Baseline polycyclic aromatic hydrocarbon maternal transfer data in Lesser Numbfish Narcine brasiliensis (Elasmobranchii: Batoidea) from an impacted estuary in Southeastern Brazil.

Maternal offloading of polycyclic aromatic hydrocarbons (PAHs) poses a significant exposure route for developing embryos, with implications for subsequent generations. Despite known developmental effects regarding fish physiology and behavior, maternal PAH transfer assessments in elasmobranchii are still lacking. This study investigated PAH contamination and maternal transfer in one female Lesser Numbfish (Narcine brasiliensis) electric ray and seven embryos for the first time. Naphthalene was identified as the predominant low molecular weight PAH, and dibenzo[a,h]anthracene was the most abundant high molecular weight compound. Most embryos exhibited some level of PAH exposure, with varying accumulation patterns potentially influenced by size, developmental stage, and yolk absorption rates. Further investigation is warranted to understand the impacts of PAH maternal offloading on elasmobranchii uterine contents and embryos.

A systematic review on polycyclic aromatic hydrocarbon contamination in elasmobranchs and associated human health risks.

Polycyclic aromatic hydrocarbon (PAH) contamination is ubiquitous and comprises a significant worldwide concern in ecological and Public Health frameworks. Many aquatic biota representatives have been reported as contaminated by these toxic compounds, including one of the most threatened vertebrate groups, elasmobranchs (sharks and rays). Although elasmobranchs play important ecological roles and provide significant ecosystem services, they are highly consumed and comprise a cheap source of protein for humans globally. Studies concerning elasmobranch PAH contamination are, however, notably lacking. A systematic review was, thus, conducted herein to assess PAH elasmobranch contamination and discuss potential human health risks following the Preferred Reporting Item Statement Guidelines for Systematic Reviews and Meta-analyses (PRISMA) guidelines applying the Population (P), Intervention (I), Comparison I, and Outcome (O) (PICO) strategy. A total of 86 published papers were retrieved by this method and analyzed. Only nine studies of this total concerned PAH elasmobranch contamination, assessed in 10 shark species and one ray species, with only one study calculating human health risks. A significant knowledge gap is, thus, noted for this subject, indicating the need to monitor PAH elasmobranch contamination in consumed shark and ray species worldwide.

Environmental quality assessment in a marine coastal area impacted by mining tailing using a geochemical multi-index and physical approach.

Mining has been described as an important source of contaminants to the coastal zone worldwide, which is greatly intensified in the case of tailing dam ruptures. This study assessed the environmental quality of the marine coastal area impacted by a mining disaster (Fundão Mine dam collapse on 05 November 2015, Southeast Brazil) by applying a geochemical multi-index and physical approach over 18 months (from October 2018 to March 2020). Nutrients, metal(oid)s and Polycyclic Aromatic Hydrocarbons (PAHs) were integrated by quality indexes: Canadian Council of Ministers of the Environment Water Quality Index (CWQI) and the Pollution Load Index (PLI) for water quality; Sediment Quality Guideline Quotients (SQG-q metal(oid)s and SQG-q PAHs) for sediment quality. Three scenarios regarding river discharge and wave-heights (Hs) were considered: 2018/2019-wet, 2019-dry, 2019/2020-wet. An Environmental Risk Assessment framework was built to describe the overall environmental quality in regards to water and sediment quality indexes as well as physical conditions. Here we show that the worsening of environmental quality is highly associated with the decrease of water quality by metal(oid)s (total forms of As and Ni; dissolved forms of Co and Fe) during the 2019-dry scenario when river discharge was at the lowest and the highest Hs occurred. Resuspension of fine sediment and suspended Fe(III) oxy-hydroxide nanoparticles by waves seem to be the main processes for releasing metal(oid)s into the water column. CWQI and PLI showed marginal and polluted conditions for water quality, respectively, and SQG-q for metals and PAHs indicated moderate impact in the sediment during the 2019-dry period. Toxicity to pelagic and benthic fauna is expected to occur in those conditions. Recovery of environmental quality occurred during the 2019/2020-wet scenario, which could be explained by alongshore and offshore transport of sediment and the dilution of aqueous metal(oid)s by intense river discharge on the continental shelf.