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Microplastics (MPs) are ubiquitous in marine compartments, and their transboundary distribution favours the dispersion and accumulation of particles in ecosystems. This study investigated MP contamination in four coastal fish species (Haemulon squamipinna , Chaetodon ocellatus , Syacium micrurum , and Alphestes afer) from the southwestern Tropical Atlantic. An alkaline treatment was applied to extract MPs from the digestive tracts, and a Laser Direct Infrared (LDIR) system was used to identify polymers. All species analysed were contaminated with MPs, with Alphestes afer being the most contaminated (1.45 ± 1.09 MPs individual−1; frequency of occurrence 80 %). No significant differences were found in the number and size of detected particles among species. The most common shapes were fibres and films, and polyethylene was the most abundant polymer. This study provides important baseline data on MP contamination in coastal fish species inhabiting complex habitat areas relevant for conserving marine biodiversity. [Display omitted] • 70 % of coastal fishes analysed were contaminated with microplastics. • Fibres and films were the most frequent microplastic shapes observed. • Microplastics found were smaller than 1 mm. • The most frequent polymers recorded were PE, PA, and PP. • Polymers identified suggest sources associated with fishing activities and tourism in the region. [ABSTRACT FROM AUTHOR]

Plastic pollution is present in most marine environments; however, contamination in pelagic predators, including species of economic interest, is still poorly understood. This study aims to access the macro- and microplastic contamination in tuna and large pelagic species and verify whether a trophic transfer occurs from prey to tunas captured by two fleets in the Southwestern Tropical Atlantic (SWTA). We combined different methodological approaches to analyse the intake of macro- and microplastics. In addition to examining the plastics in the fish' stomachs, we investigated the contamination in the prey retrieved from the guts of predators. A low frequency of occurrence (3%) of macroplastic was detected in the tuna and large pelagic species; conversely, we observed a high frequency of microplastic in the tuna's stomachs (100%) and prey analysed (70%). We evinced the trophic transfer of microplastics by analysing the ingestion rate of particles in prey retrieved from the tuna stomachs. In the 34 analysed prey, we detected 355 microplastic particles. The most contaminated prey were cephalopods and fishes of the Bramidae family. The most frequent microplastic shapes in both prey and tuna stomachs were foams, pellets and fibres (<1 mm). A variety of polymers were identified; the most frequent were styrene-butadiene rubber (SBR), polyamide (PA), polyethylene terephthalate (PET) and polyethylene (PE). Our findings enhance scientific knowledge of how the ecological behaviour of marine species can affect microplastic intake. [Display omitted] • All the Thunnus albacares analysed were contaminated with microplastics. • The high contamination rate may be due to the opportunistic behaviour of species. • Foams and pellets smaller than 1 mm were the main shape of microplastics found. • A variety of polymers were identified, including the styrene-butadiene rubber. • We observe strong evidence of microplastic trophic transfer in tunas. [ABSTRACT FROM AUTHOR]

For centuries, intertidal fishing in mangroves using block nets has been of socio-economic and cultural importance to many tropical fishing communities. However, data characterising these fisheries are scarce, and no study on their selectivity has been conducted. Additionally, assessing the impact of block net fisheries is complex because they target migrant fish species with different life cycles and morphologies in highly dynamic environments. Here, we investigated the catch composition and selectivity of intertidal fishing in northeastern Brazil to discuss how this should be considered for management purposes. We described the spatiotemporal variability of catch composition in four estuaries with distinct physicochemical parameters. We used three model species (Eucinostomus argenteus, Mugil curema, and Centropomus undecimalis) to understand how block net selectivity varied according to fish morphology (body height (BH)) and life cycle (size at first maturity and ontogenetic stages). We found an important spatiotemporal variability in catches that are likely linked to local (geomorphology, precipitation) and seasonal factors (species reproduction). Immature individuals dominated the catch of the three species of interest, confirming that mangroves are a nursery for many migratory species. Moreover, for the first time, we described the S-shaped curve selectivity pattern of block nets, which is unusual for passive nets and prevents the escape of larger individuals, making this gear very efficient to capture a wide range of sizes. We found that comparing length at first catch (L c) and size at first maturity constituted a simple way to consider fisheries' interference with the species life cycle. In addition, the body height at L c was similar between species, making the ratio BH/TL a possible proxy of L c in a data-poor context. The main concern about block net fisheries is the growth overfishing of long-lived species targeted at the coast. Since mangrove and coastal fisheries explore the same species at different ontogenetic stages, an ecosystem approach to fisheries should be applied to the entire coastal continuum. This approach should involve effort regulation to control the overall fishing pressure, but not mesh size limits that would considerably be detrimental to block net fisheries yield. [ABSTRACT FROM AUTHOR]