In ocean conditions of low temperature and high pressure, gas can be converted into hydrates, impacting the behavior of plumes from oil and gas blowouts. This study presented and evaluated formulations to parameterize the processes of formation, dissolution, and decomposition of hydrates implemented in a numerical model that simulates the fate of oil and gas releases in deepwater. Comparisons between the model results and available observations showed a good agreement. Numerical experiments were performed to understand the plume behavior with the presence of hydrates from blowouts at different depths. The analysis of the dynamics of the plume composed of water and gas showed that the hydrate formation increases the plume density and reduces its acceleration due to the buoyancy. As expected, the deeper the blowout, the greater the mass of hydrate in the plume and slower its displacement, spending more time to complete the disappearance of the hydrate.

The use of “chemical fingerprinting” or “profiling” has been suggested as a means to identify habitat use by young-of-the-year (YOY) bluefish (Pomatomus saltatrix). In this study, seasonal and interannual trends were examined over a 3-year period of 31 polychlorinated biphenyl (PCB) congeners and 23 chlorinated pesticides in 176 YOY bluefish collected in the Hudson River Estuary, New York State. Principal component analysis identified distinct and coherent clustering of bluefish according to sampling year. Seasonally, PCB patterns were similar among weight classes, regardless of date of capture. Throughout the study period, there was a consistent seasonal shift toward the heavier chlorinated homologs as size increased even though different congeners contributed to the overall PCB profile in Year 3. Unlike PCBs, there was no consistent pesticide accumulation pattern, which varied seasonally and interannually. The results show the first generalized interannual accumulation profiles of organochlorines during the rapid growth stage of age-0 bluefish. As knowledge of temporal changes in different ecosystems improves, this will improve an understanding on how exposure to chemicals in different ecosystems can affect the long-term health of bluefish.

An investigation of microplastic abundance and its characteristics was conducted in Muara Angke Wildlife Reserve, a relic mangrove forest in the Jakarta metropolitan, to contribute to marine microplastics' national data inventory. Microplastics were found in all the stations, with an average of 28.09 ± 10.28 particles per kg of dry sediment (n kg⁻¹). Sediments in the outside mangrove area contained more microplastics than the inside area. Foam form was the most dominant in all the samples and was found more abundant on the outside. More than half of microplastics were of size <1000 μm, and nearly 50% were polystyrenes. This polymer is widely used for food packaging, which is prone to be fragmented. Polypropylene and polyethylene form another 50% of microplastics, which are widely used for textiles and fishing gears. As Jakarta is the largest city in Indonesia, this microplastic dataset may be the benchmark for other mangroves around the country.

Lanthanoids in the southern Gulf of California (GC) seawater are reported for the first time. Lanthanoids showed differences between peninsular and continental coastline, coastal or marine ecosystems, and dry or rainy season. The chondrite-normalized values showed high variability but followed a same pattern. Light lanthanoids were more enriched than heavy ones. Values of ∑Ln and La/Lu were higher in continental than peninsular coastlines, coastal than adjacent marine ecosystems, and rainy than dry season. Differences were related to the lithology and perturbation degree of the ecosystem watersheds. The chondrite-normalized patterns are typical of geological origin. Slightly negative Ce anomaly was related to the low levels of oxygen in water for the oxidation of Ce (III) to Ce (IV) and its posterior scavenging. Negative δEu anomaly is explained by an influx of fluvial and eolian materials from the upper continental, while a positive Eu anomaly related to hydrothermal vent inputs was non-evidenced.

Here, characteristics of marine litter ingested by Pacific bluefin tuna (PBF, Thunnus orientalis) juveniles under captive conditions were investigated. Swimming speeds of PBF juveniles with pseud-ingested polystyrene chips were compared, and mortality due to polystyrene chip ingestion in cultured teleosts (red sea bream, greater amberjack, and white trevally) was examined in the laboratory. Marine litter ingested by the PBF juveniles included mainly microplastics. The body size of dead specimens with ingested marine litter was significantly smaller than that of other dead fish. We suggest that when the PBF juveniles ingested the marine litter, they died due to energy exhaustion within a few days. All the examined species ingested polystyrene chips, but no related mortality was confirmed. These results suggest that only the PBF could not vomit or excrete the ingested marine litter. This study indicates that the marine litter problem significantly affects the aquaculture industry, especially tuna aquaculture.

Indonesia, the world's largest archipelagic country and the fourth most populated nation, has struggled with coastal water pollution in the last decades. With the increasing population in coastal urban cities, more land-based pollutants are transported to the coastal water and adversely affected the tropical ecosystems. This paper provides an overview of anthropogenic pollutant studies in Indonesian coastal water and ecosystems from 1986 to 2021. Nutrients, heavy metals, organic pollutants, and plastic debris are the most-studied contaminants. We found that 82%, 54% and 50% of the studies exceeding nutrients, heavy metals, and organic pollutants standard limit, respectively; thus, indicating poor water quality status in part of Indonesian coastal water. The coral reef ecosystems is found to be the most sensitive to anthropogenic disturbance. The potential effect of climate change, new coastal pollution hotspots in eastern Indonesia, marine anthropogenic sources, legacy/emerging pollutants, and the need for research related to the biological contamination, are discussed for future opportunities.

The δ¹³C, δ¹⁵N and C/N ratio of the particulate organic matter (POM) in western Guangdong waters were determined to evaluate the impacts of the coastal currents on the POM in spring and summer. The predominance of photosynthetic organic matter in the nearshore was triggered by nutrients brought by the coastal currents in spring and summer, while the proportion of terrestrial organic matter in the offshore was very high in spring but low in summer. In spring, the weaker and narrower coastal currents carried insufficient nutrients (phosphate deficiency) to the offshore and prohibited phytoplankton production. This scenario contributes to the dominance of terrestrial organic matter transported by the cyclonic circulation beyond the coastal currents in the offshore in spring. The Bayesian mixing model reveals that the proportion of terrestrial organic matter (with 75.8% of C₃ plants) in the offshore was higher in spring than in summer (with 33.7% of C₃ plants).

Microplastics (MPs) can be defined as small pieces of plastics that are less than five millimetres in diameter. MPs can be consumed and may be accumulated by filter-feeding organisms such as mussels. Therefore, this study aimed to determine the acute effects of different types, sizes and concentrations of artificially synthesized MPs on the mortality rate and MP accumulation of the green mussel Perna viridis. The samples were exposed to 66, 333, 666, and 1333 items/L of small MPs (<30 μm), medium MPs (30–300 μm), and large MPs (300–1000 μm) polystyrene (PS), polypropylene (PP), and polybutylene succinate (PBS) for 96 h. MPs accumulation in the soft tissue of mussels and mortality effects from MPs ingestion were assessed. There was no mortality observed in the control group. Small PP particles can lead to more mortality than PS and PBS particles of the same size. However, medium- and large PS caused a higher mortality percentage than the same size particles of PP and PBS. Large PS, PP, and PBS showed higher mortality potential than other sizes. MPs largely accumulated in the soft tissues rather than in gill tissues following the 96-hour exposure period. Increased accumulation of the three types of MPs was accompanied by an increase in the percentage of mussel mortality. The study highlights how particle size and type are key factors in plastic particulate toxicity.

The distribution of small (0.5–2 mm, S-MPs) and large (2–5 mm, L-MPs) microplastics and mesoplastic particles in 51 samples of surface beach sands at 7 locations along the southern shore of the Baltic Sea was investigated. MPs particles (3267 in total) were found at all the sites and in all the beach zones. The bulk mean MPs (0.5–5 mm) contamination is 68 ± 117 (median 33) items/kg DW (n = 51). The results were confirmed by μ-Raman spectroscopy analysis. National park areas did not differ substantially from other beaches. Expanded polystyrene fragments accounted for about 38% of the total collected particles. Fibres were the predominant type of MPs (55%). The highest contamination was found within the current wrack line (60.1 ± 36.6 items/kg DW of S-MPs). A consistent picture for S-MPs was observed at the beach face, where the mean values in different locations varied between 21.0 and 58.1 items/kg DW, with a bulk mean of 30.4 ± 13.7 items/kg DW.