This paper provides the first record of ingestion of plastic debris by American lobster, Homarus americanus. Plastics particles, identified as rubber pieces, were found in the stomachs of 3 from 17 individuals of lobsters kept in laboratory conditions. Debris had evidence of cuts, what suggest they were actively consumed.

A floating plastic monitoring program was conducted for two years on a weekly basis in Banderas Bay, Mexico. A total of 94 samples were collected from May 2016 to April 2018 in the southern part of the bay. Half (57%) of them contained plastic debris; 79% of it being <5 mm in length. Polypropylene and Polyethylene were the most abundant polymers, accounting for 45% and 43% of the plastic pieces (pp), respectively. The highest abundance of plastic pieces was found in July 2016, with a maximum of 0.3 pp/m³ found in one sample. The amount of floating plastics was significantly higher in the hurricane season compared to the dry season (p < 0.001). This suggests that rainfall may play a significant role in the offload of plastics from land-based sources into the bay.

Mariculture is known to contribute to oxygen depletion, pH decline and accumulation of nutrients and organic matter in sediments. However, studies on the bacterial vertical distribution of mariculture area are very limited. The bacterial abundance in the non-culture site (3.8 ± 0.8 × 10⁹ copies g⁻¹) was significantly higher than that in the three mariculture sites (1.2 ± 0.2 × 10⁹ copies g⁻¹), and bacterial diversity in the non-culture site was significantly higher than that in fish cage-TF (p < 0.05). The vertical distribution profiles of bacteria in non-culture and oyster culture sites were similar but very different from that of fish cage-TF. In addition, significant downward trends in bacterial abundance and diversity were observed as sediment depth increased (p < 0.05), and the most relevant environmental factors were moisture content, total nitrogen, total organic carbon and carbon/nitrogen. The dominant bacterial phyla in sediment were Proteobacteria, Chloroflexi and Bacteroidetes.

As a new emergence pollutant, microplastic has aroused wide concern from both scholars and the public. In this study, microplastic pollution in surface sediments from 28 stations in Sishili Bay was investigated. The average abundance of microplastics was 499.76 ± 370.07 items/kg (d.w.). Fiber was the majority shape of microplastics (86.37%), followed by film, fragment and pellet. Microplastics <500 μm accounted for more than half of the total microplastics. Eight polymer types including rayon, PE, PP, PA, PET, PS, PMMA and PU were identified. The main component was rayon (58.41%), followed by PP and PET. The microplastic pollution in surface sediments of Sishili Bay is moderate compared with other studies. Microplastic pollution level in port, sewage outfall, estuary and aquaculture area of Sishili Bay was relatively high, which indicated that microplastic pollution was mainly sourced from river and sewage discharge and maritime activities.

Plastic pollution is an omnipresent problem that threatens marine animals through ingestion and entanglement. Marine mammals are no exception to this rule but their interaction with plastic remains understudied in the Mediterranean Sea. Here we highlight this problem by analyzing the stomach contents of 34 individuals from seven odontocete species stranded in Greece. Macroplastic (>5 mm) was found in the stomachs of nine individuals from four species (harbour porpoise Phocoena phocoena, Risso's dolphin Grampus griseus, Cuvier's beaked whale Ziphius cavirostris and sperm whale Physeter macrocephalus) with the highest frequency of occurrence in sperm whales (60%). Gastric blockage from plastic was presumably lethal in three cases, with plastic bags being the most common finding (46%). Plastic ingestion is of particular conservation concern for the endangered Mediterranean sperm whales. A regular examination of stranded cetaceans with a standardised protocol is critical for allowing spatiotemporal comparisons within and across species.

Sinking experiments were conducted using irregularly shaped polyamide (PA), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET) particles sized 6 to 251 μm. Certified PS spheres were used to validate experiments and showed that the effect of particle size on terminal sinking velocity is well reproduced by the method. As expected sinking velocities of irregularly shaped particles were considerably lower than theoretical values for spheres of the same size range calculated via several approximations available in the literature. Despite the influence of particle shape, the dependence of terminal sinking velocity on particle size can reasonably well be described by a quadratic linear regression, with an average determination of 63%. To generalize results we present a model that predicts terminal sinking velocity as a function of particle size and particle excess density over the fluid. Improving the predictive power of this model requires further experiments with a range of particle characteristics.

Analyses of thermotolerant coliform and heterotrophic bacteria as well as Escherichia coli and Vibrio species were carried out on plastic samples and in the surrounding waters of Guanabara Bay to evaluate plastic debris as vehicles of bacterial dispersal. Chemical characterizations of plastics were performed using Fourier transform infrared spectroscopy (FTIR). Plastic debris with high coliform contents were found, while their respective water samples had only low titers. No correlations were observed, however, between the amounts of bacteria and the chemical compositions of the plastic debris. Forty-four bacterial strains were PCR-confirmed as E. coli pathotypes, and 59 strains of Vibrio spp. (with 12 being identified as Vibrio cholerae [6], Vibrio vulnificus [5], and Vibrio mimicus [1]). These findings suggest these plastics can function as a substrate for bacterial biofilms (including pathogens). These debris, in turn, can be dispersed in aquatic environments not otherwise showing recent fecal bacterial contamination.

Polycyclic aromatic hydrocarbons (PAH) have been reported as acetylcholinesterase (AChE) inibitors, although in vitro studies on PAH effects on AChE activity are scarce and have only been performed using electric eel brain extracts. Thus, this study investigated PAH effects on brain AChE activity in a tropical fish species in Southeastern Brazil, mullet (Mugil liza). Mullet specimens were obtained from Guanabara Bay (N = 20), Rio de Janeiro, Brazil. Brain AChE was extracted and exposed to an environmentally relevant concentration of Pyrene, Chrysene, Phenanthrene, and Naphthalene, and PAH metabolites, 2-Naphthol and 1-OH-Pyrene. AChE activity inhibition was observed, although no difference was observed between high- and low- molecular weight PAH. 2-Naphthol was a less potent AChE inhibitor than Naphthalene, albeit non-significantly. Further studies are required, since only one PAH concentration was used herein. Mullet brain extracts seem to be adequate to assess possible neurotoxic PAH effects on fish AChE.

Persistent organic pollutants (POPs) include polychlorinated biphenyls (PCBs) dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), which are resistant to biodegradation and therefore accumulate in the marine environment. In Australia, POPs occur in high concentrations primarily in costal water near farming regions and urban centres. From contaminated sediments and biota, POPs are transferred and biomagnified in larger marine organisms. We quantified POPs concentrations in 57 individuals from ten species of sharks and rays caught in bather-protection gillnets deployed off northern New South Wales, Australia. Polychlorinated biphenyls, DDTs and HCB were detected in all species. For some individuals, concentrations were at levels known to have deleterious sub-lethal effects. Overall, the POP concentrations analysed in this study were comparable to those in similar species from more polluted regions, and may have negative impacts on longer-term health. Future research is warranted to investigate spatio-temporal patterns of species-specific contaminant loads and their implications.

We monitored the post-release survival of little penguins (Eudyptula minor) rehabilitated after the 2011 C/V Rena oil spill in New Zealand to assess the effectiveness of the rehabilitation process. Surveys were conducted over a 23-month period after the spill to assess whether survival differed between rehabilitated and control penguins. Survival probabilities from mark-recapture analyses were lower for both oiled and control penguins in the first six months of the study (monthly probability 0.92) but increased and remained high thereafter (monthly probabilities 0.97–1.0). Importantly, survival did not differ significantly between oiled and control birds throughout the study. Post-release survival of rehabilitated birds was not influenced by the degree of oiling, body mass (at admission or release), blood parameters (admission packed cell volume, total protein or blood glucose) or the duration of captivity. Rehabilitation therefore appeared to successfully reverse the negative effects of oiling on the post-release survival of treated penguins.