Estimates of marine debris accumulation on beaches are strongly affected by the temporal scale of sampling

Predictive modelling reveals Australian continental risk hotspots for marine debris interactions with key threatened species

Anthropogenic debris is a global threat that impacts threatened species through various lethal and sub-lethal consequences, as well as overall ecosystem health. This study used a database of over 24,000 beach surveys of marine debris collated by the Australian Marine Debris Initiative from 2012 to 2021, with two key objectives: (1) identify variables that most influence the occurrence of debris hotspots on a continental scale and (2) use these findings to identify likely hotspots of interaction between threatened species and marine debris. The number of particles found in each beach survey was modelled alongside fifteen biological, social, and physical spatial variables including land use, physical oceanography, population, rainfall, distance to waste facilities, ports, and mangroves to identify the significant drivers of debris deposition. The model of best fit for predicting debris particle abundance was calculated using a generalized additive model. Overall, debris was more abundant at sites near catchments with high annual rainfall (mm), intensive land use (km2), and that were nearer to ports (km) and mangroves (km). These results support previous studies which state that mangroves are a significant sink for marine debris, and that large ports and urbanized catchments are significant sources for marine debris. We illustrate the applicability of these models by quantifying significant overlap between debris hotspots and the distributions for four internationally listed threatened species that exhibit debris interactions; green turtle (26,868 km2), dugong (16,164 km2), Australian sea lion (2903 km2) and Flesh-footed Shearwater (2413 km2). This equates to less than 1% (Flesh-footed Shearwater, Australian sea lion), over 2% (green sea turtle) and over 5% (dugong) of their habitat being identified as areas of high risk for marine debris interactions. The results of this study hold practical value, informing decision-making processes, managing debris pollution at continental scales, as well as identifying gaps in species monitoring.

Daily accumulation rates of floating debris and attached biota on continental and oceanic island shores in the SE Pacific: testing predictions based on global models

Background

Long-distance rafting on anthropogenic marine debris (AMD) is thought to have a significant impact on global marine biogeography and the dispersal of non-indigenous species. Therefore, early identification of arrival sites of AMD and its epibionts is crucial for the prioritization of preventive measures. As accumulation patterns along global coastlines are largely unstudied, we tested if existing oceanographic models and knowledge about upstream sources of litter and epibionts can be used as a simple and cost-efficient approach for predicting probable arrival sites of AMD-rafting biota in coastal zones.

Methods

Using the Southeast Pacific as a model system, we studied daily accumulation rates, composition, and minimum floating times of AMD with and without epibionts on seven sandy beaches, covering the oceanic environment (Rapa Nui/Easter Island) and three regions (south, centre, north) along the Chilean continental coast, over a minimum of 10 consecutive days, and we contrast our results with predictions from published models.

Results

Total AMD accumulation rates varied from 56 ± 36 (mean ± standard deviation) to 388 ± 433 items km^-1 d^-1 and differed strongly between regions, in accordance with local geomorphology and socioeconomic conditions (presence of larger cities and rivers upstream, main economic activities, etc.). Daily accumulation of items with pelagic epibionts (indicators of a pelagic trajectory) ranged from 46 ± 29 (Rapa Nui) to 0.0 items km^-1 d^-1 (northern continental region). Minimum floating times of rafts, as estimated from the size of pelagic epibionts, were longest in the South Pacific Subtropical Gyre's (SPSG) centre region, followed by the high-latitude continental region under the influence of the onshore West Wind Drift, and decreased along the continental alongshore upwelling current, towards lower latitudes. Apart from pelagic rafters, a wide range of benthic epibionts, including invasive and cryptogenic species, was found on rafts at the continental beaches. Similarly, we present another record of local benthic corals Pocillopora sp., on Rapa Nui rafts.

Discussion

Our results agree with the predictions made by recent models based on the prevailing wind and surface current regimes, with high frequencies of long-distance rafting in the oceanic SPSG centre and very low frequencies along the continental coast. These findings confirm the suitability of such models in predicting arrival hotspots of AMD and rafting species. Moreover, storm surges as well as site-related factors seem to influence AMD arrival patterns along the Chilean continental coast and might cause the observed high variability between sampling sites and days. Our results highlight the possible importance of rafting as a vector of along-shore dispersal and range expansions along the SE Pacific continental coast and add to the discussion about its role in benthic species dispersal between South Pacific oceanic islands.

Analysis and forecasting of national marine litter based on coastal data in South Korea from 2009 to 2021

In this study, statistical analysis and forecasting were performed using coastal litter data of Korea. The analysis indicated that rope and vinyl accounted for the highest proportion of coastal litter items. The statistical analysis of the national coastal litter trends revealed that the greatest concentration of litter was observed during summer months (June-August). To predict the amount of coastal litter per meter, recurrent neural network (RNN)-based models were used. Neural basis expansion analysis for interpretable time series forecasting (N-BEATS) and neural hierarchical interpolation for time series forecasting (N-HiTS), an improved model of N-BEATS recently announced, were used for comparison with RNN-based models. When predictive performance and trend followability were evaluated, overall N-BEATS and N-HiTS outperformed RNN-based models. Furthermore, we found that average of N-BEATS and N-HiTS models yielded better results than using one model.

Investigating variability among fisheries litter accumulation on beaches in Paraná, Brazil

Fishing activities strongly influence coastal and marine environments and are responsible for generating marine litter. In southern Brazil, there are several artisanal (small-scale) fisher settlements that potentially contribute towards regional marine litter. The present study sought to address the deficit in available information by investigating the in situ contribution of artisanal fishing communities to marine litter on adjacent beaches. During one month in the 2019 austral winter, 200-m stretches of beach were investigated at four locations (three artisanal fishing and one control community) in Paraná state. In total, 2196 items were collected; among which only 104 (<5 %) were fisheries related and these remained partially independent of the presence of the three fishing communities across both small and large spatial scales (i.e., from m to km). Rather than the presence of fishing communities, fisheries-related litter appears to primarily originate from external sources and may regionally accumulate via natural vectors such as oceanic currents.

Density variability of COVID-19 face mask litter: A cautionary tale for pandemic PPE waste monitoring

Despite the requirement for data to be normally distributed with variance being independent of the mean, some studies of plastic litter, including COVID-19 face masks, have not tested for these assumptions before embarking on analyses using parametric statistics. Investigation of new data and secondary analyses of published literature data indicate that face masks are not normally distributed and that variances are not independent of mean densities. In consequence, it is necessary to either use nonparametric analyses or to transform data prior to undertaking parametric approaches. For the new data set, spatial and temporal variance functions indicate that according to Taylor's Power Law, the fourth-root transformation will offer most promise for stabilizing variance about the mean.

Sources and management of marine litter pollution along the Bay of Bengal coast of Bangladesh

Marine debris is often detected everywhere in the oceans after it enters the marine ecosystems from various sources. Marine litter pollution is a major threat to the marine ecosystem in Bangladesh. A preliminary study was conducted to identify the sources of marine litter (plastics, foamed plastic, clothes, glass, ceramic, metals, paper, and cardboard) along the Bay of Bengal coast. From the observations, the range of abundance of the collected marine litter was 0.14-0.58 items/m². From the ten sampling sites, the highest amount of marine litter was observed for aluminium cans (3500), followed by plastic bottles (3200). The spatial distribution pattern indicated that all the study areas had beach litter of all types of materials. The present investigation showed that plastics were the dominating pollutants in the marine ecosystem in Bangladesh. The clean-coast index (CCI) value indicated that the Cox's Bazar coast was clean to dirty class. The abundance, distribution, and pollution of marine litter along the coastal belts pose a potential threat to the entire ecosystem. This study will help come up with ways to manage and get rid of marine litter along the coast in an effective way.

The spatiotemporal dynamics, distribution, and characteristics of beached plastics along the remote south coast of Western Australia

Understanding the accumulation mechanism for beached plastics is important for marine debris research. Similar to the global accumulation pattern for beached plastics, we find that along the remote south coast of Western Australia (SCWA) white, hard, microplastics dominate the microplastic pollution accumulating on beaches. We estimate that along the SCWA, plastics are present at a density of 2.01 items·m^-2, but also find that the density of plastic pollution is higher at the eastern end of bays. Significantly fewer plastics were found after easterly winds (austral summer-prevailing winds), and regional physical ocean process, including the Leeuwin Current, and the Ekman transport effect may be relevant to the rate of plastic accumulation on SCWA beaches.

Abundance and composition of marine litter on the coasts of the Dardanelles (Canakkale Strait, Turkey)

The amount of human-origin litter in sea surface water, sediment, and beaches has been increasing for decades. Initially described in marine coastal systems in the 1960s, marine litter (ML) is nowadays commonly observed in all marine systems. There is even a gigantic island consisting of garbage in the gyre area of the Atlantic Ocean. In relation to this significant problem, ML was collected from seven stations on beaches along the Dardanelles for the first time in the period May 2017-May 2018 and was seasonally and regionally analyzed in terms of densities and weights. ML was categorized by material type (plastic, rubber, paper, etc.) and field of use (mixed packaging wastes, personal use products, fishing wastes, etc.). Total numbers and weights of ML during the study were 5751 items and 115.7 kg in an area of 15,980 m², respectively. Density and weight of ML ranged from 0.050 to 1.182 items/m² and from 0.446 to 78.46 g/m², respectively. The main ML component was plastic items in terms of both density (90.95%) and weight (53.76%) according to material type. Additionally, mixed packaging wastes (MPW) were the most common ML items in terms of density (82.14%) and weight (49.38%) according to usage. According to the clean-coast index, while Kilya (St.2) and Kepez (St.5) beaches were dirty, Seddulbahir (St.1) beach was clean. The beaches in other stations were neither dirty nor clean (medium) according to the index. At the end of the study, suggestions for a regional strategy were made.

Global marine litter research 2015-2020: Geographical and methodological trends

A systematic review of research on marine macrolitter densities in the past five years (2015-2020) revealed considerable knowledge gaps in the field. Nearly half he reviewed studies were on stranded litter. Data are scarce from many of the regions estimated to mismanage the largest amounts of plastic waste. In regions where data are available these are typically from coastal areas with few data from the high and deep seas; 57% and 87% of studies on pelagic and seafloor litter, respectively, took place within 100 km from shore. Data on pelagic litter are generally constrained to the sea surface and only two of 30 pelagic studies have measured macrolitter deeper in the water column. Reported litter densities are generally highest for stranded litter, although seafloor litter densities by weight are high in some areas. Reported densities of floating litter are several orders of magnitude lower. However, a lack of standardisation of methods makes it difficult both to assess and to compare litter densities within and across the different environmental compartments in time and space. The review illustrates a great need for survey design development within the field of macroplastics and point to some long-established considerations from ecological research pertaining to independence of data points, spatial autocorrelation, sampling scale, and plot size and shape which are highly relevant also for marine litter research. These considerations are relevant both for global standardisation efforts and for independent studies. Furthermore, the knowledge gaps created by geographic and compartment biases in research needs to be addressed to identify further research needs, validate models and inform policy.

Source, fate and management of recreational fishing marine debris

Marine debris, directly and indirectly, threatens marine habitat and biota. Fishing activity is generally recognised as a contributor to marine debris, but the relative input from recreational fishing remains unassessed. Here we provide the first comprehensive literature review of recreational fishing marine debris (RFMD) on a global scale. A systematic literature review identified 70 studies related to RFMD, and plastic and metal respectively were the dominant debris materials found. Nearshore coastal areas and reefs, acted as both sources and sinks of RFMD and a diverse suite of potential impacts such as ghost fishing and entanglement were identified at local scales. Overall, research of RFMD is lacking globally, however, its role in marine debris input is likely underestimated. We recommend more research on the volumes and risks, using a standardised classification approach. Where intervention is required, we suggest cooperative approaches between the sector and authorities.

Is conscientious beachcombing the key to 'unlock' marine plastic pollution trends through citizen science? A case study from Cockburn Sound, Western Australia

Despite the global implementation of plastic waste reduction policies and bans on single use plastics (SuPs), their effectiveness for protecting marine ecosystems remains unclear. Frequent monitoring could confirm policy effectiveness, but this is difficult due to resourcing and logistic constraints. This study tested a 'beach litter' beachcombing citizen science approach that could overcome some constraints. Between November 2018 and January 2021, 168 beach visits led to the collection of 12,659 pieces of litter from a beach in Western Australia. Litter was predominantly plastic (87%) and mostly associated with fishing/boating (34%). Significant reductions in six types of litter, including fishing/boating items, balloons, and straws were detected and four coincided with local government waste mitigation measures. We show potential to harness conscientious beachcombers as citizen scientists to help evaluate plastic policy impact. Furthermore, we propose how to harness this effort and increase spatial and temporal coverage of marine plastic pollution monitoring.

Deposition rates and residence time of litter varies among beaches in the Lofoten archipelago, Norway

A considerable portion of marine litter pollutes the world's coastlines. Its accumulation on beaches represents the product of deposition and retention, processes which are not well understood. A mark-recapture study was performed with a two-week sampling interval at three sites in Lofoten, Norway. Deposition and retention vary over relatively small spatial scales (approx. 13 km radius). No correlation was found among sites in the timing of high and low deposition events, suggesting these are governed by local factors. Contrastingly, the correlation in the timing of high and low retention events was generally stronger among sites, suggesting these may be affected by regional factors. The results underline the importance of customising cleanup frequency for different beaches as spatiotemporal variation in the relative importance of deposition and retention dictate the optimal frequency for maximal removal of litter from circulation in the local marine environment, which cannot be discerned from accumulation (i.e., standing stock) alone.

Microplastic distribution within core sediments of beach and its responses to anthropogenic activities

Nowadays, people have known more about the distribution features on the surface of beaches. However, the understanding on the microplastics (Mps) distribution in the vertical direction on beaches is still lacking. This study analysed the vertical distribution of Mps from five beaches, with one long core [Shilaoren Beach (C1), 8 m] and four short cores [Aoshan Beach (C2); Liuqinghewan Beach (C3); Bathing Beach No. 3 (C4); and Golden Beach (C5); approximately 70 cm]. An increasing trend of Mps from bottom to top layers were observed with an average of 16.6 ± 4.8 Mps/25 g d.w. in C1. Conversely, a fluctuating trend was found in C2-C5, with an average Mps abundance on the 70 cm depth to be 6.7, 7.1, 11.1 and 7.0 Mps/25 g d.w., respectively. These Mps were mainly comprised of fibres (>98%) and few were fragments. Mps were not uniformly distributed within all cores, and this variation was due to changes in Mps sources, hydrodynamics and sedimentation process in the beach environment. Although the vertical accumulation of Mps is not as stable as the other sedimentary environments, it still presents the increasing trend in the 8-m core from the bottom to the top, which is consistent with the plastic production history in China since 1950. Therefore, the 8-m core has been deposited on the beach in the recent 70 years. Thus, this study provides a valuable example for tracing the sedimentation history on the beach, which can help in understanding the sediment deposit and transport processes with time on beaches.

Macro marine litter survey of sandy beaches along the Cox's Bazar Coast of Bay of Bengal, Bangladesh: Land-based sources of solid litter pollution

Macro-sized marine litter (>2.5 cm) was collected, characterized, and enumerated along the Cox's Bazar Coast, Bangladesh. Marine litter abundance was converted to density (number of items/m²). Beach cleanliness was evaluated using the clean-coast index (CCI). Plastic polythene bags were the most abundant litter items, followed by plastic cups. Total marine litter abundance was 54,401 ± 184 items. Major sources of marine litter were from tourism, fishery and residential activities. Of 10 sites surveyed, two were classified as dirty, two were moderate, four were clean and two were very clean using the CCI. Marine litter pollution along the Cox's Bazar Coast represents a potential threat to coastal and marine environments. This baseline study will help to establish mitigation strategies that are urgently required to reduce marine litter pollution along the Cox's Bazar Coast.

Low quantities of marine debris at the northern Ningaloo Marine Park, Western Australia, influenced by visitation and accessibility

Marine debris (MD) is a serious environmental concern globally. Yet, few studies have reported on MD in sanctuary zones of the Indian Ocean. Consequently, coastal transects were conducted to determine MD quantity, composition and distribution at northern Ningaloo Marine Park, Western Australia. Debris density ranged between 0.004 and 0.02 items m^-2 with the greatest density near Exmouth township. Composition was predominantly plastic (61%) with fishing-related items (25.5%) and plastic fragments/remnants (16%) the most numerous overall. Land-based and general sourced MD accounted for 88% of all debris. Debris levels were significantly lower at sites with higher visitation and increased distance from access points. There was no significant difference between sanctuary and non-sanctuary zones. Although not immune to MD, this study suggests its remote location, environmental awareness and management strategies implemented at Ningaloo Marine Park may be key to its low MD levels.

Getting butts off the beach: Policy alone is not effective at reducing cigarette filter litter on beaches in Maui, Hawai'i

Cigarette filters are made of non-biodegradable plastic and are one of the top littered items worldwide. Here, we determine if policy implementation is an effective strategy for reducing cigarette filter litter on beaches in Maui, Hawai'i by comparing cigarette filter counts before and after a policy banning tobacco use was implemented. We use a before-after control-impact (BACI) design to investigate whether changes in cigarette filter accumulation at an impact site, where tobacco use was banned, decreased relative to counts at a control site, where tobacco use was not banned. A total of 764 cigarette filters were removed with no significant difference detected in cigarette filter littering between the control and impact site after the policy went into place. This study shows that policy requiring a shift from social norms, such as tossing cigarette butts, needs to be accompanied by sustained law enforcement and awareness around the policy to be effective.

Stranded marine debris on the touristic beaches in the south of Bali Island, Indonesia: The spatiotemporal abundance and characteristic

Stranded marine debris (MD) has become a hot topic on Bali Island because it threatens coastal tourism sustainability. This study aims to investigate the spatiotemporal abundance and characteristics of MD on 14 touristic beaches in Bali Island. Sampling is carried out twice every season by adapting methods from NOAA's MD program. We found that the average MD abundance and weight were 0.356 ± 0.366 items/m² and 4.057 ± 3.892 g/m², respectively. Plastic dominated the MD based on abundance (86.9%) and weight (40.1%). Plastic bags, straws, and plastic cups are the most common items among plastics. The MD is originated from Indonesia and is dominated by land-based sources. The beaches are categorized as dirty in the rainy seasons and clean in the dry seasons. Statistically, the MD based on abundance, weight, category, source, and level of cleanliness varied significantly between seasons.

Daily environmental variation influences temporal patterns of marine debris deposition along an estuarine outlet in southern Brazil

The influence of short-term (daily) variation in environmental conditions (rainfall, wind, tide, river flow) on debris accumulation was examined on two beaches at an estuarine outlet. Sampling occurred over 60 consecutive days along two sections (Internal Area, IA; and External Area, EA) of the Paranaguá Estuary Complex's southern outlet, in Paraná, southern Brazil. The IA is sheltered from direct wave action, whereas the EA is more exposed to wave and wind action from the open ocean. The IA accounted for 71% of the total debris, while the EA accounted for 29%. Debris abundance was highest after intermediate bouts of rainfall, although river flow only affected debris accumulation in the IA. Wind and tide influenced accumulation differently across sites. These results highlight the importance of short-term variation in the accumulation of marine debris on sandy beaches, which should be considered when designing and monitoring assessment programs and removal strategies.

Records of marine litter contamination in tropical beaches (Sergipe, Brazil) with different uses

This study aimed to develop a first diagnostic of marine litter presence over four sandy beaches located on the southern coast of Sergipe, a Brazilian state, by means of four samplings, from December 2017 to September 2018. There was no distinction between village, semi-rural, and rural areas regarding litter presence. Plastic was the most abundant litter (> 70%), mainly represented by the items such as food packaging, cups, straws, cigarette butts, lids/seals, as well as fragments and monofilaments. The abundance of items collected ranged from 0.1 and 9.2 items.m^-1, and the beaches were characterized from very clean to dirty. The main sources were from tourism/recreation (42.7 ± 4.8%), followed by Unidentified (34.1 ± 6.7%), and Fishing/Marine activities (16.1 ± 6.3%). In addition, we highlight the importance of the correct litter management, environmental education activities, and marine litter monitoring program in order to reduce marine litter contamination.

Daily accumulation rates of marine litter on the shores of Rapa Nui (Easter Island) in the South Pacific Ocean

Large amounts of floating litter accumulate in the subtropical gyres, and the shorelines of oceanic islands in the vicinity of these accumulation zones receive large amounts of litter. The dynamics of marine litter arrival were evaluated on a small pocket beach on Rapa Nui (Easter Island) between November 2016 and June 2017 over a total time period of 190 days. Plastics dominated the stranded litter, with the majority of the items showing indications to come from the high seas fisheries operating in the South Pacific. Litter accumulation rates varied between 0 and 1.90 items m^-1 day^-1, and were highest following days of strong winds from northern directions. The results indicate that the shores of Rapa Nui are exposed to continuous input of plastic litter from the contaminated waters of the subtropical gyre, which is intensified during strong onshore winds.

Temporal patterns in the abundance, type and composition of microplastics on the coast of the Río de la Plata estuary

The objective was to establish possible temporal patterns in the microplastics (MPs) abundance in the water and in the intertidal sediment in an urbanized location of the Río de la Plata estuary (Argentina), in relation to environmental factors. The site was sampled monthly for a year (February 2019-January 2020). The presence of MPs was recorded, being more abundant in February in the water (110 MPs m^-3) and in April in the sediment (613 MPs m^-2). The types of MPs found were fibers, fragments, pellets, film and foam; while the polymers identified were polyethylene (PE) and polypropylene (PP). Regarding the environmental variables, the predominance of wind from the NE direction was related to a greater accumulation of MPs in the sediment, while wind from the NO direction was associated with a lower abundance of MPs in the water. Also, MPs abundance was negatively related to the larger sizes of sediment particles.

Temporal trends of marine litter in a tropical recreational beach: A case study of Mkomani beach, Kenya

Six marine litter standing stock surveys were carried out to determine the influence of monsoon on the temporal abundance and composition of macro-litter in Mkomani beach, Mombasa Kenya. Foam (0.073 items m^-2) and plastic (0.042 items m^-2) fragments had the highest densities. The brand audit indicated that 66.9% of branded marine litter was of Kenyan origin. Food product packaging contributed 78.4% of the branded litter with PET bottles being the most abundant type of packaging (48.2%). Foreign products contributed 35.6% of branded marine litter during South East Monsoon (SEM) whereas only 11.7% during North-East Monsoon (NEM). Worth noting, PET packaging dominated during SEM (53.6%) compared to NEM (20.2%). Mkomani beach could be considered "extremely dirty" with a Clean-Coast Index greater than 20. The study concludes that monsoons influences litter diversity, richness and evenness.

Mangroves as unique but understudied traps for anthropogenic marine debris: A review of present information and the way forward

Marine debris and plastic pollution affect all coastal habitats, however coastal debris studies are predominantly performed on sandy beaches. Other coastal habitats, such as mangroves, remain understudied. Eighteen of the top twenty rivers that contribute the most plastic to the ocean are associated with mangroves, but very few of those forests were investigated in terms of plastic debris pollution. Here we discuss the results of the few available studies on macrodebris conducted in mangroves, which show that mangrove debris research is still in its early stages, with many areas of study to be further investigated. Indeed, the distinct structural complexity of mangroves increases their ability to trap debris from both terrestrial, freshwater and marine sources, resulting in impacts unique to the mangrove ecosystem. Our review highlights a significant lack in standardisation across the performed surveys. Here we suggest standardised guidelines for future integrated macrodebris and microplastic studies in mangroves to facilitate comparisons between studies. Such standardisation should prioritize the use of stratified random sampling, the measurement of the area covered by the debris and the abundance and type of macrodebris and microplastics found, in order to assess the ecological impact of macrodebris and its role as source of microplastics for adjacent ecosystems. We also advocate the use of standard categories across studies, based on those identified for surveying other coastal habitats. This review highlights an alarming knowledge gap in extent, sources and overall impacts of marine macrodebris, mainly constituted by plastic, on mangrove forests, which hinders policy making to address this issue. Standardised, reliable and extended research on this aspect of mangrove pollution is needed to manage and protect these endangered vegetated coastal ecosystems.

Beach-dune morphodynamics and marine macro-litter abundance: An integrated approach with Unmanned Aerial System

This work shows an integrated approach for coastal environmental monitoring, which aimed to understand the relation between beach-dune morphodynamics, marine litter abundance and environmental forcing. Three unmanned aerial system (UAS) flights were deployed on a beach-dune system at the Atlantic Portuguese coast to assess two main goals: (i) quantifying the morphological changes that occurred among flights, with focus on dune erosion, and (ii) mapping the changes of marine macro-litter abundance on the shore. Two most vulnerable-to-erosion sectors of the beach were identified. In the northern sector, the groin affected the downdrift shoreline, with dune erosion of about 1 m. In the central part of the beach, the dunes recessed about 4 m during the winter, being more exposed to environmental forcing due to the absence of dune vegetation. Marine litter occupation area on the beach decreased from 25% to 20% over the winter, with octopus pots (13%) and fragments (69%) being the most abundant items on average. Litter distribution varied in relation to swash elevation, wind speed and direction. With low swash elevation, the wind played a predominant role in moving the stranded items northwards, whereas high swash elevation concentrated the items at the dune foot. This study emphasizes the potential of UAS in allowing an integrated approach for coastal erosion monitoring and marine litter mapping, and set the ground for marine litter dynamic modelling on the shore.

The generation of marine litter in Mediterranean island beaches as an effect of tourism and its mitigation

The Mediterranean Sea and its coastal systems are threatened by intense anthropogenic pressures including rapid accumulation of marine litter by diverse human activities. The region, which is the world's leading touristic destination, has to face a seasonal increase of waste generation due to the seasonal influx of visitors. The beaches, extremely crowded during the summer, are particularly vulnerable since they are proven to be concentrated accumulation zones and one of the main gateways of litter to enter the marine system. We found that the accumulation rates of marine litter on Mediterranean island beaches follow a seasonal pattern, increasing up to 4.7 times during the high season, representing a daily load of (40.6 ± 11.5) 10⁶ items/day extrapolated to all the islands of the region. We developed an accumulation index to assess the dynamics of marine litter and support efficient mitigation strategies by local authorities. To limit marine litter production attributable to recreational activities, a series of pilot actions implemented during the high touristic season, demonstrated a substantial reduction (up to 52.5%). The implementation towards an efficient and sustainable tourism business model is urgently required.

A snapshot of the litter problem along the Viña del Mar - Concón coastal strip, Valparaíso region, Chile

Along the Viña del Mar - Concón coastal strip 11,894 litter items were collected, and grouped into 48 different categories (11 litter typologies). The average litter abundance was 0.25 items/m², plastic items, and cigarette butts being the most common. Hazardous litter can be found along the entire study area, reaching 28.9% (3438 items of 11,894 total items collected distributed in 14 different categories), and an average of 0.071 items/m². The application of environmental evaluation indices based on litter data, allows categorizing the study area as a clean-moderate coastal strip with some presence of hazardous litter items, and unsatisfactory environmental conditions. Studied sectors were statistically grouped into three specific types that ranged from sectors in optimal environmental conditions (Group A) to sectors in adverse environmental conditions (Group C). The typology and magnitudes of litter found along the study area suggest a combination of sources that mainly include direct activities on the beach (recreational and smoking-related) as well dumping. In the same way, sanitary waste, ocean/waterway items, and items related to surfing activities were observed. Strategies for litter management and environmental quality improvement need to be developed and enforced.

Marine debris in Moroccan Mediterranean beaches: An assessment of their abundance, composition and sources

Morocco is well known for its attractive Mediterranean beaches, which play an important economic role. With the fast development and growth, these beaches have become more contaminated by marine debris. This paper examined the abundance, composition and marine debris sources on five beaches in the Moroccan Mediterranean during 2019 four seasons. A total of 7839 marine debris were collected from the five beaches with a total weight of 231 kg. The average density of the debris collected was 0.20 ± 0.098 items/m². Polymer materials constituted the majority of debris found, with a percentage of 71.36%, followed by paper/cardboard (11.50%), metal (5.77%), processed wood (5.34%), cloth/textile (2.51%) and glass/ceramics (1.76%). Human recreational activities were the main source of debris (70.13%), followed by smoking-related (13.98%). Debris density appears to be particularly influenced by beach users. Awareness campaigns are needed for beach users to improve the quality of the beaches.

Reporting Guidelines to Increase the Reproducibility and Comparability of Research on Microplastics

The ubiquitous pollution of the environment with microplastics, a diverse suite of contaminants, is of growing concern for science and currently receives considerable public, political, and academic attention. The potential impact of microplastics in the environment has prompted a great deal of research in recent years. Many diverse methods have been developed to answer different questions about microplastic pollution, from sources, transport, and fate in the environment, and about effects on humans and wildlife. These methods are often insufficiently described, making studies neither comparable nor reproducible. The proliferation of new microplastic investigations and cross-study syntheses to answer larger scale questions are hampered. This diverse group of 23 researchers think these issues can begin to be overcome through the adoption of a set of reporting guidelines. This collaboration was created using an open science framework that we detail for future use. Here, we suggest harmonized reporting guidelines for microplastic studies in environmental and laboratory settings through all steps of a typical study, including best practices for reporting materials, quality assurance/quality control, data, field sampling, sample preparation, microplastic identification, microplastic categorization, microplastic quantification, and considerations for toxicology studies. We developed three easy to use documents, a detailed document, a checklist, and a mind map, that can be used to reference the reporting guidelines quickly. We intend that these reporting guidelines support the annotation, dissemination, interpretation, reviewing, and synthesis of microplastic research. Through open access licensing (CC BY 4.0), these documents aim to increase the validity, reproducibility, and comparability of studies in this field for the benefit of the global community.

Composition, abundance and sources of anthropogenic marine debris on the beaches from Ecuador - A volunteer-supported study

This study represents an inter-institutional effort that was supported by more than 400 volunteers. We sampled Anthropogenic Marine Debris (AMD) on 26 beaches, including one beach from Galapagos Islands. AMD was mainly composed of plastics (>60%), followed by cigarette butts, paper and metal. Average AMD density on the continental beaches was 1.31 ± 1.03 items m^-2 (mean ± SD). AMD densities and the proportion of plastics were higher on some beaches located on the Gulf of Guayaquil, suggesting that many of the plastic items found on these beaches were, likely, drifted by the swift currents of the Guayas River. Additionally, the overall results indicate that most litter on continental beaches from Ecuador has local sources. Recommendations include marine pollution education and public awareness campaigns to reduce the consumption of plastic bags, as well as a ban on harmful single-use plastics.

Citizen science data indicate a reduction in beach litter in the Lofoten archipelago in the Norwegian Sea

Marine litter is a major global challenge, even in the remote reaches of the Arctic. Monitoring temporal trends in litter loadings and composition is key to designing effective preventative and mitigative measures, and to assess their impact. Few data are available, however, by which to do this in the Arctic region. Citizen science data organised by the local waste management company in the Lofoten archipelago in the Norwegian Sea is an exception to this. We analysed volunteer cleanup data (total weight and counts of select litter types, standardised to density per 100 m) from over 200 locations from 2011 to 2018. Results indicate a general decline in beach litter in the region, and particularly in litter types related to private use, such as beverage bottles. These declines are most likely the combined result of extensive cleanup activities and a considerable reduction in local litter inputs.

Plastic pollution in paradise: Daily accumulation rates of marine litter on Cousine Island, Seychelles

The daily accumulation rates, composition, sizes and potential sources of marine litter collected on a remote island within the Western Indian Ocean were investigated. In total, 9119 items of marine litter were collected during 40 surveys, which equated to 0.0082 items·m^-1·d^-1. Between 2003 and 2019 there was a significant increase in the amount of litter deposited, with the highest daily accumulation rate recorded in 2019 (0.0255 items·m^-1·year^-1). All specific litter types increased over time and also differed significantly in their accumulation rates, with polystyrene fragments/pieces (0.00249 items·m^-1·d^-1), plastic items (0.00135 items·m^-1·d^-1) and plastic bottles (0.0011 items·m^-1·d^-1) being the most commonly encountered during this study. The majority of the litter found was ≤5 cm in size. Nearly all (>80%) litter collected was made of or contained some form of plastic. Recommendations for improved management of litter and the importance of establishing regular beach clean-ups within the Seychelles are briefly discussed.

Marine debris: A review of impacts and global initiatives

Marine debris, defined as any persistent manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment, has been highlighted as a contaminant of global environmental and economic concern. The five main categories of marine debris comprise of plastic, paper, metal, textile, glass and rubber. Plastics is recognised as the major constituent of marine debris, representing between 50% and 90% of the total marine debris found globally. Between 4.8 and 12.7 million metric tonnes of consumer plastics end up in the world oceans annually, resulting in the presence of more than 100 million particles of macroplastics in only 12 regional seas worldwide, and with 51 trillion particles of microplastic floating on the ocean surface globally. The impacts of marine debris can be branched out into three categories; injury to or death of marine organisms, harm to marine environment and effects on human health and economy. Marine mammals often accidentally ingest marine debris because of its appearance that can easily be mistaken as food. Moreover, floating plastics may act as vehicles for chemicals and/or environmental contaminants, which may be absorbed on to their surface during their use and permanence into the environment. Additionally, floating plastics is a potential vector for the introduction of invasive species that get attached to it, into the marine environment. In addition, human beings are not excluded from the impact of marine debris as they become exposed to microplastics through seafood consumption. Moreover, landscape degradation owing to debris accumulation is an eyesore and aesthetically unpleasant, thus resulting in decreased tourism and subsequent income loss. There are a wide range of initiatives that have been taken to tackle the issue of marine debris. They may involve manual removal of marine debris from coastal and aquatic environment in form of programmes and projects organised, such as beach clean-ups by scientific communities, non-governmental organizations and the removal of marine litter from Europe's four regional seas, respectively. Other initiatives focus on assessment, reduction, prevention and management of marine debris under the umbrella of international (the United Nations Environment Programme/Mediterranean Action Plan, the Oslo/Paris Convention) and regional organisations - that is, the Helsinki Commission. There are also a number of international conventions and national regulations that encourage mitigation and management of marine debris. However, it is argued that these initiatives are short-term unsustainable solutions and the long-term sustainable solution would be adoption of circular economy. Similarly, four of the sustainable developmental goals have targets that promote mitigation of marine debris by efficient waste management and practice of 3R. As evident by the Ad Hoc Expert Group on Marine Litter and Microplastics meeting, tackling the marine debris crisis is not a straightforward, one-size-fits-all solution, but rather an integrated and continuous effort required at local, regional and global level.

Wind, waves, tides, and human error? - Influences on litter abundance and composition on German North Sea coastlines: An exploratory analysis

Being globally and locally prevalent, beach litter has been monitored at 29 sites along the German North Sea coastline. This study offers an exploratory analysis of data from 1991 to 2016. Schleswig-Holstein exhibited lower mean litter pollution levels than Lower Saxony, possibly because the locations in Lower Saxony are situated along the main coastal current, whereas the North Frisian Islands act as a barrier for the mainland sites in Schleswig-Holstein. Locations close to the Elbe estuary had significantly larger amounts of debris, likely receiving litter from marine and riverine sources. No clear overall pattern in litter abundance or composition could be detected. Significant quantitative similarities between debris types were inconsistent. The effect of wind, tides, and exposure appeared to be marginal. Recurring data inconsistencies, gaps, and outliers were partly attributed to human error. This could be reduced through hypothesis-driven monitoring with a simpler litter classification and continuous data checking.

Application of Matrix Scoring Techniques to evaluate marine debris sources in the remote islands of the Azores Archipelago

Three-quarters of all marine debris (MD) consists of plastic, a reflection of their worldwide use, production and waste mismanagement. Data on MD distributions can improve our ability to effectively reduce debris that escapes onto shorelines and the ocean. In this study, the Matrix Scoring Technique (Marine Strategy Framework Directive Technical Group on Marine Litter) was applied as an approach to calculate the likelihood of single debris items originating from a series of potential sources. Factors considered were: identity and function of debris, beach location, influential activities, "mix" of debris found, presence of indicator items, and quantity of MD. The standing-stock (abundance and composition) of MD was investigated in two sandy beaches (Conceição and Porto Pim) of the Azores Archipelago (NE Atlantic) for the period 2012-2018. The results of this study show promise towards the implementation of a new classification method to determine beach debris sources in remote open-ocean areas.

Spatial trends and drivers of marine debris accumulation on shorelines in South Eleuthera, The Bahamas using citizen science

This study measured spatial distribution of marine debris stranded on beaches in South Eleuthera, The Bahamas. Citizen science, fetch modeling, relative exposure index and predictive mapping were used to determine marine debris source and abundance. Citizen scientists quantified debris type and abundance on 16 beaches within three coastal exposures (The Atlantic Ocean, Great Bahama Bank and The Exuma Sound) in South Eleuthera. Marine debris, (~2.5 cm or larger) on each beach was monitored twice between March-May and September-November 2013 at the same locations using GPS. Approximately, 93% of all debris items were plastic with plastic fragments (≤2.5 cm) being the most common. There were spatial differences (p ≤ 0.0001) in plastic debris abundance between coastal exposures. Atlantic Ocean beaches had larger quantities of plastic debris by weight and by meter (m) of shoreline. Stranded plastic may be associated with Atlantic Ocean currents associated with leakage from the North Atlantic sub-tropical gyre.

Fishing marine debris in a northeast Brazilian beach: Composition, abundance and tidal changes

This study aims to examine the composition and the spatial/tidal changes of marine debris caught with a fishing net during a fishery survey in two different areas of a sand beach at the northeast of Brazil. Samples were conducted weekly, at each moon phase, for two months using a beach seine net in the surf zone. Abundance of debris were estimate by swept area (items·km^-1 and g·km^-1). A total of 12 categories of debris were recorded. Plastic - both hard and soft types - was the most abundant debris category. Most fragments were classified as macro (20-100 mm) and mega debris (>100 mm). Significant differences (P < 0.05) between areas and tides were registered for plastic, metal and cloth. Spring tides were responsible for the high rates of marine debris found in the surf zone of Miramar beach. The results demonstrate the occurrence and abundance of litter in this fish nursery area and reinforce the need and importance of environmental protection and educational programs. CAPSULE ABSTRACT: Marine debris caught by a fishing net in the surf zone of Brazilian beach.

Spatio-temporal monitoring of coastal floating marine debris in the Balearic Islands from sea-cleaning boats

Mismanaged waste is accumulating at an alarming rate in the marine environment. Its presence has caused local authorities in the Balearic Islands to develop a coastal sea-cleaning boat service covering the region, identifying the floating marine debris, and removing it from the coastal areas. This study considered daily monitoring from May to October spanning from 2005 to 2015. Plastic marine debris composed over 54% of all floating marine debris removed daily across the Balearic Islands. The spatio-temporal patterns indicate a heterogeneous distribution of plastic in the coastal areas, with higher concentrations in the north-western and south-eastern regions of the islands and debris peaking during the month of August. Furthermore, floating marine debris was more easily collected during calm seas as well as using an integrated monitoring approach to facilitate its removal. Overall, sea-cleaning boats are highly effective in removing coastal floating marine debris.

Marine debris at nesting grounds used by the Northern Gulf of Mexico loggerhead recovery unit

Anthropogenic marine debris (AMD) can cause obstructions for nesting marine turtles and hatchlings, increase their exposure to toxicants, and potentially alter the incubating environment of clutches. Given the potential impacts of AMD on marine turtles, this study provides baseline information on the abundance and distribution of AMD at the ten highest density nesting beaches in Florida used by the Northern Gulf of Mexico Loggerhead Recovery Unit. Monitoring for AMD at nesting beaches was conducted in 2017 following protocols from the International Coastal Cleanup. AMD was present at all the nesting beaches, with the majority of AMD observed at the westernmost sites beginning with St. Joseph Peninsula State Park (363 AMD/km) with a gradual decrease of abundance to the easternmost site, Alligator Point (16 AMD/km). Plastic and foam items accounted for 92% (n = 13,566) of all AMD found.

Influence of oceanographic and meteorological events on the quantity and quality of marine debris along an estuarine gradient

The influence of three meteorological/oceanographic conditions - frontal systems (FS), high riverine discharges (HRD) and regular weather conditions (RWC) - over the quantity (Overall Abundance and Richness of types) and quality (composition and most probable source) of marine debris was assessed in sand beaches along three sectors (internal, I; median, M; and external, E) of an estuarine gradient. The highest overall abundance and richness of types were observed in HRD (I and E), while the lowest were observed in RWC (I and M). The external sector showed lowest abundance in FS. Greatest numbers of "domestic" and "sewage related debris" were observed under HRD (I > E > M). Greatest numbers of "fisheries" items were observed in HRD (I and E). For "unknown" sourced items, there was no indication of a single condition with smaller quantities (E > I = M). Results suggest that adopting oceanographical and meteorological conditions for analysis have the potential to detect temporal variations.

Citizen science for better management: Lessons learned from three Norwegian beach litter data sets

Increased plastic consumption and poor waste management have resulted in litter representing an ever-increasing threat to the marine environment. To identify sources and evaluate mitigation measures, beach litter has been monitored. Using data from two citizen science protocols (CSPs) and OSPAR monitoring of Norwegian beaches, this study 1) identifies the most abundant litter types, 2) compares OSPAR to citizen science data, and 3) examines how to improve the management relevance of beach litter data. The dominant litter types were; food and drink- and fishery related items, and unidentifiable plastic pieces. Data from CSPs are consistent with OSPAR data in abundance and diversity, although few OSPAR beaches limit verification of CSP data. In contrast to OSPAR, the CSPs estimate the weight of the litter. CSPs lack important variables which could explain why some litter types are abundant in some particular areas. The latter could be improved by recording GPS positions.

Connecting flux, deposition and resuspension in coastal debris surveys

For decades, community groups and scientists have sampled coastal waste along shorelines to understand the distribution of debris. However, when debris is washed ashore or locally deposited, it may be washed away before it is removed or recorded. Using statistical models to understand the movement of debris in coastal processes may identify potential sinks of anthropogenic debris. We modelled arrival and departure of debris using data from repeated removal and marking experiments. Both the arrival and departure of debris were affected by the substrate of the shoreline and by seasonal changes (e.g. autumn and winter). Different substrates accumulated different types of debris. The backshore, coastal shape and wind exposure had all affected the departure but not the arrival of debris. Our findings suggest that areas with high accumulation have lower departure, rather than higher arrival of debris. The implication is that counting debris in dirty locations, as when cleanup activities are used for monitoring, will provide a misleading measure of the actual debris in adjoining waters. We found that onshore winds and lower profile backshore vegetation increase the departure of debris. Debris may be moving inland and accumulating in the backshore vegetation, suggesting the backshore vegetation could be a substantial sink of missing marine debris. Overall, inferring the state of plastic pollution in the ocean using one "snapshot" on shore may underestimate the output of debris from land-based sources, whilst overestimating ocean loads near sites that retain or accumulate high levels of debris.

A simple model of wind-blown tidal strandlines: How marine litter is deposited on a mid-latitude, macro-tidal shelf sea beach

A simple hypothesis-driven model of how floating marine plastic litter is blown onto a beach, and then moved on and off the beach by winds and rising and falling water levels is implemented in a computer simulation. The simulation applied to Aberdeen beach, Scotland, suggests that the interaction between varying winds and water levels alone, coupled to an assumed constant offshore floating litter density, can account for 1) the order of magnitude of the long term average (2000-2010) beach plastic litter loading (observed = 127 np/100 m, simulated = 114 np/100 m); 2) the observed frequency spectrum of low water beach plastic litter loadings; 3) the magnitude of the ratio between offshore floating plastic litter densities and onshore beach plastic litter loadings; 4) zero overall net beach plastic litter accumulation. Results are relevant to beach survey design, designing methods to estimate litter accumulation rates and the setting of MSFD beach litter targets.

Spatial distribution of marine litter along italian coastal areas in the Pelagos sanctuary (Ligurian Sea - NW Mediterranean Sea): A focus on natural and urban beaches

Our paper will show data on quantity, typology, distribution of beach litter (Anthropogenic Marine Debris - AMD) within a coastal macroarea surrounding the Pelagos Sanctuary, an International Protected Area in the NW Mediterranean Sea. AMD Monitoring and characterisation have been performed by using SEACleaner Protocol: an adapted version of UNEP/IOC, OSPAR and EU guidelines. 11 beaches located in 5 different areas, have been monitored with a total amount of thirty three surveys, from January 2014 to December 2015, during different seasons. Three kinds of beaches have been considered: Natural (belonging to MPAs), Urbanized and Urban. A total of 34,027 items on a total area of 32,154 m² have been removed and classified. Spatial difference in abundance and composition of AMDs - as well as beach environmental quality - has been detected. Natural sites, and particularly protected areas close to river mouths show a major density compared to other areas.

Rocky shoreline protocols miss microplastics in marine debris surveys (Fogo Island, Newfoundland and Labrador)

Most anthropogenic marine debris shoreline studies are conducted on sandy shores, rather than rocky coastlines. We amended a standardized protocol for monitoring marine debris on a high-loading beach composed of small rocks and cobbles in Newfoundland, Canada. Our protocol had two parts: we conducted stratified sampling to a depth of ~20cm below the surface of the rocks (standing survey), and surveyed accumulation of items on the surface of rocks every other day (loading survey). We found the vast majority of smaller items were below the surface. Only 17.2% of debris were microplastics (<5mm). Types of anthropogenic debris differed significantly between the standing survey and the loading survey. We found no relationship between either wind direction or wind speed, and distributions of debris. This study allows for a better understanding of marine debris detection along rocky coasts, and the limitations of protocols for studying them.

Collected marine litter - A growing waste challenge

Marine litter, in particular plastic debris, poses a serious threat to marine life, human health and the economy. In order to reduce its impact, marine litter collections such as beach clean-ups are frequently conducted. This paper presents a systematic review of temporal developments, geographical distribution, quantities and waste treatment pathways of collected marine litter. Results from over 130 studies and projects highlight the worldwide increase in collection efforts. Many of these are in wealthy countries that do not primarily contribute to the problem. Over 250 thousand tonnes, have already been removed, but there is little or no information available regarding how this waste is treated or used post collection. This paper highlights the need for a whole-system quantitative assessment for the collection and waste treatment of marine litter, and identifies the challenges associated with utilising this waste in the future.

Differential impact of marine debris ingestion during ontogenetic dietary shift of green turtles in Uruguayan waters

Anthropogenic debris ingestion has been reported for green turtles in all their life stages worldwide. The aim of the present study is to evaluate the marine debris ingestion by green turtles stranded in Uruguayan coast between 2005 and 2013. Debris items were categorized and quantified by frequency of occurrence, relative weight, volume and number of items. A total of 96 dead stranded turtles were analyzed and 70% presented debris in their guts. The majority of debris found were plastic, being hard plastics the most abundant in weight. We found no differences in debris ingestion in stranded turtles a long the Uruguayan coast. However we detected a negative correlation between the presence of debris and turtle's size. Smaller turtles are new recruits to neritic grounds indicating that the early juvenile stage of this species is the most vulnerable to this threat in the Southwestern Atlantic.

Tracing the source of marine debris on the beaches of northern New South Wales, Australia: The Bottles on Beaches program

Identifying the source of marine plastic pollution accumulating on ocean beaches is often difficult as unidentifiable fragments of plastic usually predominate. In this study, we surveyed plastic bottles as a relatively identifiable subset of plastics on 30km of beach along a 200-km section of the north coast of New South Wales, Australia. Source and product type (contents) were determined using barcodes, inscriptions/embossing, or bottle shape and characteristics. Country of origin and product type could be determined for two-thirds of the 694 bottles found. Just over half (51%) of these were of domestic origin with the remainder dominated by bottles from China (24%) and south-east Asian countries (21%). As most of the foreign bottles lacked marine growth, and are unavailable for purchase in the region, passing ships are hypothesised as the primary source.

Spatio-temporal variation of anthropogenic marine debris on Chilean beaches

We examined the hypothesis that in an emerging economy such as Chile the abundances of Anthropogenic Marine Debris (AMD) on beaches are increasing over time. The citizen science program Científicos de la Basura ("Litter Scientists") conducted three national surveys (2008, 2012 and 2016) to determine AMD composition, abundance, spatial patterns and temporal trends. AMD was found on all beaches along the entire Chilean coast. Highest percentages of AMD in all surveys were plastics and cigarette butts, which can be attributed to local sources (i.e. beach users). The Antofagasta region in northern Chile had the highest abundance of AMD compared with all other zones. Higher abundances of AMD were found at the upper stations from almost all zones. No significant tendency of increasing or decreasing AMD densities was observed during the 8years covered by our study, which suggests that economic development alone cannot explain temporal trends in AMD densities.

Geophysical features influence the accumulation of beach debris on Caribbean islands

Anthropogenic beach debris was recorded during beach surveys of 24 Caribbean islands during April 2014-April 2016. Beach debris was classified according to material type (e.g., polystyrene) and item use (e.g., fishing). Geophysical features (substrate type, beach direction, and human accessibility) of sample sites were recorded in order to investigate their relationship with debris density. Results suggest the density of macro debris (items >5mm) is highest on uninhabited, sandy beaches facing a leeward direction. Higher debris quantities on inaccessible beaches may be due to less frequent beach clean ups. Frequently accessed beaches exhibited lower macro, but higher micro debris (items 1-5mm) densities, possibly due to removal of macro debris during frequent beach clean ups. This suggests that while geophysical features have some influence on anthropogenic debris densities, high debris densities are occurring on all islands within the Caribbean region regardless of substrate, beach direction, or human accessibility.