Marine litter has adversely affected many marine species. However, information on its impacts on filter-feeding elasmobranchs (such as the whale shark, Rhinocodon typus) is scarce. The Philippines is an essential habitat for whale sharks, and the lack of data on marine litter and its effects on these organisms in the country is concerning. Beached carcasses present opportunities to provide useful data and insights on the issue. On the 7th August 2018, a live whale shark was found beached in Tagum City, the Philippines, and it eventually died. As part of the post-mortem examination, the gastrointestinal tract and gills of the specimen were examined. Marine litter was found lodged in its gills, and pieces of plastic were found inside its stomach (including several pieces likely from local sources within the Philippines). This study is the first documentation of litter in whale sharks from the Philippines, confirming their vulnerability to marine litter.

Several country–wide bans have recently been implemented for microbeads, which are a form of microplastics that are found in our oceans. The effect of the ban on reducing the overall quantity of microplastics in our oceans, however, may not be significant. This paper explores the scientific data related to microbeads to evaluate whether an underlying risk or combination of risks led to the ban, what impact public perception and activism had on this issue, and how this case study may be extrapolated to other emerging issues, such as per- and polyfluoroalkyl substances (PFAS). In some cases, the strategy for communicating with the public and managing the outrage can be equally as important as the regulatory and technical strategies.

The concentration of nine trace elements were analyzed in the different tissue organs of commonly available crabs (Portunus sanguinolentus, Portunus pelagicus and Scylla serrate) and bivalve (Polymesoda erosa) species collected from the Miri coast, Borneo in order to evaluate the potential health risk by consumption of these aquatic organisms. Among the analyzed organs, metal accumulation was higher in the gill tissues. The essential (Cu and Zn) and non-essential (Pb and Cd) elements showed the highest (i.e. Zn) and lowest concentrations (i.e. Cd) in their tissue organs, respectively. The estimated daily intake and hazard indices of all metals in the muscle indicate that the measured values were below the provisional tolerable daily intake suggested by the joint FAO/WHO Expert Committee on Food Additives. Compared to Malaysian and international seafood guideline values the results obtained from the present study are lower than the permissible limits and safe for consumption.

Sundarban along with its networks of rivers, creeks and magnificent mangroves form a unique ecosystem. Acid sulphate soils have developed in this ecosystem under anoxic reducing conditions. In the present study, we have investigated the distribution of acid sulphate soils along with its elemental characterization and possible sources in four reclaimed islands of Indian Sundarban like Maushuni (I1), Canning (I2), Bally (I3) and Kumirmari (I4). Elements show moderate to strong correlation with each other (P < 0.01; P < 0.05). Except Si, Ca and Pb, a higher enrichment factor was observed for K, Cr, Mn, Fe, Ni, Cu and Zn. Geo-accumulation index values of all sampling locations reveal that Cr, Fe, Cu and Zn are in Igₑₒ class 1. The pollution load index value of the reclaimed islands of Indian Sundarban varies between 1.31 and 1.48. The observation of this study could help to strategize policies to mitigate and manage acid sulphate soils in Indian Sundarban.

Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understand the marine debris issue, and to inform the development of solutions that reduce amounts of ALDFG sources and recover existing gear. Substantial work has been and continues to be undertaken around the world to collect data on ALDFG, much of which remains unpublished. To provide a global picture of data on ALDFG, we organized a technical session that brought together seven ALDFG leaders to share their expertise in data collection, retrieval, and awareness-raising. This paper summarizes the technical session to highlight: 1) case studies that feature innovative approaches to ALDFG data collection and retrieval; 2) examples of opportunities to fill data gaps and improve our understanding of wildlife ingestion of and entanglement in ALDFG; and 3) awareness-raising through the development of a publicly accessible global ALDFG database.

Rivers and estuaries are among the main entrances of litter to the marine environment. This study characterizes marine litter deposits in three estuaries of the Gulf of Biscay, assesses its potential impact in estuarine habitats based on expert elucidation, and develops a methodology to estimate the associated environmental risk. Litter was ubiquitous in the estuaries of study, mostly represented by plastic debris and sanitary waste. High marsh communities acted as litter traps, showing significantly higher litter densities than adjacent habitats. The expected impact was valued to be low but different across habitats and possible litter-habitat interactions. The estimated risk was low but different across habitats and estuaries, determined by the probability of encounter and the expected impact. This study contributes to increase the scarce knowledge available on the threat that marine litter poses in estuarine environments and presents a methodology to help identify those habitats under a higher risk.

In a context where the problem of plastic pollution is globally increasing, more studies are needed to assess the real impact in oceanic megafauna. Here, we reported on the incidence of plastic and also retained hooks in two species of commercially exploited pelagic sharks in two ocean basins, the North Atlantic and South Pacific. In the South Pacific, 1.18% of caught blue sharks were observed with plastic debris on their body and 4.82% and with retained hooks, while 0.00% of shortfin makos had plastic debris and 1.76% were recorded with retained hooks. In the North Atlantic, 0.21% of blue sharks had plastic debris and 0.37% of blue, and 0.78% of shortfin makos were observed with retained hooks.

The vaquita (Phocoena sinus) is the world's smallest cetacean and most endangered marine mammal. The species is under threat from illegal fishing activities that take place in the upper Gulf of California (UGC). Artisanal use of gillnets to catch shrimp and poach the endangered totoaba are the primary drivers of vaquita population declines due to bycatch. About 80% of shrimp caught in the UGC is sold to the United States, meaning Americans who consume shrimp may have a direct connection to the plight of the critically endangered vaquita. However, this issue as part of the human dimensions of vaquita conservation has been largely unstudied. Additionally, the majority of Americans are unfamiliar with the vaquita which hinders conservation efforts. This article calls for further research into the human dimensions of vaquita conservation, increased collaboration with fishing communities in the UGC, and connecting seafood sellers and consumers with the vaquita crisis.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous, synthetic anthropogenic chemicals known to infiltrate and persist in biological systems as a result of their stability and bioaccumulation potential. This study investigated 15 PFAS, including short-chain carboxylic and sulfonic acids, and their presence in a threatened herbivore, the West Indian manatee (Trichechus manatus). Seven of the 15 PFAS examined were detected in manatee plasma. Perfluorooctanesulfonic acid (PFOS) (ranging from 0.13 to 166 ng/g ww) and perfluorononanoic acid (PFNA) (ranging from 0.038 to 3.52 ng/g ww) were detected in every manatee plasma sample examined (n = 69), with differing medians across sampling sites in Florida, Crystal River (n = 39), Brevard County (n = 18), Everglades National Park (n = 8), and four samples (n = 4) from Puerto Rico. With an herbivorous diet and long life-span, the manatee provides a new perspective to monitoring PFAS contamination.