Global Meta-Analysis and Review of Microplastic in Marine Copepods.

Plastic pollution has spread through all parts of the marine environment, representing a significant threat to species and ecosystems. This study investigates the role of copepods as widespread microplastic reservoirs in the marine environment, by performing, a systematic review, meta-analysis, and semiquantitative analysis of scientific articles focusing on the interaction between copepods and microplastics under field conditions. Our findings indicate that despite uniformly low ingestion of microplastics across different marine layers and geographical areas, with a slight uptake in neustonic copepods, copepods might constitute one of the largest marine microplastic reservoirs. This phenomenon is attributed more to their vast abundance than to average microplastic ingestion values. In this article, a framework for data analysis and reporting is proposed to facilitate future large-scale evaluations and modelling of their extent and impact on plastic and carbon cycles. These insights place copepods at the forefront of the marine plastic cycle, possibly affecting plastic distribution, and bioavailability, thereby opening new pathways for understanding the complex dynamics of microplastics in marine ecosystems.

The hyperbenthic environment: A forgotten habitat for plastic pollution.

This study investigates the abundances and composition of microplastics (MP) among the shallow layers of a coastal Mediterranean Marine Protected Area (Cabrera MPA), seafloor sediments, hyperbenthic environment, and the water column. The mid waters samples were collected mid-way between the sea surface and the seafloor and hyperbenthic samples at the water layer adjacent to the seafloor. Sampling was carried out on patchiness seafloor of Posidonia oceanica meadows. The seafloor sediments showed a mean abundance of 378,769.20 ± 508,109.11 MPs/m3, three orders of magnitude higher than the hyperbenthic (209.17 ± 117.07 MPs/m3), and the mid waters layer (106.48 ± 107.17 MPs/m3). An increasing vertical gradient in MP abundances, mainly composed of fibers was observed. Fibers were made-up mainly of polystyrene (PS, 25 %), expanded polystyrene (EPS, 18 %) and cellulose acetate (CA, 16 %). The results stress the need to increase efforts to find solutions to mitigate fiber pollution in the marine environment.

Breaking the paradigm: Marine sediments hold two-fold microplastics than sea surface waters and are dominated by fibers.

We conducted one of the first studies to integrate the quantification and characterization of microplastics (MPs), including fibers, in different habitats (sea surface, seafloor and beach sediments) of a coastal Mediterranean marine protected area, analyzing their ingestion in several marine species. The objectives of the study were to evaluate the distribution of MPs according to shape and polymer, to assess the contribution of fibers to local plastic pollution and to evaluate their ingestion in fish and invertebrates species that inhabit the study area (Pagrus pagrus, Serranus scriba, Spondyliosoma cantharus, Diplodus vulgaris, Oblada melanura, Holothuria forskalii, Holothuria tubularis, Holothuria polis, Arbacia lixula, Paracentrotus lividus, Modiolus barbatus, Mytilus galloprovincialis and Arca noae). A total of 111 environmental samples were analyzed. The mean abundance of MPs (excluding fibers) quantified in beach sediments (13,418.86 ± 28,787.99 MPs/m2) was two orders of magnitude higher than that found in seafloor sediments (76.92 ± 108.84 MPs/m2), which in turn was two orders of magnitude higher than sea surface samples (0.17 ± 0.39 MPs/m2). The fibers were the most abundant shape of MPs identified in all habitats. Variability in MPs ingestion was detected between species, with ingestion rates ranging from 43 % to 100 % for general MPs and ranging from 7 % to 100 % for fibers. The highest ingestion was observed in Holoturians, representing suitable bioindicators for plastic pollution. The composition of the polymer varies weakly depending on habitats and biota, but the result is strongly correlated with the morphology of the plastic. Fibers were mainly composed of cellulose acetate (29 %), styrofoam of polystyrene (18 %), and filaments, films and fragments of polyethylene and polypropylene. The results highlighted the need to expand integrated approaches to effectively study marine plastic pollution and to undertake efficient actions to limit the input of plastics, particularly fibers, into the marine environment.

Marine plastics in Mediterranean islands: Evaluating the distribution and composition of plastic pollution in the surface waters along four islands of the Western Sea Basin.

To study the spatial distribution of sea surface plastics in marine protected and non-protected areas, 65 sea surface trawls were carried out using a Hydro-bios manta net coupled with a 335-µm mesh. A total of 19 sampling sites along the coastal waters of Mallorca, the "Parque Nacional Marítimo-Terrestre del Archipiélago de Cabrera" and Menorca in the Balearic Islands as well as along coastal waters of The Natural Park of Columbretes Islands (NW Mediterranean Sea) were sampled. A total of 10,637 plastic items were identified and a subset of these items was categorized by shape, color, size and polymer composition. Plastic particles were found at each sampling site and in all samples. No microscale nor mesoscale variability in floating marine plastics abundance (particles/m2) was encountered throughout the study area where similar values were found in protected areas with no local land-based contamination sources, such as Columbretes [0.04 (±0.03) particles/m2], and in high anthropized areas, such as the island of Mallorca [0.04 (±0.07) particles/m2]. However, differences were found in characteristics of plastic items (shape, polymer, and size range), with the protected area of Columbretes characterized by the presence of the highest density of very small plastic items composed mainly of fragments (93%). Quantified plastics from the marine environment were composed mainly of polyethylene (PE, 63.3%), polypropylene (PP; 24.9%), polycarbonate (PC; 4.6%) and polystyrene (PS, 3.3%). The polymer composition showed a homogenous composition between islands and differences were detected only amongst Columbretes and the other islands. Results from this study provide further evidence of the ubiquity of plastics in the marine environment and highlight that remote and protected areas, such as Columbretes, are not exempt from plastic pollution, but receptor areas for small and aged floating plastics composed mainly by fragments, which might have potentially harmful effects on protected ecosystems.

Neustonic microplastics and zooplankton in coastal waters of Cabrera Marine Protected Area (Western Mediterranean Sea).

The high abundance of microplastics in marine environments is becoming a growing threat for Marine Protected Areas (MPAs). Recent studies have identified microplastics (MP) as having multiple effects on biota, and it is of special interest to highlight their effects on zooplanktonic organisms. These organisms play a key role on local food web structures and there is a need to better understand the accumulation of MPs and associated contaminants within the food web. The present study addresses MP distribution and composition within Cabrera MPA as well as its effects on local zooplanktonic community composition. Neustonic microplastic and zooplankton abundance and composition were determined in the shallow coastal waters of Cabrera MPA during the summer season of 2019. Samples were taken using a sea surface manta-net, with a mesh size of 335 µm. MPs were found in all manta trawl samples for a total of 7047 MP with an overall mean abundance (± SD) of 3.52 (± 8.81) items/m3, a value higher than those reported for the majority of Western Mediterranean Sea basins. Qualitative and semi-quantitative analyses of the local zooplankton community suggest that its composition could be sensitive to MP abundances. Although no correlation was found between overall mean abundance of MP and zooplankton, a positive correlation was found between MP abundance and the abundance of the planktonic stage of the foraminifer Rosalina globularis (Tretomphalus). This species seems to be able to use MP for its dispersion. On the other hand, a negative correlation between MP abundance and Copepoda abundance was detected. This work confirms that the coastal zooplankton community composition within the MPA of Cabrera are not exempt from MP pollution and suggests important and complex interactions between MP and zooplankton organisms in coastal waters.

Microplastic intake and enzymatic responses in Mytilus galloprovincialis reared at the vicinities of an aquaculture station.

Aquaculture is a potential source of microplastics (MPs) that could be strong stressors for marine organisms. In this study, we evaluated the effects of MPs derived from aquaculture in antioxidant defences and oxidative stress markers in gills of Mytilus galloprovincialis. Mussels were distributed in three areas with different impacts: inside aquaculture cages, Control 1 (located inside Andratx harbour) and Control 2 (located in a no-anthropized area). Samples were obtained along three different time periods in May (T0), July (T60) and in September (T120). At each sampling period, mussels' biometric measurements were taken, and tissue samples were kept frozen for biochemical determinations and to determine the intake of MPs. An increase in MPs intake was detected throughout the study, and this increase was significantly higher in samples from the aquaculture cages. Similarly, antioxidant enzyme activities (catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase) were significantly higher in samples from cages at T120. Additionally, a similar tendency was observed in glutathione-s-transferase, with a higher activity in the aquaculture cages at T60 and T120. Malondialdehyde and carbonyl protein derivates as a marker of oxidative damage were also measured and samples from aquaculture cages presented higher oxidative stress markers, mainly in T120. In conclusion, living in environments exposed to aquaculture activities at sea may imply a higher intake of MPs which in turn might cause an antioxidant response in M. galloprovincialis which is not enough to avoid oxidative damage.

Impact of the marine litter pollution on the Mediterranean biodiversity: A risk assessment study with focus on the marine protected areas.

In this paper a novel methodology to assess the risk of marine litter (ML) pollution in the Mediterranean Sea is implemented. In this approach, the hazard component is estimated using a state-of-the-art 3D modeling system, which allows the simulation of floating and sinking ML particles; the exposure component is defined from biodiversity estimates; and the vulnerability is related to ML ingestion rates of each species. The results show that the hot-spots for the ML risk concentrate in the coastal regions, and are mainly conditioned by the biodiversity in the region. A dedicated analysis on the marine protected areas shows that the risk therein is controlled by the proximity to ML sources and that their present-day protection levels are not effective in the case of ML pollution. Only a reduction of ML at the sources could reduce the impact of ML pollution in protected areas.

Long-term exposure to virgin and seawater exposed microplastic enriched-diet causes liver oxidative stress and inflammation in gilthead seabream Sparus aurata, Linnaeus 1758.

Plastics accumulation in marine ecosystems has notable ecological implications due to their long persistence, potential ecotoxicity, and ability to adsorb other pollutants or act as vectors of pathogens. The present work aimed to evaluate the physiological response of the gilthead seabream (Sparus aurata) fed for 90 days with a diet enriched with virgin and seawater exposed low-density polyethylene microplastics (LDPE-MPs) (size between 100 and 500 µM), followed by 30 days of depuration, applying oxidative stress and inflammatory markers in liver homogenates. No effects of LDPE-MPs treatments on fish growth were observed throughout this study. A progressive increase in antioxidant enzyme activities was observed throughout the study in both treatments, although this increase was higher in the group treated with seawater exposed MPs. This increase was significantly higher in catalase (CAT), glutathione reductase (GRd), and glutathione-s-transferase (GST) in the seawater exposed MPs group, with respect to the virgin group. In contrast, no significant differences were recorded in superoxide dismutase (SOD) and glutathione peroxidase (GPx) between both groups. Exposure to MPs also caused an increase in the oxidative damage markers (malondialdehyde and carbonyls groups). Myeloperoxidase activity significantly increased because of MPs treatments. After 30 days of depuration, antioxidant, inflammatory enzyme activities and oxidative damage markers returned to values similar to those observed in the control group. In conclusion, MPs exposure induced an increase of antioxidant defences in the liver of S. aurata. However, these elevated antioxidant capabilities were not enough to prevent oxidative damage in the liver since, an increased oxidative damage marker was associated with MPs ingestion. The treatment with seawater exposed MPs caused a more significant antioxidant response (CAT, GRs, and GST). Although after a depuration period of 30 days a tendency to recover the initial values of the biomarkers was observed this does not seem to be time enough for a complete normalization.

Lessons learned from an intercalibration exercise on the quantification and characterisation of microplastic particles in sediment and water samples.

An intercalibration exercise on the characterisation of microplastics in marine sediment and water samples was carried out among five laboratories involved in the implementation of the Marine Strategy Framework Directive (MSFD) in their country. The samples were prepared by mixing cleaned natural sediment and sea water with microplastics sets made of particles of various polymers, shapes and colours. Overall, the errors on total counts were under 25% in absolute value. The risk of non-detection and loss of particles is greater than the risk of contamination during sample analysis. Significant differences are observed among particle types. It appears difficult to obtain reliable and comparable data on the colour of microplastics. A comparison of the errors with regards to the protocols used led to recommend NaCl [1.2 g/cm3] density separation for sediment and one filtering step (200 µm). The operators' experience appears as a key factor for the quality of the results.

Microplastic ingestion by Mullus surmuletus Linnaeus, 1758 fish and its potential for causing oxidative stress.

A total of 417 striped red mullet, Mullus surmuletus, were analyzed to study microplastic ingestion and livers of fish were assessed to study effects of microplastics. Nearly one third (27.30%) of the individuals were quantified to ingest microplastics although there was no evidence of oxidative stress or cellular damage in the liver of fish which had ingested microplastics. A small increase in the activity of glutathione S-transferase (GST) of M. surmuletus was detected which could be suggesting an induction of the detoxification systems but these findings should be tested in laboratory conditions under a controlled diet and known concentration of microplastics. Fish from trammel fisheries, operating closer to land and targeting larger individuals, showed higher mean ingestion values than fish from trawling fisheries, and were related to body size, as microplastics ingested increased with total fish length. Consequently, ingestion values of microplastics were not related to sampling distance from land giving further evidence of the ubiquity of microplastics in the marine environment. Finally, Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that the vast majority of microplastics were filament type and polyethylene terephthalate (PET) was the main identified component.

High levels of microplastic ingestion by the semipelagic fish bogue Boops boops (L.) around the Balearic Islands.

For the first time this study reports on the presence of microplastics (1 nm to <5 mm) in the gastrointestinal tracts of small semipelagic fish (Boops boops) in the Balearic Islands (Mediterranean Sea) from March to May 2014. The results show microplastic ingestion in 68% of full stomach samples with an average of 3.75 items per fish. Only filament type microplastics were observed in B. boops full gastrointestinal tracts. The frequency of occurrence of microplastics was high, with values ranging from 42% to 80%, in comparison to the other ingested items. Spatial variability among locations is high, which suggests that this type of contamination is ubiquitously distributed and originates from multiple sources. The results are important and indirectly provide further evidence of the presence of microplastics, which can be ingested by biota, in the marine environment.

Evidence that inhibitory neurotransmission differs between the proximal and distal segments of guinea-pig taenia caeci.

The effect of atropine (1 microM) and N(G)-nitro-L-arginine (L-NOARG, 10 microM) on electrical field stimulation induced relaxation in proximal and distal segments of guinea-pig taenia caeci in the presence of guanethidine (4 microM) was studied. The frequency-dependent relaxations were lower in proximal than in distal segments both in the presence and in the absence of atropine. The effect of L-NOARG (an inhibitor of nitric oxide (NO) synthase) on relaxation in the presence of atropine depended on the frequency of electrical stimulation and the segment used; the effect of L-NOARG was greater in proximal segments than in distal segments. In the absence of atropine, the inhibitory effect of L-NOARG was the same in both segments at all frequencies tested. This study demonstrates differences between the opposite extremes of guinea-pig taenia caeci in relaxations induced by electrical stimulation. Our data also show a role of NO that is dependent on the integrity of cholinergic transmission.

Multi-centre double-blind trial on the efficacy and safety of sertaconazole 2% cream in comparison with miconazole 2% cream on patients suffering from cutaneous mycoses.

The efficacy and tolerance of 7-chloro-3-[1-(2,4-dichlorophenyl)-2- (1H-imidazol-1-yl)ethoxy-methyl]benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) 2% dermatological cream in two daily applications compared with miconazole 2% cream in two daily applications were studied on 631 patients suffering from superficial cutaneous mycosis (sertaconazole n = 317, miconazole n = 314), in a double-blind, controlled multicentre trial with parallel groups. The therapeutic efficacy was evaluated by clinical assessment of the improvement of the lesion and symptoms, a microscopic test on the presence of hyphae or mycelia in the affected area and a culture test on the presence of active infection. Tolerance and safety were evaluated by a general blood analysis and interrogation of the patient on adverse effects. The rate of clinical cures for both treatments at the end of the follow-up was 95.6% for sertaconazole and 88.1% for miconazole, with the difference being statistically significant. In the comparative analysis of the actuarial curve, it was observed that the patients treated with sertaconazole were cured earlier and in a higher proportion than those treated with miconazole, with the difference being significant. The negative result of the microscope examination and culture test confirmed the superiority of sertaconazole over miconazole, already after 14 days of treatment. At the end of the follow-up, 98.6% of the patients in the sertaconazole group obtained a negative culture test result, as opposed to 91.7% in the miconazole group, with the difference being highly significant.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hepatic angiosarcomas]. / Angiosarcomas hepáticos.

The authors describe three cases of hepatic angiosarcoma diagnosed at postmortem examination, two of them being associated to thorium dioxide. The low incidence of these tumors amongst the general population is commented upon, and an update is made on the factors involved in their appearance, with special mention of thorium dioxide. An analysis of the clinical picture of the disease is undertaken, emphasizing its diagnostic difficulties. A tentative diagnosis can be made on the basis of clear-cut epidemiological data and or the presence of increased radiological density over the liver, spleen and paraaortic lymph nodes in the cases associated to thorium dioxide. Two of the reported patients presented hemolytic anemia, and disseminated intravascular coagulation, respectively; these findings, although nonspecific, may suggest the diagnosis in the presence of a toxic clinical picture or one of the above mentioned factors. The diagnosis should be made by the usual techniques utilized clinically to detect space occupying lesions within the liver. The evolution of such patients is rapidly progressive, with a fatal outcome within three to six months after beginning of symptoms.