dominant macroplastic debris (64.64 %). Based on CCI, HII, and BGI, 18 beaches are "moderately clean," with few hazardous items observed, and "Good." This anthropogenic macrodebris is thought to be more localized (55 %) than transboundary macrodebris. Litter control and environmental quality of this Indonesian coastal region should be improved through a proactive and flexible approach. Finally, extensive stranded beach debris monitoring is recommended to better understand the distribution of macrodebris in the region.