To understand the fate of plastic in oceans and the interaction with marine organisms, we investigated the incorporation of (bio)polymers and microplastics in selected benthic foraminiferal species by applying FTIR (Fourier Transform Infrared) microscopy. This experimental methodology has been applied to cultured benthic foraminifera Rosalina globularis, and to in situ foraminifera collected in a plastic remain found buried into superficial sediment in the Mediterranean seafloor, Rosalina bradyi, Textularia bocki and Cibicidoides lobatulus. In vitro foraminifera were treated with bis-(2-ethylhexyl) phthalate (DEHP) molecule to explore its internalization in the cytoplasm. Benthic foraminifera are marine microbial eukaryotes, sediment-dwelling, commonly short-lived and with reproductive cycles which play a central role in global biogeochemical cycles of inorganic and organic compounds. Despite the recent advances and investigations into the occurrence, distribution, and abundance of plastics, including microplastics, in marine environments, there remain relevant knowledge gaps, particularly on their effects on the benthic protists. No study, to our knowledge, has documented the molecular scale effect of plastics on foraminifera.Our analyses revealed three possible ways through which plastic-related molecules and plastic debris can enter a biogeochemical cycle and may affect the ecosystems: 1) foraminifera in situ can grow on plastic remains, namely C. lobatulus, R. bradyi and T. bocki, showing signals of oxidative stress and protein aggregation in comparison with R. globularis cultured in negative control; 2) DEHP can be incorporated in the cytoplasm of calcareous foraminifera, as observed in R. globularis; 3) microplastic debris, identified as epoxy resin, can be found in the cytoplasm and the agglutinated shell of T. bocki.We hypothesize that plastic waste and their associated additives may produce modifications related to the biomineralization process in foraminifera. This effect would be added to those induced by ocean acidification with negative consequences on the foraminiferal biogenic carbon (C) storage capacity.

Contaminant levels are lower in Antarctica than elsewhere in the world because of its low anthropogenic activities. However, the northern region of the Antarctic Peninsula, is close to South America and experiences the greatest anthropogenic pressure in Antarctica. Here, we investigated, in two Antarctic Peninsula islands, intra and interspecific factors that influence the concentrations of 17 trace elements (TEs) in blood and feathers of three penguin species breeding sympatrically in relation to their trophic ecology assessed via a stable isotopic approach (C, N and S). Geographical location, foraging zone (δ¹³C and δ³⁴S) and diet influences the interspecific difference, and sex and maturity stage diet influence the intraspecific difference of Pygoscelis penguins. Penguins from Livingston showed higher values (mean, ng. g⁻¹, dry weight - dw) of Zn (103), Mn (0.3), and Fe (95) than those from King George Island (Zn: 80, Mn: 1.9, and Fe: 11). Gender-related differences were observed, as males showed significantly higher values (mean, ng. g⁻¹, dw) of Rb (3.4) and δ¹⁵N in blood of gentoo, and Ca (1344) in Adélie feathers. Chicks of gentoo and Adélie presented higher Zn, Mg, Ca, and Sr and lower ¹³C values in blood than adults. The highest concentrations (mean, ng. g⁻¹, dw) of Cd (0.2) and Cu (26), and the lowest δ¹⁵N values were found in chinstrap. Geographical, intraspecific (i.e., ontogenetic and gender-related) and interspecific differences in feeding seemed to have influenced TE and stable isotope values in these animals. The TE bioaccumulation by penguins may have also been influenced by natural enrichment in environmental levels of these elements, which seems to be the case for Fe, Zn, and Mn. However, the high level of some of the TEs (Mn, Cd, and Cr) may reflect the increase of local and global human activities.

Microplastic abundances have been studied intensively in the last years in marine and freshwater environments worldwide. Though several articles have been published about the Mediterranean Sea, only few studies about the Black Sea exist. The Black Sea drains into the Mediterranean Sea and may therefore significantly contribute to the Mediterranean marine pollution. So far, only very few articles have been published about micro-, meso- and macroplastic abundances in the Western Black Sea. In order to fill this knowledge gap and to decipher the number of plastics on the water surface, 12 samples were collected from surface waters with a neustonic net (mesh size 200 μm) in the Black Sea close to the Danube Delta and the Romanian shore. Organic matter was digested and plastic particles were isolated by density separation. The results of visual inspection, pyrolysis GC-MS (for microplastics) and ATR-FTIR (for mesoplastics >5 mm) revealed an average concentration of 7 plastic particles/m³, dominated by fibers (∼76%), followed by foils (∼13%) and fragments (∼11%). Only very few spherules were detected. The polymers polypropylene (PP) and polyethylene (PE) dominated which is in line with other studies analyzing surface waters from rivers in Western Europe as well as in China. Statistical analyses show that the plastic concentration close to the mouth of the Danube River was significantly higher than at four nearshore regions along the Romanian and Bulgarian coastline. This could be explained by plastic inputs from the Danube River into the western part of the Black Sea.

Microplastic contamination in ecosystems has emerged as an environmental issue of global significance. This research quantified microplastics in oysters from 22 sites along Taiwan coastlines. In total, 6630 microplastic items were found in 660 oysters of two genera (Crassostrea and Saccostrea). The average content of microplastics was 3.24 ± 1.02 items/g (wet weight), ranging from 0.63 ± 0.52 items/g to 37.94 ± 19.22 items/g. Over half of the microplastics were smaller than 100 μm, and the most common shape was fragments (67%), followed by fibers (29%). The dominant color was transparent (49.76%), followed by black (25.66%). Polymer types were identified using a μRaman microscope, and the major component was polyethylene terephthalate (PET) (69.54%). Microplastic contamination was higher overall in wild than in farmed oysters. In addition, the microplastic content of oysters from northeastern waters was significantly greater than that of other oysters; this result is similar to the findings of previous research on floating marine litter and beach cleaning data. The results indicated that the average content of microplastic in oysters along the Taiwan coastline was similar to that in oysters in adjacent regions. This study suggests that innovative technologies should be implemented for monitoring and removing pollution, tracking marine pollution origins, and improving accountability and that plastic limitation strategies should be strengthened.

Beaches are key attractions for tourism and recreation, and considerable effort is made to keep beaches clean, yet many beaches still have substantial litter loads. Lasting solutions to reduce the amounts of marine litter require an understanding of litter sources. We collected bottles and other single-use containers at 32 sites around the South African coast to infer their sources based on their age and country of manufacture. Bottle densities varied greatly among beaches (8–450 bottles·km⁻¹), depending on proximity to local urban centres and beach cleaning frequency. Most bottles were plastic, despite well-developed recycling initiatives for PET and HDPE bottles in South Africa. Street litter was dominated by bottles made in South Africa (99%), but foreign-manufactured bottles comprised up to 74% of bottles at some beaches, with an increase from urban (4%) through semi-urban (24%) to remote beaches (45%). Most foreign bottles were PET drink bottles from China and other Asian countries, followed by South America and Europe, with little regional variation in the contribution from these sources. This fact, coupled with their recent manufacture dates (mainly <2 years old), indicates that most foreign PET drink bottles are dumped illegally from ships. By comparison, foreign HDPE bottles were more common along the southeast coast of South Africa than along the west coast, consistent with many of these bottles arriving by long-distance drift across the Indian Ocean from southeast Asia. The most common country of origin for these bottles was Indonesia, and most newly-arrived HDPE bottles were 4–6 years old. To tackle beach litter in South Africa we need to greatly reduce plastic leakage from land-based sources, both locally and in southeast Asia, as well as improve measures to prevent the illegal dumping of plastics and other persistent wastes from ships.

Microplastics (MPs) are currently one of the primary marine pollution problems around the world. MPs are distributed throughout the water column, dependent mainly on the density that is given by the polymer type, as well as the location, depth, and velocities of the water flows. This situation allows all aquatic organisms to be exposed to MPs. Furthermore, toxic substances can adhere to the MPs, making the consumption of fish with MPs a risk to human health. The aim of this study was to evaluate and characterize the microplastics present in the gastrointestinal tract of six species of fish which had the highest human consumption in Campeche, Mexico and their relationship with the density of MPs founded. A total of 316 microplastic particles from 240 individuals were found with 1.31 ± 2.59 of microplastics per fish. The results indicate that there are differences (KW–H = 53.14) between the densities of the MPs present in demersal fish (1.41 ± 0.4 g cm⁻³) with respect to the pelagic species (1.04 ± 0.24 g cm⁻³). Likewise, differences were found between fibers, fragments, and pellets present in the studied fish with a pelagic: demersal ratio of 1: 2.4 for all microplastics. The demersal species Haemulon plumierii (n = 40) presented the highest number of MPs with 115 items in total, 73 fibers, and 42 fragments. The results of this research show the first evidence that the density of the material from which microplastics are made play a key role determining their fate in marine fish habitats.

Marine fishes are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, increasing marine pollution. For this study, 324 specimens of Sardina pilchardus from the Canary Islands were analized during a period of 2 years (June 2016 to May 2018). The concentration of 11 metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V and Zn) was determined in each individual using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical analyses were carried out considering the following factors: oceanographic season, maturity of the gonads in the seasons, size of the specimens. Sardina pilchardus specimens captured in the hot season presented higher Ni, Li and Pb levels than the specimens caught in the cold season. Immature specimens had higher concentration in more metals than the mature specimens. This fact may be due to the fact that these specimens require a much higher metabolic rate due to their growth and do not detoxify like mature specimens. Significant differences were found in the concentration of metals in all the analyzes performed.

Pollution by marine litter is raising major concerns due to its potential impact on marine biodiversity and, above all, on endangered mega-fauna species, such as cetaceans and sea turtles. The density and distribution of marine litter and mega-fauna have been traditionally monitored through observer-based methods, yet the advent of new technologies has introduced aerial photography as an alternative monitoring method. However, to integrate results produced by different monitoring techniques and consider the photographic method a viable alternative, this ‘new’ methodology must be validated. This study aims to compare observations obtained from the concurrent application of observer-based and photographic methods during aerial surveys. To do so, a Partenavia P-68 aircraft equipped with an RGB sensor was used to monitor the waters off the Spanish Mediterranean coast along 12 transects (941 km). Over 10000 images were collected and checked manually by a photo-interpreter to detect potential targets, which were classified as floating marine macro-litter, mega-fauna and seabirds. The two methods allowed the detection of items from the three categories and proved equally effective for the detection of cetaceans, sea turtles and large fish on the sea surface. However, the photographic method was more effective for floating litter detection and the observer-based method was more effective for seabird detection. These results provide the first validation of the use of aerial photography to monitor floating litter and mega-fauna over the marine surface.

A multinational demersal longline survey was conducted on the Gulf of Mexico continental shelf over the years 2015 and 2016 to generate a Gulf-wide baseline of polycyclic aromatic hydrocarbon (PAH) concentrations in demersal fishes. Tilefish (Lopholatilus chamaeleonticeps) were sampled in all regions of the Gulf of Mexico for biometrics, bile, and liver. Tilefish liver was also obtained from surveys in the northwest Atlantic Ocean for comparison. Liver tissues (n = 305) were analyzed for PAHs and select alkylated homologs using QuEChERS extractions and gas chromatography tandem mass spectrometry. Bile samples (n = 225) were analyzed for biliary PAH metabolites using high-performance liquid chromatography with fluorescence detection. Spatial comparisons indicate the highest levels of PAH exposure and hepatic accumulation in the north central Gulf of Mexico, with decreasing concentrations moving from the north central Gulf counterclockwise, and an increase on the Yucatán Shelf. Hepatic PAH concentrations were similar between the Gulf of Mexico and the northwest Atlantic, however, Tilefish from the northwest Atlantic had higher concentrations and more frequent detection of carcinogenic high molecular weight PAHs. Overall, results demonstrate that PAH pollution was ubiquitous within the study regions, with recent exposure and hepatic accumulation observed in Tilefish from both the Gulf of Mexico and northwest Atlantic.

Microplastics are emerging contaminants in the marine environment. They enter the ocean in a variety of sizes and shapes, with plastic microfiber being the prevalent form in seawater and in the guts of biota. Most of the laboratory experiments on microplastics has been performed with spheres, so knowledge on the interactions of microfibers and marine organisms is limited. In this study we examined the ingestion of microfibers by the sea anemone Aiptasia pallida using three different types of polymers: nylon, polyester and polypropylene. The polymers were offered to both symbiotic (with algal symbionts) and bleached (without algal symbionts) anemones. The polymers were introduced either alone or mixed with brine shrimp homogenate. We observed a higher percentage of nylon ingestion compared to the other polymers when plastic was offered in the absence of shrimp. In contrast, we observed over 80% of the anemones taking up all types of polymers when the plastics were offered in the presence of shrimp. Retention time differed significantly between symbiotic and bleached anemones with faster egestion in symbiotic anemones. Our results suggest that ingestion of microfibers by sea anemones is dependent both on the type of polymers and on the presence of chemical cues of prey in seawater. The decreased ability of bleached anemones to reject plastic microfiber indicates that the susceptibility of anthozoans to plastic pollution is exacerbated by previous exposure to other stressors. This is particularly concerning given that coral reef ecosystems are facing increases in the frequency and intensity of bleaching events due to ocean warming.