Antibiotic resistance has become an important focus of research in the aquaculture environment. However, few studies have evaluated antibiotic resistance during the seedling period in marine fish cage-culture areas. In this study, culture-dependent methods and quantitative polymerase chain reaction were used to identify and detect cultivable heterotrophic antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs), respectively, during the seedling period in a marine fish cage-culture areas of Hainan, China. Bacterial resistance to amoxicillin, erythromycin, and gentamicin was generally high (average on 27.67%, 23.61% and 37.32%, respectively), whereas resistance to furazolidone and nitrofurantoin was generally low (average on 0.14% and 7.425%). Alteromonas (32.72%) and Vibrio (24.77%) were the dominant genus of ARB. Most ARB were opportunistic pathogens, belonging to the phylum Proteobacteria (96.02%). The abundance of sul family genes was higher than that of tet family genes. Overall, the abundance of ARGs and the resistance rates in HW was highest.

Plastic pollution is a major ecological catastrophe that endangers vulnerable species. Small plastic fragments and filaments enter the food web in the ocean threatening marine species health. Here microplastics between 0.5 and 5 mm were quantified from eight beaches of southwest Bay of Biscay (Spain) within Natura-2000 Special Protection Areas for birds. Sand samples were taken using a randomized quadrat-based protocol. Between 145 and 382 particles per kg of dry sand were found, which is relatively high in comparison with other European beaches. Microfibers were more abundant than microplastics. PERMANOVA revealed a significant effect of the beach location (inside versus outside the estuary). Open beaches contained a higher microplastic density than sheltered ones suggesting that many beached microplastics come from the ocean. Birds are at risk in the studied protected spaces as revealed from high concentrations of fibres in depositions of European shag and gulls.

The distribution of floating litter in marine waters, influenced by currents and wind drag, often determines the dispersal of its encrusting fauna. In the present paper, we observed for the first time the colonization of rafting floats from abandoned, lost or derelict fishing gears (ALDFG) by the four protected deep-sea species: Errina aspera, Desmophyllum pertusum, Madrepora oculata Pachylasma giganteum.Overall, 41 floats, colonized by deep benthic species, were found stranded on the shore of the Sicilian coast of the Strait of Messina, between 2016 and 2019. Species composition, number and occurrence of colonizing organisms were analyzed. On the basis of the species composition (the association between E. aspera, P. giganteum and Megabalanus tulipiformis), the knowledge on their ecology, biogeography, path of local currents, it was possible to define that the area of origin of the most part of these fishing net floats was the Strait of Messina.

Seabirds have been widely used to monitor marine debris by the analysis of plastic ingestion. With the aim of obtaining the first data on ingestion of plastics by different seabird species in the Bay of Biscay and evaluating their suitability as biomonitors of plastic pollution in this area, a total of 159 seabirds of fifteen species were analyzed. Plastics were found in 26 birds (16% of the individuals) of nine species (60% of the species). Frequency of occurrence of plastics varied between 0% (Razorbill) and 100% (species of the family Procellariidae). Considering several criteria to assess their suitability as biomonitors of plastic pollution (frequency of occurrence of plastic ingestion, species abundances and stranding occurrence in the Bay of Biscay), the Common Guillemot and the Atlantic Puffin seem the most promising candidates. This study provides the first data on plastic ingestion in seabirds of the Bay of Biscay.

We investigated the distributions of the artificial radionuclides ¹³⁷Cs, ²³⁹⁺²⁴⁰Pu, and ⁹⁰Sr in the various marine products around Korean Peninsula collected in 2015–2017. The activities of ¹³⁷Cs, ²³⁹⁺²⁴⁰Pu, and ⁹⁰Sr were in the ranges of 12.2–258.4 mBq kg⁻¹, 0.014–1.879 mBq kg⁻¹, and 11.3–18.3 mBq kg⁻¹, respectively. The higher ²³⁹⁺²⁴⁰Pu (a factor of 10–50) relative to fishes were observed in mollusks. ¹³⁷Cs in fishes were significantly enriched with growths. The calculated concentration factors (CFs) of ¹³⁷Cs, ²³⁹⁺²⁴⁰Pu, and ⁹⁰Sr in marine products were 7–143, 3–407, and 15–25, respectively. Overall, no noticeable artificial radioactivity was detected in marine organisms when comparing these results with previous data reported before the Fukushima nuclear accident and recommended CF values. The annual effective doses of ¹³⁷Cs, ²³⁹⁺²⁴⁰Pu, and ⁹⁰Sr by seafood consumption in South Korea were estimated to be 1.1 × 10⁻⁴, 1.6 × 10⁻⁵ and, 2.9 × 10⁻⁵ mSv yr⁻¹, respectively, which is insignificant relative to that of natural radionuclides.

Mussels pose health risks to consumers through accumulation of trace metals from the ocean. Saldanha Bay, South Africa, has heavy industry and international shipping, creating concerns over pollution levels for aquaculture facilities. Samples of C. meridionalis and M. galloprovincialis were collected from mussel rafts over two-years and analysed for trace metal content using Inductively Coupled Plasma Mass Spectrometry. Aluminium, Cr, Fe, Zn, Cd and Pb were higher in M. galloprovincialis, while C. meridionalis accumulated more Cu and Mn. Temporal fluctuations occurred for Fe and As concentrations in C. meridionalis, and Fe, As, Hg and Pb in M. galloprovincialis. Arsenic exceeded South African regulatory limits (3 mg/kg) once in each species (max = 3.4 mg/kg w.w.). Lead concentrations in M. galloprovincialis were within EU regulatory limits for bivalves (1.5 mg/kg) but exceeded SA regulatory limits for fish (0.5 mg/kg) four times. Overall, farmed mussels from Saldanha Bay were determined to be safe for human consumption.

With the status as the world's top contributor of marine plastic debris, Indonesia has committed to reduce marine plastic debris up to 70% in 2025 by establishing the National Action Plan (NAP) on Marine Debris. The high amount of marine plastic debris as a result of transport and accumulation become a complex issue in Indonesia due to its ocean-atmospheric circulation, high population of coastal communities, and marine activities. Based on our findings, there are gap of publications related to marine debris in Indonesia that had been already published. Marine debris is ubiquitous and transboundary, as they were found in marine environment and transported by currents to various direction including uninhabited islands, thus, we propose more comprehensive future research about the impact of marine debris on ecosystem (e.g. biological impact of organisms in the water column, ecological alteration in distribution pattern, and invasive species), human health, and economic loss.

Foreshore litter data from a UK citizen-science programme, combined with OSPAR data, were analysed for possible spatial patterns around Scottish and North Sea coastlines. Loading distributions were positively skewed, and statistics commensurate with such distributions were used. When considering coast type, litter loadings on Scottish harbour and river foreshores were influenced by local litter sources. When considering exposure to the predominant westerly winds over Scotland, litter loadings on the west coast (i.e. predominant onshore winds) were greater on foreshores on open coasts compared to those within embayments. The opposite was true for the Scottish east coast (i.e. predominantly offshore winds). The north east coast of the UK appeared to have an organised pattern of plastic litter loading, increasing in magnitude (median) and spread (inter quartile range) in the direction of the coastal flow. Four other coastal segments with similar patterns were suggested from the west of Scotland to Denmark.

This study focuses on the ecological health assessment of Chilika, a shallow lagoon present in east coast of India, through nutrient stoichiometry and trophic state index (TSI). Multivariate statistical analysis such as ANOVA, Pearson's correlation, Principal Component Analysis (PCA), and Discriminant Analysis (DA) were employed for data interpretation. Nutrient stoichiometry revealed that the Chilika Lagoon experiences phosphorus limitation with regard to nitrogen and silicate (N:P:Si = 16:1:16) throughout the study period. As per the computed TSI values, the southern sector (SS), central sector (CS), and outer channel (OC) were assigned with a mesotrophic status, whereas the northern sector (NS) was assigned with the eutrophic status. From PCA, total nitrogen was found to be negatively correlated with salinity and positively correlated with silicate, thus indicating that the major source of nitrogen in the lagoon was freshwater ingress by rivers with high silicate content. DA indicated that it was successful in discriminating the groups as predicted.