Product Formulation Controls the Impact of Biofouling on Consumer Plastic Photochemical Fate in the Ocean.

The photodegradation rates of floating marine plastics govern their environmental lifetimes, but the controls on this process remain poorly understood. Photodegradation of these materials has so far been studied under ideal conditions in the absence of environmental factors such as biofouling, which may slow photochemical transformation rates through light screening. To investigate this interaction, we incubated different plastics in continuous flow seawater mesocosms to follow (i) the extent of biofilm growth on the samples and (ii) decreases in light transmittance through the samples over time. We used consumer products with high relevance (e.g., shopping bags, water bottles, and packaging materials) and with different formulations, referring to primary polymers (polyethylene (PE) and polyethylene terephthalate (PET)) and inorganic additives (titanium dioxide (TiO2)). The behavior of consumer-relevant formulations was compared to those of pure PE and PET films, revealing that the relative effects of UV- and, to a lesser extent, visible-light screening differ based on the formulation of the product. Pure PE showed greater relative UV-transmittance decreases (Δ = -34% through the entire sample, accounting for biofilm on both sides of the plastic film) than PET (Δ = -20%) and PE products with TiO2 (Δ = < -10%). Our results demonstrate that even with biofouling, photodegradation remains a highly relevant process for the fate of marine plastics. However, we expect photodegradation rates of plastics in the ocean to be slower than those measured in laboratory studies, due to light screening by biofilms, and the specific formulation of plastic products is a key determinant of the extent of this effect.

Applying the extended producer responsibility towards plastic waste in Asian developing countries for reducing marine plastic debris.

The extended producer responsibility (EPR) has been adopted in many countries throughout the world to give producers responsibility to manage their products until the post-consumer stage. On many occasions in developing countries, the system is mostly implemented for electronic waste. However, with the rising concern on the marine plastic issue, developing countries, including those in Asia, have started to apply EPR for package and container waste. In practice, developing countries show significant differences in their EPR implementation compared with developed ones due to contrasting conditions of several factors, including social, economic and technology. This article aims to explore the challenges of developing countries to apply EPR as well as determine possible measures to overcome the challenges. Results show that applying EPR system for plastic waste in developing countries faces many challenges, such as the existence of a market-based collection system of recyclables, high transportation cost, lack of waste collection services in rural areas, a limited number of facilities to manage certain types of plastic waste, insufficient pollution control and free riding and orphan products. The challenges, furthermore, can be minimised by differentiating the responsibility of producers, focusing on rural and remote areas, involving informal sectors, creating joint facilities in recycling parks, expanding waste management collection services, increasing the use of EPR and minimising free riding.

A study on transboundary governance of marine plastic debris-the case of an adjacent waters between China and Taiwan.

This study aimed to construct a transboundary marine governance mechanism in the Kinmen-Xiamen waters through literature review, field survey, in-depth interview, and expert opinion survey. The study finds that monsoons, ocean currents, and tides are the main factors affecting the drift of marine debris in the Xiamen Sea area to the beaches of Kinmen. The marine debris mainly included marine plastic debris (MPD), bamboo, and wood in Kinmen and was documented impacting a variety of species, including the horseshoe crab to marine mammals the IndoPacific dolphin. In addition, the problem of marine micro-plastic pollution is becoming increasingly worrisome and hazardous to rare creatures in the Xiamen Sea area. The pollution sources of MPD in Xiamen Bay included coastal tourism activities, micro-plastic discharged from sewage treatment plants, plastic waste produced by lost and discarded marine aquaculture, and plastic drifting terrestrial waste transported from the Jiulong River Basin. Our results show that microplastic pollution in the Kinmen-Xiamen waters may have a greater impact on marine ecology and the surrounding environment. The relevant transboundary marine governance mechanisms are discussed in this study.

Temporal changes in microalgal biomass and species composition on different plastic polymers in nutrient-enriched microcosm experiments.

Marine plastic debris (MPD) is a potential threat to marine ecosystems, but its function as a vector for the transportation of harmful microalgae and its impact on the habitats of other marine organisms are uncertain. To address this gap in knowledge, we performed month-long experiments in 30 L microcosms that contained plates made of six different plastic polymers (polypropylene [PP], low-density polyethylene [LDPE], high-density polyethylene [HDPE], polyvinyl chloride [PVC], polyethylene terephthalate [PET], and polystyrene [PS]), and examined the time course of changes in planktonic and periphytic microalgae. There were no significant differences in the composition of periphytic microalgae or biomass among the different plastic polymers (p > 0.05). Nutrient depletion decreased the abundance of planktonic microalgae, but increased the biomass of attached periphytic microalgae (p < 0.05). In particular, analysis of the plastic plates showed that the abundance of benthic species that are responsible for harmful algal blooms (HABs), such as Amphidinium operculatum and Coolia monotis, significantly increased over time (days 21-28; p < 0.05). Our findings demonstrated that periphyton species, including benthic microalgae that cause HABs, can easily attach to different types of plastic and potentially spread to different regions and negatively impact these ecosystems. These observations have important implications for understanding the potential role of MPD in the spread of microalgae, including HABs, which pose a significant threat to marine ecosystems.

Influence of paternal factors on plastic ingestion and brominated chemical exposure in East Tropical Atlantic Procellariid chicks.

The presence of plastic debris and organo-brominated compounds in the marine environment poses a concern to wildlife. Plastic can absorb and release chemical compounds, making their ingestion potentially harmful, while chemical compounds have become omnipresent, with a tendency to bioaccumulate in the food web. Seabirds are often used as indicators of marine plastic pollution, yet studies on the exposure of tropical communities to plastic contamination are still scarce. In this study we monitored the amounts of plastics in faeces and organo-brominated compounds ingested/assimilated in feathers by adults and chicks of Cape Verde shearwaters and Bulwer's petrels from Cabo Verde. Anthropogenic pollutants, polybrominated diphenyl ethers (PBDEs), and naturally generated methoxylated-PBDEs (MeO-PBDEs) were among the probed compounds. The frequency of plastic debris ingestion was similar in both species' adults and chicks, although, the characteristics of the ingested plastic differed. Frequency and number of microplastics increased throughout the nestling season for chicks from both species. All species and age groups showed the presence of PBDEs and MeO-PBDEs. Among PBDEs, Bulwer's petrels exhibited higher concentrations than Cape Verde shearwaters, and chicks had higher concentration profiles than adults. Specifically, Bulwer's petrel chicks showed higher concentrations than Cape Verde shearwater chicks. On the contrary, Cape Verde shearwater adults exhibited higher occurrence and concentrations of MeO-PBDEs when compared to Cape Verde shearwater chicks. We found no effect of plastic loadings or loadings of organohalogen contaminants on body condition or size, although harmful effects may be hidden or reveal themselves in a medium- to long-term. Feather samples from both adults and chicks were shown to be useful for comparing intraspecific contamination levels and appear suitable for the long-term assessment of organohalogen contaminants in seabirds. Species-specific foraging and feeding strategies are likely the drivers of the observed variation in organochlorine contamination burdens among seabird species.

Marine debris ingestion by adults and fledglings of Swinhoe's storm petrels in the Republic of Korea.

Procellariiformes are highly vulnerable to marine plastic pollution due to their species-specific life histories. In particular, storm petrels are known to be one of the most vulnerable species with respect to plastic ingestion. In this study, we examined the plastic ingestion by adults and fledglings of Swinhoe's storm petrels on Chilbal Island, one of the largest breeding colonies for this species. During 2013 and 2014, we collected adult and fledgling carcasses and analyzed their stomach contents. The results showed that both adults and juveniles were consuming mostly plastics. Most of the collected Swhinhoe's storm petrels were consuming microplastic, with juveniles consuming a higher average amount of plastic than adults. The type of plastic ingested was more threadlike in adults and fragments in juveniles. In conclusion, the characteristics of ingested plastics differed between adults and juveniles, suggesting that analyzing individual age may be important for monitoring plastic ingestion in the future.

Microalgae colonization and trace element accumulation on the plastisphere of marine plastic debris in Monastir Bay (Eastern Tunisia).

In this study, we examined the toxicity potential of the epiplastic microalgal community that developed on low-density polyethylene (LD-PE) plastic debris found in two distinct regions of the Monastir Bay (Tunisia): the coast exposed to anthropogenic discharges and the open sea in front of the Kuriat Islands. Concentrations of potentially toxic elements (PTEs) accumulated in sediments and plastisphere were compared in order to determine their toxicity potential to biological life. The collected plastispheres were predominantly composed of cyanobacteria, chlorophytes, and diatoms. Diatoms display a relatively high diversity (25 species). At all stations, potentially harmful microalgae (PHM) were more abundant in the plastisphere than in seawater and the coastal zone seems to harbour increased number of potentially harmful cyanobacteria within the plastisphere. At the offshore station S1, the PHM community was dominated by the potentially harmful diatoms belonging to the genus Pseudo-nitzschia. Phormidium sp. was the main potentially harmful cyanobacterium identified in the plastisphere of S1. PTEs concentration in the plastisphere was higher than in sediment and ranking with very high contamination factors at all sites according to the sequence Pb > Cu > Cd > Ni > Zn. The highest accumulation of PTEs in the plastisphere was recorded near harbors and industrial zones with important human interference. This work shows that plastisphere can be a threat to vulnerable species not only because it can contain PHM but also because it can accumulate PTEs.

Plastic pollution in a coral reef climate refuge: Occurrence of anthropogenic debris, microplastics, and plasticizers in the Gulf of Aqaba.

The Gulf of Aqaba in the northern Red Sea, considered a coral reef refuge from the negative effects of climate change, is however being subjected to increasing amounts of plastic contamination. We quantified the levels of benthic plastic debris, microplastics, and plasticizers within the coral reef's surrounding seawater and sediment over time. Our results indicate that the coral reefs of the GoA have relatively lower levels of plastic pollution compared to reefs in other regions. The measured benthic debris in the Red Sea reefs was found to be 0.093 ± 0.091 item/m2 and fell within the reported levels found in other tropical coral reefs, with boating and fishing materials being the most abundant type. Deep mesophotic reefs were found to have significantly higher levels of benthic plastic debris compared to the shallower reefs. Microplastic levels in the surrounding seawater of the reef were 0.516 ± 0.317 microplastics/m3. These concentrations in the reef's surrounding waters are comparable to the levels observed in surface waters from the central Red Sea. The target plasticizers appeared infrequently in samples, and the concentrations for the majority of them were below the level of quantification (LOQ = 14.7 ng/l for water and 14.7 ng/g for sediment). The findings from this study provide a valuable scientific basis for shaping regional policies and implementing management strategies aimed at controlling and mitigating plastic pollution. Such policies can ensure the long-term protection of the reefs in the northern Red Sea, turning them into a secure coral refuge shielded from both global and local anthropogenic stressors.

Plastic debris, persistent organic pollutants and their toxicity impacts in coastal areas in Central Chile.

The chemical components of plastic wastes have made their disposal a major economic, social, and environmental problem worldwide. This study evaluated the acute toxicity and genotoxicity of marine plastic debris on the beaches of Concepción Bay, Central Chile, taken during three periods (spring, summer, and winter). An integrated approach was used, including chemical and toxicological data, using the Microtox® test with Vibrio fischeri and SOS chromotest with Escherichia coli and concentrations of polychlorinated biphenyls (PCBs), Organochlorine Pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The results presented here exclusively include the novel data obtained from the winter campaign, revealing high concentrations of PBDEs (238 ± 521 ng g-1). In addition, the genotoxicity and acute toxicity tests were sensitive for most of the samples studied. This investigation is the first attempt to analyse the toxicity of plastic debris in coastal areas along the Chilean coast.

Sediment-driven plastisphere community assembly on plastic debris in tropical coastal and marine environments.

Coastal habitats have been suggested to serve as a sink for unaccounted plastic debris, i.e., "missing plastic" in the sea, and hence, a hotspot of plastic pollution in the marine and coastal environments. Although the accumulation of plastic debris may pose significant threats to coastal ecosystems, we know little about the fate of these plastic debris and their ecological impacts due to the lack of studies on plastic-microbe interactions in coastal habitats, especially for the tropical marine and coastal environments. In this study, we collected plastic debris from 14 sites consisting of various coastal ecosystems (seagrass meadows, mangrove forests, and beaches), and marine ecosystem (coral reef) around Singapore and characterized the prokaryotic and eukaryotic microbial communities colonized on them. Our results showed that the composition of plastisphere communities in these intertidal ecosystems was predominantly influenced by the sediment than by the plastic materials. Compared with surrounding sediment and seawater, the plastic debris enriched potential plastic degraders, such as Muricauda, Halomonas, and Brevundimonas. The plastic debris was also found to host taxa that play significant roles in biogeochemical cycles (e.g., cyanobacteria, Erythrobacter), hygienically relevant bacteria (e.g., Chryseobacterium, Brevundimonas), and potential pathogens that may negatively impact the health of coastal ecosystems (e.g., Thraustochytriaceae, Labyrinthulaceae, Flavobacterium). Taken together, our study provides valuable insights into the plastic-microbe interactions in tropical coastal and marine ecosystems, highlighting the urgent need for plastisphere studies to understand the fate and ecological impacts of plastic debris accumulated in coastal habitats.

Ocean-based sources of plastic pollution: An overview of the main marine activities in the Peruvian EEZ.

Marine-based activities are a critical source of plastic waste into the ocean. This is particularly important in countries with a competitive fishing industry, such as Peru. Thus, this study aimed to identify and quantify the major flows of plastic waste accumulating in the ocean from ocean-based sources within the Peruvian Economic Exclusive Zone. A material flow analysis was elaborated to analyze the stock of plastic and its release to the ocean by a set of Peruvian fleets, including the fishing industry, merchant vessels, cruises, and boating vessels. Results show that in 2018 between 2715 and 5584 metric tons of plastic waste entered the ocean. The fishing fleet was the most pollutant, representing approximately 97 % of the total. Moreover, fishing gear loss represented the highest single-activity contribution, although other sources, such as plastic packaging and antifouling emissions, have the potential to become vast sources of marine plastic pollution.

Selective attachment of prokaryotes and emergence of potentially pathogenic prokaryotes on four plastic surfaces: Adhesion study in a natural marine environment.

This study employed 16S rRNA metabarcoding to establish the diversity of prokaryotic communities and specific characteristics of potentially pathogenic prokaryotic primary colonizers of four plastic materials (EPS, expanded polystyrene; PE, polyethylene; PP, polypropylene; and PET, polyethylene terephthalate). Bacteria inhabiting plastic and seawater differ; thus, distinct changes in the attached prokaryotic community were observed over an exposure time of 21 days, specifically on Days 3, 6, 9, and 12-21. Frist colonizers were Gammaproteobacteria and Alphaproteobacteria; Bacilli and Clostridia represented secondary colonizers. On Day 3, Pseudoalteromonas had a relative abundance >80 %; whereas, the prevalence of Vibrio spp. (potentially pathogenic prokaryotes) increased rapidly on Days 6 and 9. However, after Day 12, the prevalence of other potential pathogens, namely, Clostridium spp., steadily increased. Despite the diversity of the plastic surfaces, attached prokaryotes changed over time instead of showing similar adherent diversity in all plastic materials.

Microbial pioneers of plastic colonisation in coastal seawaters.

Plastics, when entering the environment, are immediately colonised by microorganisms. This modifies their physico-chemical properties as well as their transport and fate in natural ecosystems, but whom pioneers this colonisation in marine ecosystems? Previous studies have focused on microbial communities that develop on plastics after relatively long incubation periods (i.e., days to months), but very little data is available regarding the earliest stages of colonisation on buoyant plastics in marine waters (i.e., minutes or hours). We conducted a preliminary study where the earliest hours of microbial colonisation on buoyant plastics in marine coastal waters were investigated by field incubations and amplicon sequencing of the prokaryotic and eukaryotic communities. Our results show that members of the Bacteroidetes group pioneer microbial attachment to plastics but, over time, their presence is masked by other groups - Gammaproteobacteria at first and later by Alphaproteobacteria. Interestingly, the eukaryotic community on plastics exposed to sunlight became dominated by phototrophic organisms from the phylum Ochrophyta, diatoms at the start and brown algae towards the end of the three-day incubations. This study defines the pioneering microbial community that colonises plastics immediately when entering coastal marine environments and that may set the seeding Plastisphere of plastics in the oceans.

Seafloor litter generated by coastal and offshore fisheries operations in the South Sea of Korea.

Seafloor litter sources, distribution and density were assessed in a bottom trawl survey of the South Sea around Jeju Island by the Ara-ho training ship of Jeju National University. Samples were taken from 14 transects at a depth range of 60-120 m in areas with sandy and muddy substratum. Generally, mean densities varied from 26.9 items/km2 to 62.4 items/km2 and 104.8 kg/km2 to 370.9 kg/km2. Mean densities of total litter sampled was 46.3 items/km2 and 228.6 kg/km2. Derelict gears were the most common litter items (92 % of total litter) with mean densities of 44.3 items/km2 and 228.1 kg/km2. Gillnets and traps were the most derelict with densities reaching 4.9 items/km2 and 99.2 kg/km2 and 25.0 items/km2 and 89.1 kg/km2 respectively. The results of this study indicate that significant level of pollution in the South Sea are generated from commercial fishing activities and gillnets and traps being high risk derelict gears.

Neustonic microplastics and zooplankton in coastal waters of Cabrera Marine Protected Area (Western Mediterranean Sea).

The high abundance of microplastics in marine environments is becoming a growing threat for Marine Protected Areas (MPAs). Recent studies have identified microplastics (MP) as having multiple effects on biota, and it is of special interest to highlight their effects on zooplanktonic organisms. These organisms play a key role on local food web structures and there is a need to better understand the accumulation of MPs and associated contaminants within the food web. The present study addresses MP distribution and composition within Cabrera MPA as well as its effects on local zooplanktonic community composition. Neustonic microplastic and zooplankton abundance and composition were determined in the shallow coastal waters of Cabrera MPA during the summer season of 2019. Samples were taken using a sea surface manta-net, with a mesh size of 335 µm. MPs were found in all manta trawl samples for a total of 7047 MP with an overall mean abundance (± SD) of 3.52 (± 8.81) items/m3, a value higher than those reported for the majority of Western Mediterranean Sea basins. Qualitative and semi-quantitative analyses of the local zooplankton community suggest that its composition could be sensitive to MP abundances. Although no correlation was found between overall mean abundance of MP and zooplankton, a positive correlation was found between MP abundance and the abundance of the planktonic stage of the foraminifer Rosalina globularis (Tretomphalus). This species seems to be able to use MP for its dispersion. On the other hand, a negative correlation between MP abundance and Copepoda abundance was detected. This work confirms that the coastal zooplankton community composition within the MPA of Cabrera are not exempt from MP pollution and suggests important and complex interactions between MP and zooplankton organisms in coastal waters.

The leatherback turtle (Dermochelys coriacea) and plastics in the Northwest Atlantic ocean: A hazard assessment.

Atlantic leatherback turtles are faced with multiple threats, such as ship strikes, pollution and predation, throughout their annual migratory routes in the Northwest (NW) Atlantic. The risks associated with encounters with floating and submerged plastic debris are currently unknown. This study is a hazard assessment of plastics for this turtle's sub-population, using 2010-2019 data from the national Great Canadian Shoreline Cleanup (GSCS) program, therefore potential exposure, and published evidence on the interactions of plastics and leatherbacks, hence potential effects. The type of plastic items and their abundance along shorelines of three Atlantic Provinces - Nova Scotia (NS), Prince Edward Island (PEI), Newfoundland and Labrador (NL) - were evaluated and compared to plastic items known to interact with leatherbacks. During the 2010-2019 period, a total of 220,590 plastic items were collected from 578 sites, representing 1264 km of shoreline. Plastic bags and rope are in the top ten most common items found on shorelines of NS, PEI, and NL. Pot gear and trap nets are in the top ten for PEI and are the 14th most common plastic item found on all shorelines. Cigarette debris is also commonly found. From the literature, plastic bags, pot gear and trap nets, and rope are known to adversely affect leatherbacks. Assuming that a large proportion of the shoreline debris comes in from the sea, after being in coastal waters for unknown periods, the study shows that such items pose a hazard to leatherbacks through ingestion and entanglement, based on published studies. Evidence is now needed on actual exposure at sea to the most common items to establish the ecological risk of plastics to these turtles in NW Atlantic waters.

Microbial Communities on Plastic Polymers in the Mediterranean Sea.

Plastic particles in the ocean are typically covered with microbial biofilms, but it remains unclear whether distinct microbial communities colonize different polymer types. In this study, we analyzed microbial communities forming biofilms on floating microplastics in a bay of the island of Elba in the Mediterranean Sea. Raman spectroscopy revealed that the plastic particles mainly comprised polyethylene (PE), polypropylene (PP), and polystyrene (PS) of which polyethylene and polypropylene particles were typically brittle and featured cracks. Fluorescence in situ hybridization and imaging by high-resolution microscopy revealed dense microbial biofilms on the polymer surfaces. Amplicon sequencing of the 16S rRNA gene showed that the bacterial communities on all plastic types consisted mainly of the orders Flavobacteriales, Rhodobacterales, Cytophagales, Rickettsiales, Alteromonadales, Chitinophagales, and Oceanospirillales. We found significant differences in the biofilm community composition on PE compared with PP and PS (on OTU and order level), which shows that different microbial communities colonize specific polymer types. Furthermore, the sequencing data also revealed a higher relative abundance of archaeal sequences on PS in comparison with PE or PP. We furthermore found a high occurrence, up to 17% of all sequences, of different hydrocarbon-degrading bacteria on all investigated plastic types. However, their functioning in the plastic-associated biofilm and potential role in plastic degradation needs further assessment.

Colonization of plastic debris by the long-lived precious red coral Corallium rubrum: New insights on the "plastic benefits" paradox.

Seafloor macrolitter is ubiquitous in world's oceans; still, huge knowledge gaps exist on its interactions with benthic biota. We report here the colonization of plastic substrates by the Mediterranean red coral Corallium rubrum (L. 1758), occurring both in controlled conditions and in the wild at ca. 85 m depth in the Western Mediterranean Sea. Juveniles settled on seafloor macro-litter, with either arborescent or encrusting morphology, ranging from 0.6 to 3.5 mm in basal diameter and 0.2-7.1 years of age, also including a fraction (20%) of potentially sexually mature individuals. In controlled conditions, larvae settled and survived on plastic substrates for >60 days. Our insights show that marine plastic debris can provide favourable substrate for C. rubrum settlement either in controlled conditions or in the wild, suggesting their possible use in restoration activities. However, we pinpoint here that this potential benefit could result in adverse effects on population dynamics.

Microplastics reduce net population growth and fecal pellet sinking rates for the marine copepod, Acartia tonsa.

Microplastics (<5 mm) are ubiquitous in the global environment and are increasingly recognized as a biological hazard, particularly in the oceans. Zooplankton, at the base of the marine food web, have been known to consume microplastics. However, we know little about the impacts of microplastics across life history stages and on carbon settling. Here, we investigated the effects of ingestion of neutrally buoyant polystyrene beads (6.68 µm) by the copepod Acartia tonsa on (1) growth and survival across life history stages, (2) fecundity and egg quality, (3) and fecal characteristics. We found that microplastic exposure reduced body length and survival for nauplii and resulted in smaller eggs when copepods were exposed during oogenesis. Combining these life history impacts, our models estimate a 15% decrease in population growth leading to a projected 30-fold decrease in abundance over 1 year or 20 generations with microplastic exposure. In addition, microplastic-contaminated fecal pellets were 2.29-fold smaller and sinking rates were calculated to be 1.76-fold slower, resulting in an estimated 4.03-fold reduction in fecal volume settling to the benthos per day. Taken together, declines in population sizes and fecal sinking rates suggest that microplastic consumption by zooplankton could have cascading ecosystem impacts via reduced trophic energy transfer and slower carbon settling.

Assessment of plastic ingestion by pole-caught pelagic predatory fish from O'ahu, Hawai'i.

Although the frequency of occurrence of plastic ingestion in the large-sized dolphinfish and tunas taken by the Hawai'i longline fishery is very low (frequency of occurrence < 5% of sampled individuals), the ingestion of plastic in smaller-sized specimens caught with pole-and-line gear by commercial and recreational fishers has not been investigated.This study examined ingestion of >0.25 mm marine plastic debris (MPD) by four predatory fish species caught by commercial fishers around the Main Hawaiian Islands, and documented ingestion in three species: 85.7% of albacore tuna (n = 7), 40.0% of skipjack tuna (n = 10) and 12.5% of dolphinfish (n = 8).Yellowfin tuna (n = 10) did not contain any MPD, probably owing to the high proportion of empty stomachs (60%).For skipjack tuna, the frequency of occurrence of MPD ingestion was significantly higher for the smaller-sized specimens caught with pole-and-line (40%), compared with the larger-sized specimens caught with longlines (0%).For dolphinfish, the frequency of occurrence of MPD ingestion was similar for the similar-sized specimens caught with pole-and-line and with longlines.The ingested MPD items were micro-meso plastics, between 1 and 25 mm. While most ingested items were fragments, albacore also ingested line and skipjack also ingested sheets.The predatory fishes ingested light MPD items that float in sea water, but there were species-specific differences in their polymer composition: albacore contained more polypropylene and polyethylene, and skipjack contained more elastomers, characterized by a high percentage of ester plasticizers.Altogether, these results suggest that albacore and skipjack tunas ingest plastic of different types and polymers. Yet more research is needed to understand how differences in vertical distribution, foraging ecology and diet influence the MPD sampled by these predatory fish species.