Repeated reports of microplastic pollution in the marine pinniped diet have emerged in the last years. However, only few studies address the drivers of microplastics presence and the potential implications for monitoring microplastic pollution in the ocean. This study monitored their in the scats (N = 205) of four pinniped species/subspecies at five different locations in the southern Pacific Ocean (Peru and Chile). Samples from all rookeries contained microplastics, and overall, 68% of the examined scats contained fragments/fibers, mostly blue colored. We confirmed that 81.5% of the fragments/fibers were anthropogenic in origin , but only 30% were polymers. Scats from Juan Fernández Archipelago presented higher microplastic concentrations than continental rookeries. Also, the common diet in each location may influence the levels found in the samples. This study presents a useful non-invasive technique to track plastic pollution in top predator diets as bioindicators for future surveillance/management plans applied to different location.

The heavy metal pollution status of oyster reefs has been assessed with respect to ten metals pollutants in seawater, sediments, and tissues of above two oysters (soft tissues and shells) for assessing the pollution status in a short food chain in Hab River Delta. The results showed that heavy metals accumulated in M. bilineata were higher than those in M. cuttackensis. Simultaneously, the population of M. bilineata species has been ironically decreasing as a results of high pollution. The determined concentrations revealed a significant differences in their profiles among sediments, seawater and bioaccumulation in tissues and shells of two native oysters. The present study also compared these metal concentrations with national and international database by applying different pollution indices. Heavy metals in all samples were above the national environmental quality standards (NEQS-Pakistan). High level of pollution with an alarming condition of Hab River Delta need more attention for coastal management.

The Pestalotiopsis sp. genus comprises filamentous fungi whose species present both pathogenic and clinical-industrial importance. The cultivation and production of bivalve molluscs in regions of Rio de Janeiro is lucrative both artisanally and industrially, as the climate, geography and water quality favor the practice of this activity throughout the year at reduced costs, making the region competitive in the national market. The aim of this study was to isolate and identify filamentous fungi associated with the internal tissue anatomy of bivalve molluscs (Perna perna) from mariculture farms. Samples collected from BEMAR marine farms were dissected and transferred to 1% hypochlorite, washed in sterile distilled water and sown on Petri dishes containing potato dextrose agar (BDA). After four days, a white colony, displaying vigorous mycelium, cotton-like with abundant sporulation and black conidia masses was isolated. Observations concerning vegetative and reproductive structures were performed by microcultures stained with Amann's Lactophenol andCotton Blue. Micromorphology analyses indicated spindle and septated conidia, with two to three apical filiform appendages and a short basal pedicel. The result indicates that bivalve mollusks may be bioindicators for the presence of Pestalotiopsis sp; associated with water transport, possibly due to diluted sediments in the medium. No infectious processes or lesions in the processed material were observed. This is, to the best of our knowledge, the first report of Pestalotiopsis sp; in Perna perna mytilids.

Human waste is a global concern, and volumes are growing rapidly. For opportunistic species, like many birds, urban waste offers alternative food which in turn may lead to plastic ingestion with potential negative effects. We assessed the incidence of plastics and other marine debris in breeding Kelp Gull (Larus dominicanus) diet at nine colonies located along ~2400 km of coastline from southern Buenos Aires to southern Chubut, Argentina, using regurgitated pellets (n = 2355) and chick stomach content samples (n = 588). Plastics were recorded at all colonies, and incidence varied between 0.0 and 16.2% in adult pellets and 0.0–12.5% in chick stomach content samples, depending on the colony, breeding stage and year. Contrary to our expectation, incidence of debris including plastics in Kelp Gull diet was relatively low despite its opportunistic feeding habits and widespread use of refuse dumps, even at colonies located close (<10 km) to these anthropogenic food subsidies.

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.

Heavy metal assessment and natural radioactivity determination in sediments of North Cyprus (Mediterranean coast) were carried out using different analysis methods. The average activity concentrations (range) of ²²⁶Ra, ²³²Th, and ⁴⁰K were found to be 20.1 (30.6–9.2) Bq kg⁻¹dry weight, 18.4 (26.9–12.4) Bq kg⁻¹dw, and 467.3 (619.9–147.6) Bq kg⁻¹dw, respectively. The average activity concentrations of ²²⁶Ra and ²³²Th in the sediment samples were less than the acceptable limits, whereas the average activity concentration of ⁴⁰K in the sediment samples was higher than the worldwide average concentration. With regard to the studied heavy metals, the corresponding decreasing average concentration orders were found to be Mn > Zn > Cr > Ni > Cu > Pb. The heavy metal concentration values that were determined for sediment samples were compared with the values obtained in other studies. According to contamination indexes, the results (except for Cu in S-9) indicated no significant contaminated area.

Laboratory experiments investigated oxygen dynamics in buried oiled sands sampled from areas impacted by the Macondo spill. Measured oxygen fluxes in oil deposits that were permeable to tidal water ranged from 10⁻³ to 10⁻⁴ μmol/cm²-sec, orders of magnitude higher than fluxes in non-permeable deposits (10⁻⁶ to 10⁻⁷ μmol/cm²-sec). Oxygen dynamics were well described by 1-d models that represent increased oxygen consumption in oiled sands. Experiments demonstrated that when oxygen is present and the oil deposit is permeable to tidal water, biodegradation of alkylated phenanthrenes and dibenzothiophenes proceeded over time scales (i.e., weeks) to have a significant impact on the mass and quality of buried oil. For this biodegradation process to proceed, two independent conditions must be met, a source of oxygenated water has to be present (e.g., tidal flushing in the intertidal zone) and the oiled deposit has to be permeable to water (i.e., pores cannot be completely saturated with oil).

Attention on port waters is increasing since these economically important infrastructures are embedded in the coastal environment and their management needs to be considered in the monitoring programmes of coastal ecosystems. To implement the sustainable development (blue growth) of port areas, a general knowledge on the ongoing processes in their waters needs to be obtained, considering both abiotic and biotic variables. The present study aimed at inspecting the relationships among plankton components to provide insights into the ecology of ports. Seasonal samplings were carried out in three Mediterranean touristic ports where bacterio-, phyto- and zoo-plankton were simultaneously assessed at a large spatial scale and compared with respect to environmental variables and anthropogenic inputs. Factor analysis revealed the effects of load of inland waters, seasonality, water turbulence and hydrocarbon pollution on the planktonic components and zooplankton variability in port sectors characterized by different depths and uses.

Asymmetrical variations in six bilateral morphological characters of 75 specimens of Saurida tumbil obtained from the marine waters of Iraq were assessed. The level of asymmetry in the snout length was highest among the morphological traits examined. Variations in asymmetry in S. tumbil increased with size. These variations are possibly due to chemical contaminants.

The environmental DNA (eDNA) metabarcoding was applied to assess benthic ecological health in the west coast of South Korea by investigating a long-term microbial community change (2015–17). The ecological interaction among microorganisms, from phylum to family level, and their associations to environmental variables across the five regions were highlighted. As part of the study, the available chemistry and toxicological data in the regions during the monitoring periods were incorporated into an integrated sediment triad assessment. The bacterial communities were dominated by Proteobacteria (34.2%), Bacteroidetes (13.8%), and Firmicutes (10.8%). Proteobacteria and Bacteroidetes dominated consistently across regions and years, while Firmicutes and Cyanobacteria significantly varied by region and years (p < 0.05). The abundance of this phylum declined over time with the increasing abundance of Cyanobacteria, indicating their independent interactions to certain environmental changes. Planctomycetes and Gemmatimonadetes linked to some contaminants (ΣPAHs and Cu), implying indicator taxa. Overall, eDNA-based microbial community analysis combined with exposures of contaminants and responses of microorganisms is a promising strategy for the assessment of benthic ecological health in contaminated sediments from coastal waters.