The standard techniques for monitoring beach litter focus on the litter that is accumulated on beaches. Therefore, the underwater bathing area is usually overlooked. Our study aims to start the ...discussion about the litter in the bathing area, an important connection between the exposed beach and the ocean. We aimed to compare sampling methodologies between the underwater bathing area and the exposed beach. We highlighted litter's similarities and differences regarding the amount, material, possible sources, and interaction with the biota. We also performed a brand audit on the underwater bathing area litter. In the underwater region, 106 items were collected while 1706 items were collected from the exposed beach region. Plastic was the dominant type of material in both sites, exposed beach (89.92 %) and bathing area (83.96 %). The litter's possible source was different. In the underwater bathing area was more related to food packages (couscous, rice). On the other hand, litter on the exposed beach was associated with beach use (single-use plastic such as plastic cups). The brand audit identified 21 companies, whereby most brands were Brazilian and food-related. Regarding interactions with the biota, the litter in the bathing area had more bio-fouling (87.73 %) than the litter collected on the exposed beach (10.00 %). Information about bathing area litter can be useful to draw different management strategies. Due to the differences in litter types and behavior between the two sites, the same mitigation strategies might not be equally efficient.
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•Methods and beach regions were compared to enhance litter assessment completeness.•Exposed beaches and bathing areas contain different proportions of litter sources.•Brand audit showed local/national companies as major contributors to beach litter.•Biofouling more visible in underwater area than in the exposed beach litter.
•Surgical masks were submitted to artificial aging experiment and seawater exposition.•Microfibers release might result up to 173,000 a day.•Masks collected from marine environment showed similar ...signs of degradation.•Action should be taken to avoid that masks end up in the marine environment.
Due to the Covid-19 pandemic, the use of disposable face masks has been adopted worldwide as a precautionary measure to slow down the transmission of the virus. This has determined an unprecedented rise in the production of these protective equipments, and unfortunately to a new form of environmental contamination due to the improper disposal. To provide a preliminary estimation of the release of microfibers by a surgical mask dumped in the marine environment, we carried out artificial weathering experiments. Results indicated that a single surgical mask submitted to 180 hours UV-light irradiation and vigorous stirring in artificial seawater may release up to 173,000 fibers/ day. Moreover, SEM and micro-FTIR analysis carried out onto surgical masks collected from Italian beaches highlighted the same morphological and chemical degradation signature observed in the masks subjected to the artificially weathering experiments, confirming the risks of a similar microfiber release into the marine environment.
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Microplastics are abundant and widespread in the marine environment. They are a contaminant of global environmental and economic concern. Due to their small size a wide range of marine species, ...including zooplankton can ingest them. Research has shown that microplastics are readily ingested by several zooplankton taxa, with associated negative impacts on biological processes. Zooplankton is a crucial food source for many secondary consumers, consequently this represents a route whereby microplastic could enter the food web and transfer up the trophic levels. In this review we aim to: 1) evaluate the current knowledge base regarding microplastic ingestion by zooplankton in both the laboratory and the field; and 2) summarise the factors which contribute to the bioavailability of microplastics to zooplankton. Current literature shows that microplastic ingestion has been recorded in 39 zooplankton species from 28 taxonomic orders including holo- and meroplanktonic species. The majority of studies occurred under laboratory conditions and negative effects were reported in ten studies (45%) demonstrating effects on feeding behaviour, growth, development, reproduction and lifespan. In contrast, three studies (14%) reported no negative effects from microplastic ingestion. Several physical and biological factors can influence the bioavailability of microplastics to zooplankton, such as size, shape, age and abundance. We identified that microplastics used in experiments are often different to those quantified in the marine environment, particularly in terms of concentration, shape, type and age. We therefore suggest that future research should include microplastics that are more representative of those found in the marine environment at relevant concentrations. Additionally, investigating the effects of microplastic ingestion on a broader range of zooplankton species and life stages, will help to answer key knowledge gaps regarding the effect of microplastic on recruitment, species populations and ultimately broader economic consequences such as impacts on shell- and finfish stocks.
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•We review the effects of microplastic ingestion on zooplankton•Several factors affect microplastic bioavailability to zooplankton•Microplastics in experiments should better represent those found in the environment•Further investigation of different life stages and zooplankton species is needed
Review of the current knowledge regarding microplastic ingestion by zooplankton and summary of factors which contribute to the bioavailability of microplastics to zooplankton.
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•Human are environmentally exposed to microplastics.•Routes of exposure include ingestion, inhalation and dermal contact.•Toxicity may result from particle toxicity, oxidative stress ...and inflammation.•Inflammation may lead to neoplasia and increased translocation of particles.•Microplastic may be involved in the disruption of immune function and neurotoxicity.
Microplastics are ubiquitous environmental contaminants leading to inevitable human exposure. Even so, little is known about the effects of microplastics in human health. Thus, in this work we review the evidence for potential negative effects of microplastics in the human body, focusing on pathways of exposure and toxicity. Exposure may occur by ingestion, inhalation and dermal contact due to the presence of microplastics in products, foodstuff and air. In all biological systems, microplastic exposure may cause particle toxicity, with oxidative stress, inflammatory lesions and increased uptake or translocation. The inability of the immune system to remove synthetic particles may lead to chronic inflammation and increase risk of neoplasia. Furthermore, microplastics may release their constituents, adsorbed contaminants and pathogenic organisms. Nonetheless, knowledge on microplastic toxicity is still limited and largely influenced by exposure concentration, particle properties, adsorbed contaminants, tissues involved and individual susceptibility, requiring further research.
To verify weather mangroves act as sinks for marine litter, we surveyed through visual census 20 forests along the Red Sea and the Arabian Gulf, both in inhabited and remote locations. Anthropogenic ...debris items were counted and classified along transects, and the influence of main drivers of distribution were considered (i.e. land-based and ocean-based sources, density of the forest and properties of the object). We confirmed that distance to major maritime traffic routes significantly affects the density of anthropogenic debris in Red Sea mangrove forests, while this was independent of land-based activities. This suggests ocean-based activities combined with surface currents as major drivers of litter in this basin. Additionally, litter was more abundant where the mangrove density was higher, and object distribution through the mangrove stand often depended on their shape and dimension. We particularly show that pneumatophores act as a sieve retaining large plastic objects, leading to higher plastic mass estimates in mangroves compared to those of beaches previously surveyed in the Red Sea.
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•Surveys aimed at quantifying anthropogenic debris in mangroves stands are scarce.•Mangroves are sinks for marine litter and traps for land originated litter.•Mangroves aerial roots act as a sieve that retains large objects.•Large plastic objects are more frequent in mangroves than on beaches.
Mangrove forests, through pneumatophores, are filters that retain large floating plastic objects and therefore constitute a sink of marine plastic pollution.
Sea turtles are frequently proposed as indicator species for assessing ocean health. To faciliate the use of these species as bioindicators requires the development of tools for rapidly and ...effectively assessing individual health. Here, we collected 104 blood samples from 69 loggerhead sea turtles, Caretta caretta, undergoing rehabilitation to determine the connection between health status, the activity of B-esterases, and other biochemical parameters. To determine the optimal assay protocol for B-esterases, we measured the activity and kinetics of cholinesterases-(ChEs) and carboxylesterases (CEs) using 3 and 5 commercial substrates, respectively, at different assay conditions. IC50 values for the activity of B-esterases were calculated within a concentration range for model pesticide inhibitors. Turtles’ health status was determined via routine veterinary procedures. During rehabilitation (which was associated with improving health status), we observed a decrease in the activity of most enzymes (especially in acetylcholinesterase) alongside an increase in CE when using p-nitrophenyl acetate as a substrate. As such, it is possible that the activity rates of plasmatic B-esterases could serve as an indicator of health status. There is also high potential that B-esterases could be specifically sensitive to marine pollutants although to further validate this would require future studies to specifically correlate B-esterarse activities to pollutant concentrations in blood or excreta.
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•Loggerhead turtles undergoing rehabilitation exhibited a decrease in plasmatic AChE activity.•Increases in pNPA-CE activity in loggerhead turtles may be linked to immune-system modulation.•Higher hydrolysis rates on plasmatic B-esterase measurements in marine turtles were seen at pH = 8.•Gas embolism significantly affected αNB-CE measurements in marine turtles.
The Mediterranean Sea has been described as one of the most affected areas by marine litter in the world. Although effects on organisms from marine plastic litter ingestion have been investigated in ...several oceanic areas, there is still a lack of information from the Mediterranean Sea. The main objectives of this paper are to review current knowledge on the impact of marine litter on Mediterranean biodiversity, to define selection criteria for choosing marine organisms suitable for use as bioindicator species, and to propose a methodological approach to assessing the harm related to marine litter ingestion in several Mediterranean habitats and sub-regions. A new integrated monitoring tool that would provide the information necessary to design and implement future mitigation actions in the Mediterranean basin is proposed.
According to bibliographic research and statistical analysis on current knowledge of marine litter ingestion, the area of the Mediterranean most studied, in terms of number of species and papers in the Mediterranean Sea is the western sub-area as well as demersal (32.9%) and pelagic (27.7%) amongst habitats.
Applying ecological and biological criteria to the most threatened species obtained by statistical analysis, bioindicator species for different habitats and monitoring scale were selected. A threefold approach, simultaneously measuring the presence and effects of plastic, can provide the actual harm and sub-lethal effects to organisms caused by marine litter ingestion. The research revealed gaps in knowledge, and this paper suggests measures to close the gap. This and the selection of appropriate bioindicator species would represent a step forward for marine litter risk assessment, and the implementation of future actions and mitigation measures for specific Mediterranean areas, habitats and species affected by marine litter ingestion.
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•Marine litter ingestion represents a serious harm to Mediterranean biodiversity.•A bibliographic research and statistics identified the most affected habitat/species by marine litter ingestion in the Med.•The identification of suitable bioindicators is necessary to address the effects of marine litter on marine fauna and habitat.•To assess the harm by marine litter ingestion is necessary to quantify its presence and ecotoxicological effects.
Selection of suitable bioindicators of marine litter ingestion and the simultaneous quantification of its presence and ecotoxicological effects is recommended in order to monitor the impact on Mediterranean fauna and habitats.
•Very low concentrations offloating macro and microplastics found around Antarctica.•Mean densities of 0.03 macrolitter items·km−2 and 187.6 microplastics·km−2.•Plastic densities are one order of ...magnitude lower than in adjacent temperate waters.•The Subtropical Front seems to be a barrier to the dispersal of drifting plastics.
While macroplastics have been washing up on Southern Ocean islands for decades and microplastics have been found in seabirds from the region since 1960, there are still relatively few quantitative data on the amount of plastic pollution, especially with regard to floating plastics, at high southern latitudes. We present a baseline estimate of the abundance of floating plastics around the Southern Ocean from a survey of floating macro-, meso- and microplastic pollution conducted during the Antarctic Circumnavigation Expedition in 2016/17. A total of 40 net trawls and 626 h of observation were performed during this survey. Of these, 33 net samples and 552 h of observation were made in polar waters south of the Subtropical Front (STF). Only 5 microplastics and 17 macrolitter items were observed south of the STF, confirming the Southern Ocean as the region with the lowest concentrations of plastic pollution globally. The mean concentrations of floating macrolitter (0.02–0.03 items·km−2) and small plastic fragments (188 ± 589 particles·km−2) south of the STF were one order of magnitude lower than in adjacent temperate waters north of the STF, which suggests that the STF acts as a barrier to the southward transport of floating debris. Despite their much lower density, the mass of macroplastics was similar to that of floating microplastics in the Southern Ocean.
Accurate and automated identification of marine litter on the seafloor is crucial due to its detrimental effects on marine ecosystems. While advancements in underwater imaging have facilitated this ...task, the significant human involvement required in traditional approaches necessitates the development of more efficient and cost-effective solutions. This study presents an efficient zero-shot segmentation framework based on Segment-Anything (SAM) guided by Interpretable Contrastive Language–Image Pre-training (iCLIP) for identifying and segmenting eight common seafloor litter categories in realistic underwater environments without model training. The framework supports prompt input by design, which allows it to transfer its zero-shot capabilities to new types of marine litter. To further improve the framework’s performance, two additional components were incorporated: an underwater image enhancement model that addresses the degraded image quality common in underwater environments, and a mask post-processing algorithm that reduces noise masks generated by the framework. The recorded mean intersection over union (mIOU) of 69.9% on the testing dataset suggested that zero-shot approaches have the potential to become a valuable technique for automatically detecting marine litter during surveys and enabling continuous and accurate litter monitoring.
•We introduce a zero-shot marine litter segmentation framework.•An underwater image enhancement algorithm was applied to improve the dataset quality.•The framework achieves a test mIOU of 69.9% for eight common marine litter.•We perform detailed analysis of the model’s robustness against complex background noise.•We demonstrate the potential of zero-shot approach for automated marine litter monitoring.
This study reports for the first time the ingestion of meso- (5.01–25 mm) and microplastics (1 μm–5 mm) by the sea anemone Bunodosoma cangicum, the most abundant actiniarian species on the Amazon ...coast. At three sites on the coast of Pará, Brazil, anemones were collected from beachrocks in the intertidal zone (30 at each site), measured (pedal disc diameter, mm) and weighed (wet weight, g). The contents of the gastrovascular cavity were extracted and analyzed under a stereoscope. The recovered plastic particles were characterized by Fourier Transform Infrared (FTIR) spectroscopy. Overall, 139 microplastic and 2 mesoplastic items were identified in 68 individuals (75.6%) among the 90 examined, with a mean of 1.6 (±1.5) items per individual. Plastic fibers comprised about 84% of the ingested plastics, followed by fragments (∼12%) and films (∼4%). Particle diameters ranged from 0.10 to 9.17 mm (1.57 ± 1.23 mm). A weak positive correlation was found between the weight of anemones and the number of plastic particles in the gastrovascular cavity (p = 0.03) and between the number of prey items and the number of plastic particles in the gastrovascular cavity (p < 0.01). The main polymers identified by FTIR analysis were polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyurethane (PU), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polystyrene (PS) and rayon. Sea anemones ingested significantly more plastic debris at the most urbanized and populous sampling sites. This study provides the first evidence of microplastics contamination of marine invertebrates from the Amazon coast. Abundant species such as B. cangicum have the potential to monitor the levels of plastic contamination in the region. Our results support this potential, as the species showed a high frequency of plastic ingestion and allowed detection of plastic contamination even in the best-preserved area where anemones were collected.
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•This is the first evidence of microplastic ingestion by Amazon invertebrates.•Plastic ingestion was correlated with anemones weight and number of ingested prey.•The polymers identified by FTIR method were PET, PP, PA, PU, PE, ABS, PS and Rayon.•Sea anemones ingested more plastic debris at the most populous sites.•B. cangicum is a potential indicator of plastic pollution at the Amazon coast.
Bunodosoma cangicum showed a high frequency of microplastic ingestion and was able to indicate contamination even in a conservation unit, supporting its potential as a biomonitor.
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