Litter Density Research Articles

Mangrove litter production in Sei Carang waters of Tanjungpinang City, Riau Island Province

Sei Carang waters are a mangrove ecosystem area with a fairly wide area coverage, Sei Carang waters have mangrove ecosystems. This study aims to determine the level of mangrove density and production of mangrove litter in Sei Carang. This research was conducted May-June 2022 located in Sei Carang. Observation locations were determined by survey methods and point selection using purposive sampling. Then observations using line transects using a plot measuring 10x10 m. There were 6 species found at the study site, namely: Rhizophora apiculata, Rhizophora mucronata, Bruguiera gymnorhiza, Bruguiera sexangula, Sonneratia alba, Xylocarpus granatum. The most common types were found at station 1 where there were 6 of them, and at station 3 there were only 4 types. With density levels ranging from 1633.33 ind/ha to 2300 ind/ha. And also the highest litter production value occurs at station 3 with an average value of 7.21 (gbk/m2) and the lowest occurs at station 2 with an average value of 2.27 (gbk/m2), and the parameters of the Sei Carang waters are still relatively low. good for the life of the mangrove ecosystem when compared to seawater Quality Standards Government Regulation of the Republic of Indonesia No. 22 of 2021 concerning the Implementation of Environmental Protection and Management, Attachment VII.

Are tropical mangroves a sink for litter leaking from land-and sea-based sources? Evidence from selected Kenyan mangroves

Marine litter surveys were carried out to determine the role of mangroves as a sink for litter. General litter density in the mangroves was 0.088 ± 0.076 items m−2, composed mainly of plastic (85.9 %). Higher litter densities occurred in the middle (0.162 ± 0.150 items m−2) compared to the landward (0.066 ± 0.049 items m−2) and the seaward zones (0.036 ± 0.028 items m−2), indicating the important role played by the middle zone in providing a sink for litter from both land and sea-based sources. Landward zones were a sink for heavier litter from land that could easily be trapped by mangrove roots (plastic and clothing). The middle zones retained mainly the litter that are not easily trapped by the mangroves' roots in seaward and landward zones, particularly soft plastics. The seaward zones acted as a sink for litter from sea-based sources mainly marine and fishing gears, and materials used for fishing and boat repairs.

First baseline assessment of seafloor litter on Italian coralligenous assemblages (Mediterranean Sea) in accordance with the European Marine Strategy Framework Directive

A monitoring programme for coralligenous assemblages was carried out in Italy for implementation of the Marine Strategy Framework Directive (MSFD), aiming to characterise the coralligenous' environmental status and litter distribution. A standardised monitoring protocol, based on ROV-imaging, has been applied; this paper analyses the data obtained during the first MSFD cycle (2015–2019). Ninety-five areas were monitored at depths ranging between 14 and 199 m in the three subregions bordering Italy. Overall, 4316 macrolitter items were recorded. The median litter density was 2 items 100 m−2 (range: 0–120 items 100 m−2), but significant subregional differences emerged in litter quantities and composition. Fishery-related litter (mainly lines and ropes) was the most common type (86 %), affecting vulnerable coralligenous reefs. A first baseline is proposed for assessing achievement toward Good Environmental Status and evaluation of the efficacy of the Italian MSFD measures aiming to eliminate the negative effects of marine litter on vulnerable reefs.

General macro-litter as a proxy for fishing lines, hooks and nets entrapping beach-nesting birds: Implications for clean-ups

Fishing lines, hooks and nets represent a sub-category of macro-litter potentially entrapping plover birds nesting on sandy beaches. Here, during a winter period, the accumulation pattern of both general beach litter and fishing lines, hooks and nets was analysed on four central Italy beaches. Despite the active monthly litter removal by clean-ups, there was not a decrease in its density during the winter period, due to the continuous accumulation by frequent winter storms. However, the entrapping litter was very low (<2.5 % of the general litter) and appeared directly correlated to the general litter density. Following a DPSIR approach, the general litter can act as an indirect pressure indicator (proxy) of the amount of entrapping litter. Therefore, an increase in general macro-litter should alarm those involved in the conservation of entanglement-sensitive bird species, such as plovers, suggesting that they should implement high-frequency clean-up activities aimed at removing it.

Breakwaters as habitats for synanthropes: Spatial associations of vertebrates and vegetation with anthropogenic litter

Urban infrastructures can provide ‘novel’ habitats for marine and terrestrial animals and plants, enhancing their ability to adapt to urban environments. In particular, coastal infrastructures characterized by a complex three-dimensional morphology, such as breakwaters, could provide species refuges and food. We investigated the role of breakwaters in providing habitat for vertebrates and plants, and the influence of anthropogenic litter in regulating the value of these structures as habitat. We sampled vertebrate and plant species and quantified the amount of anthropogenic litter on breakwaters and adjacent rocky habitats at several sites in three different countries (Italy, Spain and Chile). We found breakwaters to accumulate more litter items (e.g. especially plastics) than adjacent rocky habitats by means of their large-scale (i.e., 1 m) structural complexity. Birds, which used the artificial infrastructure as transitory habitat, reached similar abundances in breakwaters compared with adjacent rocky platforms. In contrast, synanthropic mammal species, such as Rattus norvegicus and feral cats, were slightly more frequent on breakwaters and appeared to use them as permanent habitat. Plants were frequent in the upper zone of breakwaters and, even though many macrophyte species can trap litter, their cover correlated negatively with anthropogenic litter density. Therefore, breakwaters provide either transitory or permanent habitats for different species, despite functioning as a sink for anthropogenic litter. Thus, new infrastructure should be designed with lower structural complexity in their supralittoral zone limiting the proliferation of synanthropic species. In addition, restricting public access to sensitive areas and enforcing littering fines could enhance the ecological value of these novel habitats by reducing the benefits to pest species.

Assessment of national beach litter composition, sources, and management along the Indian coast - a citizen science approach

The present study evaluates the Pan-India beach litter density (items/m2), weight (kg/m2), composition (%), and probable sources based on the citizen science approach. A total of 33 beaches in 2019 and 30 beaches in 2021 were studied. Based on density, the national beach litter average was 0.475± 0.51 and 0.3 ± 0.4 items/m2 in 2019 and 2021, respectively. Plastic was the dominant litter type (65 % in 2019; 74 % in 2021) and Single-Use Plastics (SUPs) were predominant. Based on Clean-Coast Index, six beaches in 2019 and three beaches in 2021 are classified as “extremely dirty”. The principal (∼60 %) sources of litter were tourism and public littering. Improving solid waste management, stringent implementation of environmental legislation, leveraging the polluter pays principle, monitoring the effectiveness of SUPs ban, generating awareness, and beach clean-up at regular intervals by engaging the public, educational, and non-governmental organizations will improve and sustain the cleanliness of beaches.

A New Monitoring Strategy of Large Micro-, Meso- and Macro-Litter: A Case Study on Sandy Beaches of Baltic Lagoons and Estuaries

Coastal lagoons and estuaries are hot spots to accumulate river basin-related plastic leakage. However, no official methodology exists to investigate their relatively short, rich in organic matter beaches, and the knowledge of pollution of lagoons is scarce worldwide. This study aimed to develop a methodology suitable for large micro (2–5 mm), meso (5–25 mm), and macro-litter (>25 mm) monitoring at sandy inner-coastal waters that would provide comparable results to the intensively used OSPAR 100 m method. The method proposed in this study is based on two 40 m2 rectangular polygons placed on the tidal accumulation zone for macro-litter enumeration and two 1 m2 squares for micro- and meso-litter. This method has been applied to 23 beaches from three inner-coastal waters of the Baltic Sea. This study shows that the litter densities between lagoons and bays differ and depend on the river output intensity and the retention capacity. The “Construction material”, “Plastic pieces 2–5 mm”, and “Plastic pieces 5–25 mm” were among this study’s top ten most common litter items. Experts allocated these items to the “Land based industry and trade” source, which indicates that lagoons and bays through the connection of the major rivers could be a potential sink of land-based litter. An evident strength of the methodology established is the capability to determine litter of all sizes, low-cost and time-efficiency, implementable for volunteer-based monitoring; provides comparable results to the most commonly used methods for investigating litter pollution on coastal beaches.

Temporal considerations for an effective sampling of personal protective equipment litter derived from the COVID-19 pandemic

Personal protective equipment (PPE) has become a new pollutant derived from the COVID-19 pandemic. Much of the efforts to characterize PPE litter has focused on its spatial distribution (i.e., trying to identify hotspots of PPE litter), however, such efforts have been limited in the temporal domain, which might result in under- or overestimations in annual projections. Here, using 55 continuous days of sampling in an urban and tropical neighborhood in south east Mexico, I show that in order to have a robust and defensible average and variance values it is needed at least 22 days of random sampling. Nonetheless, this minimum number might change in different ecosystems and land use areas of the built environment due to the temporal variability of the human behavior and activities related to the surveyed areas, as well as the influence of weather conditions that might affect the mobility of people. Furthermore, I discuss how it is recommended to report the daily average density of PPE litter (items m−2 day−1) and its variability (i.e., 95 % confidence intervals), rather than only the density of PPE litter (items m−2) in order to facilitate annual estimates of PPE litter disposal.

Çanakkale Boğazı Kıyısında Kayalık Bir Alanda Toplanan Deniz Çöplerinin Yıllık Değişimi

Çanakkale Strait is a busy waterway and an important recreational area for the city of Çanakkale frequented by locals and tourists throughout the year. This study was carried out on a constructed coastal rocky area located in the vicinity of the city Center of Çanakkale, between 2021-2022 in order to determine the extent of litter accumulation, type of litter as produced materials and use purposes. A total of 3528 and 1777 items were collected in 2021, and 2022, respectively. Results indicated that litter density was higher than the majority of studies reported from other locations along the Turkish coasts. The most common marine litter was made up of plastics which amounted to 80.24% and 59.65% of total litter composition in 2021 and 2022, respectively. Mixed packing materials were predominant and indicated extensive use of plastic materials in food and beverage sector. Public awareness towards proper ways of litter disposal, use of biodegradable packing materials, beach cleaning and waste management are critical for successful litter management, especially in coastal areas.

A novel beach litter analysis system based on UAV images and Convolutional Neural Networks

Beach litter monitoring programs play a key role in establishing effective management measures to preserve the ecological, scenic, and economic value of the coastal areas. In this study, an innovative analysis system is proposed for the automatic identification of beach debris (>2.5 cm) on aerial-photogrammetric images acquired by unmanned aerial vehicles (UAV) at different elevations. The workflow is based on a Convolutional Neural Network model designed for object segmentation and object recognition, and here used for instance segmentation tasks. Test cases were conducted along the Adriatic sector of the Apulia region (Italy), where the beaches have a remarkable economic importance, attracting national and international tourists, and ecological values, hosting species of high ecological value and protected areas. The results of the tests carried out in this study allowed defining 10 m as the desirable drone flight above ground. In addition, encouraging results have been obtained on the instance segmentation step, experimenting on real, synthetic and mixed data, produced by using a high-resolution blending technique. A beach litter density of 0.38 items m−2 (on 0.66 items m−2), an F-score of 0.96 and a mAP of 0.67 has been achieved on real data. A novel metric for comparing works at the state-of-the-art (SOTA) in beach litter monitoring is also introduced, named “density-normalized F-score”. The proposed methodology represents a benchmark for the definition of a standardize procedure for the indirect evaluation and monitoring of the coastal environmental status. Besides allowing the investigation of large areas with limited human effort, the proposed system enables the evaluation of the beach litter spatial distribution and magnitude, providing useful information for the assessment of tailored beach quality indices.

Unraveling Macroplastic Pollution in Rural and Urban Beaches in Sarangani Bay Protected Seascape, Mindanao, Philippines

Plastic pollution in the ocean is an emerging environmental concern in the Philippines. This study was conducted to investigate the prevalence of macroplastics, composition of plastic litter, and the clean-coast index (CCI) of urban and rural beaches in Sarangani Bay. Plastic litter was collected by delineating a 100-m transecting line with three 4 m × 4 m quadrats. The density of macroplastic litter in urban areas (0.66 items m−2) was significantly higher than in rural areas (0.29 items m−2). The plastics sampled were predominantly food packaging, such as polyethylene bags, which are locally known as sando bags. The accumulation rate of macroplastic litter ranged from 0.07 items d−1 m−2 to 0.40 items d−1 m−2, in which urban beaches (0.25 items d−1 m−2) have a significantly higher accumulation rate than rural beaches (0.11 items d−1 m−2). Overall, the calculated CCI of the beaches of Sarangani Bay was categorized as clean to moderately clean for rural beaches and moderately clean to extremely dirty for urban beaches.

Impact of the COVID-19 pandemic on coastal environment: positive or negative? A 1-year study on litter in Caspian coasts

Litter is one of the major environmental problems. These wastes cause adverse health, environmental, and even economic effects. One of the consequences of the COVID-19 pandemic is the impact on litter composition and density due to its changes in lifestyle and consumption patterns. In this study, the effect of the COVID-19 pandemic on the composition and density of litter on the ten southern beaches of the Caspian Sea in Iran in 1 year was investigated. The results showed that the density of the litters was in the range of 36.5–306 items/m2. The highest and lowest proportions of the COVID-related litters on the locations studied were 2.54 and 5.95%, respectively. The indexes in the areas studied showed that the COVID-19 pandemic has reduced the density of the litter in 90% of the beaches studied by changing the style of citizens, but the emergence of new dumping related to COVID-19 has increased the potential for health and environmental hazards caused by litters. The effects of the COVID-related litters increased the clean environment index by 5 to 12% on the beaches. This study shows that the impact of social phenomena such as a pandemic on litter and its results can be used for the better management of municipal solid wastes, including litter in similar situations in the future.

Role of Citizen Scientists in Environmental Plastic Litter Research—A Systematic Review

In recent years, citizen science has proven to be an effective means of monitoring plastic litter, bring potential benefits to professional researchers and authorities, and create awareness on plastic pollution at a society level. This paper aims to review the advances of employing the citizen science approach for plastic litter evaluation and explore the research contributions of these initiatives and their impact at the society and environmental levels. A systematic search was undertaken using the main scientific paper databases and back-referencing from reviewed papers over a period of 10 years. Out of 221 papers found, only 94 papers that discussed plastic litter/waste and citizen science remained in the analysis. Geographically, 66% of the studies were concentrated in the Northern Hemisphere (mostly in USA). The majority were related to clean-up activities that analysed litter density, types, and potential sources. The results showed that citizens can provide data over large geographical regions and can be essential to researchers and authorities in implementing litter management policies. Citizen science programs are effective in creating awareness and increasing education regarding plastic litter pollution and impact. However, it is not clear if they can enhance behavioural changes after participation in field survey programs.

Litter, Plant Competition, and Ecosystem Dynamics: A Theoretical Perspective.

AbstractCommunity structure depends jointly on species' responses to, and effects on, environmental factors. Many such factors, including detritus, are studied in ecosystem ecology. Detritus in terrestrial ecosystems is dominated by plant litter (nonliving organic material), which, in addition to its role in material cycling, can act as a niche factor modulating interactions among plants. Litter thus links traditional community and ecosystem processes, which are often studied separately. We explore this connection using population dynamics models of two plant species and a litter pool. We first find conditions determining the outcome of interactions between these species, highlighting the role that litter plays and the role of broader ecosystem parameters, such as decomposition rate. Species trade-offs in tolerance to direct competition and litter-based interference competition allow for coexistence, provided the litter-tolerant species produces more litter at the population level; otherwise, priority effects may result. When species coexist, litter-mediated interactions between plants disrupt the traditional relationship between biomass accumulation and decomposition. Increasing decomposition rate may have no effect on standing litter density and, in some cases, may even increase litter load. These results illustrate how ecosystem variables can influence community outcomes that then feed back to influence the ecosystem.

Marine litter in submarine canyons: A systematic review and critical synthesis

The presence of marine litter is of concern in submarine canyons, although research in this area is still in its infancy. A critical synthesis and literature review selecting studies with primary data of benthic marine litter at depths of over 50 m revealed important gaps in the knowledge, with information on the impact of macroplastics in deep-sea environments still scarce. Less than 1% of medium to large submarine canyons mapped have been studied in any measure for marine litter, with over 91% of the canyon studies located in European waters. Imaging techniques are now the main tools used for sampling, overtaking trawling methods despite the continued growth of the latter for marine litter deep-sea research. Enumeration of litter was diverse with over 75% using abundance for quantification. Despite the existence of litter protocols available for deep-sea environments, over 73% of studies did not use any. There was no standardization in the implementation of established classification protocols, which were either not used in full or were customized in part. Fishing-related categories do not feature as a top-level category in the classification hierarchy in any of the protocols, yet over 50% of publications featured fishing materials as a main category, pointing to a more intuitive activity-based categorization of litter instead of a materials-led approach from the established protocols. Furthermore, interactions between litter and the surrounding environment and biota are very much underreported with little or no consensus between how the data are analyzed and expressed. There were no discernible patterns between litter density, composition and broad geographical location of canyons, with individual topographical characteristics, hydrodynamic regimes and anthropogenic activities being determining factors in how submarine canyons are affected by litter. Overall, there is no apparent framework to allow comparison of studies and due to the different methods of identifying, enumerating, quantifying and classifying marine litter, or lack of data on position and morphological setting within the canyon system. The evidence provided within this study highlights a ‘call to action’ for an urgent need to standardize and unify methodologies with new or established protocols to fully understand the impact of marine litter in submarine canyons.

Floating marine macro litter in the Black Sea: Toward baselines for large scale assessment

The Black Sea is a semi-enclosed basin subject to major anthropogenic pressures, including marine litter and plastic pollution. Due to numerous large rivers draining into the basin and a population settled along the coast, the region could accumulate significant amounts of floating litter over time. Until now, only limited field data were available, and litter quantities and distribution remained unknown. In this study, floating marine macro litter (FMML) was assessed at the regional Black Sea scale for the first time, showing relatively high litter densities across the basin that reached a weighted mean of 81.5 items/km2. Monitoring data revealed an accumulation of floating items offshore in the eastern part of the basin, resembling on a small scale a ‘garbage patch’, where litter items were trapped, showing elevated densities in comparison to their surrounding areas. Most of these items were made of plastic materials (ca. 96%) and included large numbers of plastic and polystyrene fragments of small size ranges (2.5–10 cm). Harmonised field data collection through consistent and regular monitoring programmes across the region is essential to establish baselines and thresholds for large scale assessment at international level.

Marmara Denizi’nde bentik deniz çöpü

This study presents the first data on benthic marine litter in the Marmara Sea, Turkey. To obtain the data, bottom trawl surveys were conducted at 34 sites between May 2017 and February 2018. The litter items were sampled and sorted following the MEDITS’ relevant instructions. 660 pieces of litter, weighing 434.9 kg, were sampled. The litter density was found to range between 27.5 n/km2 and 661.2 n/km2, averaging 73.9 n/km2, and the obtained items’ weights ranged between 0.03 kg/km2 and 1597.8 kg/km2, averaging 48.7 kg/km2. The plastic group L1 constituted 71.7% of the trawled litter. The highest mean litter density was detected in the Northeastern Marmara Sea in the spring and summer of 2018. The mean benthic litter density was found to be higher than the nearby areas. It was concluded that more effort should be invested in reducing marine pollution.

Accumulation of marine litter in cold-water coral habitats: A comparative study of two Irish Special Areas of Conservation, NE Atlantic

Cold-water corals (CWCs) have come under threat from anthropogenic activities such as fishing despite their ecological significance as biodiversity hotspots and as such are being protected in Europe under the EU Habitats Directive with some designated as Special Areas of Conservation (SACs). This study maps the distribution and sources of marine litter in CWC habitats in two SACs on the Irish margin. Data were collected with remotely operated vehicle in the SACs. The density, abundance and composition of litter were assessed, with differences observed between the two sites. The regional morphology influences the distribution of litter in the SACs, with CWC reefs and rock exposures trapping more marine litter. Fishing gear (80.7%) and plastics (55.1%) were commonly found. The observed fisheries-derived litter in the SACs exceed global averages of 10–20% fishing gear, suggesting the SACs appear to offer limited protection to the coral habitats with respect to marine litter.

Role of protected area in reducing marine and plastic litter: A case study from India's first Marine Protected Area and comparison with Non‐Protected Areas

AbstractThis research is the first to assess marine litter and plastic pollution in India's first marine protected area (MPA), the Gulf of Kachchh Marine Protected Area (GOKMPA). We compare it to two non‐protected areas, that is, Okha Beach and Beyt Dwarka, known for their high industrial and tourist activity, respectively. Standing‐stock surveys were used to collect primary litter data, while questionnaire surveys were used to learn about people's perception and attitude towards the plastic pollution problem in the study area. We found that plastic was the most common component of the litter at all the sites and that it was primarily of terrestrial origin. Compared to non‐protected sites, GOKMPA had the lowest litter density but the highest proportion of plastic litter. Single‐use plastic bottles were the most counted items at all the sites, regardless of the conservation status of the sites. The majority of people (locals, visitors, and fishers) around these sites expressed concern about waste but were hesitant to take responsibility and discourage or prevent littering. We noted that designating coastal territories as protected areas helps in reducing plastic pollution while also conserving habitat and biodiversity. However, this could change rapidly due to either mishandling of litter within MPAs or neighboring non‐PAs, and also because plastics pose an actual toxicity risk when present even at minimal concentrations in the environment. We recommend combining preventive, mitigating, and curative measures in areas where risk hotspots for plastic litter are identified, and such sites must be constantly monitored. Long‐term solutions could include transitioning from a linear to a circular economy, which would involve goals for reducing plastic waste and instituting more sustainable production and consumption patterns.

Rapid Characterization of Macroplastic Input and Leakage in the Ganges River Basin.

Efforts to understand macroplastic pollution have primarily focused on coastal and marine environments to the exclusion of freshwater, terrestrial, and urban ecosystems. To better understand macroplastics in the environment and their sources, a dual approach examining plastic input and leakage can be used. In this study, litter aggregation pathways at 40 survey sites with varying ambient population counts in the Ganges River Basin were surveyed in pre- and postmonsoon seasons. We examine active litter leakage using transect surveys of on-the-ground items, in conjunction with assessments of single-use plastic consumer products at the point of sale. We find that sites with low populations have a significantly higher number of littered items per 1,000 people than those with mid to high populations. Over 75% of litter items were plastics or multimaterial items containing plastic, and tobacco products and plastic food wrappers were the most recorded items. There was no significant variation of litter densities pre- and postmonsoon. Most single-use plastic consumer products were manufactured in-country, but approximately 40% of brands were owned by international companies. Stratified sampling of active litter input and consumer products provides a rapid, replicable snapshot of plastic use and leakage.