Microplastic contamination in different shell length in Tivela mactroides (Born, 1778).

Microplastic identification and distribution throughout oceans has become a great concern due to its substantial uprising and its consequent interactions with marine biota. Microplastics can be absorbed and adsorbed by several marine species owing to their very small size. Among these organisms are bivalves, including ones used as food for humans. In this context, this research aims to understand the absorption scale of microplastics by Tivela mactroides according to their size and consequently life stage. Thus, T. mactroides mussels were collected at Camburi Beach (Brazil) and grouped into 30 different size classes from 06 to 35 mm. Later, 20 specimens from each size class (N = 600) had the soft tissues removed and a pool was performed through digestion with 10 % KOH solution. Results showed the presence of microplastics in all size classes of T. mactroides, evidencing that organisms from 06 mm can already be contaminated by microplastics and a tendency of the number of microplastics particles to increase as shell size increases. Furthermore, the amount of blue filament-type MPs was significantly higher than the other types and colors. Additionally, analyzes performed by Raman spectroscopy showed that the blue filaments have a PET composition. Finally, larger individuals presented larger quantities of MPs, as well as larger filaments. This might suggest that there are differences between the assimilation of the size of MPs in the different size classes, i.e. that size makes a difference.

Abundance of microplastic in different coastal areas using Phragmatopoma caudata (Kroyer in Morch, 1863) (Polychaeta: Sabelariidae) as an indicator.

Plastic debris has been reported in the marine environment since the '70s. These plastic materials are introduced into the marine environment in several sizes, one of them microplastics (MP), and they have drawn great interest and concern in the past decades. Consumption of MP can cause weight loss, feeding rate decrease, reproductive activity decrease, and several other negative effects. Ingestion of MPs has already been reported for some species of polychaetes but the use of these annelids in MP studies is still poorly reported. Costa et al. (2021) was the first study to investigate the capability of the reef-building polychaete Phragmatopoma caudata to incorporate microplastic in its colony's structures. This makes the colonies a reservoir of MP and thus they reflect the environment's quality regarding MP presence. Consequently, this specie becomes an important asset to MP pollution investigation in coastal areas. Therefore, this work aims to investigate the abundance of MPs on the coastline of Espírito Santo using P. caudata as an indicator of MP presence. For this, we collected samples of P. caudata colonies in 12 sampling sites along the Espírito Santo coast (three replicates at each site). These colony samples were processed to extract the MPs particles from the colony surface, its inner structure, and tissues from the individuals. These MPs were counted using a stereomicroscope and sorted according to their color and type (filament, fragment, and other). Statistical analysis was performed using GraphPad Prism 9.3.0. Significant values followed p < 0.05. We found MP particles in all 12 sampled beaches, configuring a pollution rate of 100 %. The number of filaments was notably greater than the number of fragments and others. The most impacted beaches were found inside the metropolitan region of the state. Finally, P. caudata is an efficient and trustable indicator of microplastic in coastal areas.

Abundance, composition, and distribution of microplastics in intertidal sediment and soft tissues of four species of Bivalvia from Southeast Brazilian urban beaches.

In coastal areas, microplastics (MPs) can deposit in sediment, allowing it to be ingested by benthic organisms, like mussels, thus creating a possible transfer to humans. The aim of this study is to evaluate MPs pollution in sediment as a function of shoreline elevation in two urbanized beaches and to evaluate the abundance/frequency of MPs in 4 different species of bivalves commonly used in the human diet, such as the oyster Crassostrea brasiliana, the mussels Mytella strigata and Perna perna and the clam Tivela mactroides, and identify the polymers via µ-FTIR technique. A total of 3337 MPs were found in this study, of which 1488 were found in the sediment at the five sites analyzed, and 1849 in the bivalve tissues at the two sampling sites. MPs contamination was observed in all sediment samples and species of the pool and in each of the 10 specimens of the four species. Thus, the frequency of contamination by MPs reached 100 % for the analyzed samples. The number of filaments is higher than fragments in sediment samples and in each bivalve species. Regarding types and colors, the blue were greater than fragment-type in sediments and samples. In an effort to classify the polymers via µ-FTIR, our study was able to identify polypropylene, polyethylene and polyethylene terephthalate, besides a great number of cellulose fibers.

Spatial distribution of microplastics in the superficial sediment of a mangrove in Southeast Brazil: A comparison between fringe and basin.

The presence of microplastics (MPs) has been observed globally in every marine environment, including mangroves. However, the distribution of MPs in mangroves comparing fringe and basin forests and their ecological consequences need be better investigated. The objectives of this study were to verify the presence, distribution and types of MPs in a mangrove area in southeast Brazil. Further, we linked the presence of vegetation and urban activities with MPs presence at these sites. Eight mangrove sites in Vitória Bay were delimited and classified as fringe or basin, totaling 16 sample points. Superficial sediments were collected, then MPs classified and quantified by shapes and colors. A total of 2175 MPs were observed in the mangrove basin and fringe of sites analyzed (66.4% and 33.6%, respectively), suggesting high levels of MPs in basin sites. The color proportion of MPs found was blue (54%), transparent (21%), black (10%), red and green (6% each) and yellow and white (<1% each). Filaments accounted for 88.7% of the total, compared with 11.3% from fragments. The majority of MPs were found at the basin sites with less preserved vegetation. A positive correlation was found between the total number of MPs and the density of dead vegetation, indicating that degraded environments are more susceptible to MP accumulation. Thus, our data suggest that MPs are widely distributed and associated with lower hydrodynamism (basin region), less preserved vegetation and urban activities.

Quantitative evaluation of microplastics in colonies of Phragmatopoma caudata Krøyer in Mörch, 1863 (Polychaeta-Sabellariidae): Analysis in sandcastles and tissues and identification via Raman spectroscopy.

The detection of microplastics in all world oceans, including the most remote, has become a major concern as this will substantially increase the possibility of interactions between these particles and the marine biota. Due to their small size, microplastics can be ingested by many marine species including invertebrates, causing physical damage. This study was the first evaluation of the occurrence and abundance of microplastics in three sample types related to the species Phragmatopoma caudata, (i.e. colony wash water, tubes and digested tissue from specimens). In total, 2118 samples of microplastics were quantified, with 1516 obtained from the wash water, 447 from the fragmented tubes and 155 from the digested tissue. Three types of microplastics were chemically identified via Raman Spectroscopy as polyethylene, polypropylene and polyethylene terephthalates. Overall, this study demonstrated that microplastics are abundantly bioavailable in the studied area and are present as filament and fragment shapes.

A temporal and spatial monitoring of organotin pollution in a harborside region of Brazil by imposex and ecological quality ratio using Leucozonia nassa.

This study represents the first use of Leucozonia nassa (Mollusca-Gastropoda) in a program of long-term monitoring. Specimens of L. nassa were collected between 2006 and 2014 and analyzed for the occurrence of imposex in two areas in Southeastern Brazil, one control area and another characterized by the presence of many ports and marinas. Imposex was evaluated in nine sites based on the percentage of females exhibiting imposex (I%), relative penis length index and vas deferens sequence index, classical indices to evaluate tributyltin (TBT) impacts. Moreover, this study uses for the first time in a tropical environment the ecological quality ratio (EQR), an approach to verify the imposex levels as an indicator of the impact by organotin compounds according to the EU Water Framework Directive. The results confirm the occurrence of high levels of imposex in L. nassa with all the indices evaluated. Furthermore, the results also indicate that, despite the international ban, antifouling paints based on TBT are still possibly used in Brazil. In addition, this study shows that L. nassa has the characteristics that make it a suitable bioindicator to monitor TBT pollution, and that the use of the EQR may create important data regarding this problem.

Organotins: a review of their reproductive toxicity, biochemistry, and environmental fate.

The review purposes are to (1) evaluate the experimental evidence for adverse effects on reproduction and metabolism and (2) identify the current knowledge of analytical procedures, biochemistry and environmental aspects relating to organotins. Organotins are pollutants that are used as biocides in antifouling paints. They produce endocrine-disrupting effects in mollusks, such as imposex. In rodents, organotin exposure induces developmental and reproductive toxicity as well as alteration of metabolic homeostasis through its action as an obesogen. The adverse effects that appear in rodents have raised concerns about organotins' potential health risk to humans in relation to organotin exposure. At present, triorganotin, such as tributyltin, have been demonstrated to produce imposex, and mammalian reproductive and metabolic toxicity. For most mammals, triorganotin exposure predominantly occurs through the ingestion, and this compound can cross the placenta. With these risks in mind, it is important to improve our knowledge of organotins' effects on environmental health.