Metabolic Regulation of Copper Toxicity during Marine Mussel Embryogenesis.

The development of new tools for assessing the health of cultured shellfish larvae is crucial for aquaculture industries to develop and refine hatchery methodologies. We established a large-volume ecotoxicology/health stressor trial, exposing mussel () embryos to copper in the presence of ethylenediaminetetraacetic acid (EDTA). GC/MS-based metabolomics was applied to identify potential biomarkers for monitoring embryonic/larval health and to characterise mechanisms of metal toxicity.

A review on per- and polyfluorinated alkyl substances (PFASs) in microplastic and food-contact materials.

Plastic, paper and cardboard are widely used as food contact materials (FCMs), due to its numerous favourable characteristics. However, they are usually coated with hazardous substances, such as per- and polyfluorinated alkyl substances (PFASs). PFASs, with its functional properties of oil- and water-repellency, can migrate from FCMs into the food and cause potential risk to human health.

Survey of legacy and emerging per- and polyfluorinated alkyl substances in Mediterranean seafood from a North African ecosystem.

Despite the ubiquity of per- and polyfluorinated alkyl substances (PFAS) in all environmental compartments, little is known about the pollution they cause on the African continent, neither on levels, nor effects. Here we examined the occurrence and levels of 21 legacy and emerging PFAS in 9 marine species (3 fish, 2 crustaceans and 4 mollusks) collected from Bizerte lagoon, Northern Tunisia. Furthermore, assessment of potential human health risks through consumption of contaminated seafood was examined.

Parameters Governing the Community Structure and Element Turnover in Kermadec Volcanic Ash and Hydrothermal Fluids as Monitored by Inorganic Electron Donor Consumption, Autotrophic CO Fixation and 16S Tags of the Transcriptome in Incubation Experiments.

The microbial community composition and its functionality was assessed for hydrothermal fluids and volcanic ash sediments from Haungaroa and hydrothermal fluids from the Brothers volcano in the Kermadec island arc (New Zealand). The Haungaroa volcanic ash sediments were dominated by epsilonproteobacterial sp. Ratios of electron donor consumption to CO fixation from respective sediment incubations indicated that sulfide oxidation appeared to fuel autotrophic CO fixation, coinciding with thermodynamic estimates predicting sulfide oxidation as the major energy source in the environment.

Copper toxicity to blue mussel embryos (Mytilus galloprovincialis): The effect of natural dissolved organic matter on copper toxicity in estuarine waters.

Copper (Cu) is a naturally occurring micronutrient of eco-toxicological concern in aquatic ecosystems. Current knowledge of Cu-speciation and bioavailability in natural saline environments is insufficient to adequately inform environmental protection policy for estuarine systems. We assessed the combined effect of two of the main drivers of metal bioavailability, salinity and natural dissolved organic carbon (DOC), on Cu-speciation and associated Cu-toxicity to blue mussel (Mytilus galloprovincialis) embryos in a standard 48-h bioassay.

Copper pollution exacerbates the effects of ocean acidification and warming on kelp microscopic early life stages.

Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae and their microscopic life stages.

Iron stable isotopes track pelagic iron cycling during a subtropical phytoplankton bloom.

The supply and bioavailability of dissolved iron sets the magnitude of surface productivity for ∼ 40% of the global ocean. The redox state, organic complexation, and phase (dissolved versus particulate) of iron are key determinants of iron bioavailability in the marine realm, although the mechanisms facilitating exchange between iron species (inorganic and organic) and phases are poorly constrained. Here we use the isotope fingerprint of dissolved and particulate iron to reveal distinct isotopic signatures for biological uptake of iron during a GEOTRACES process study focused on a temperate spring phytoplankton bloom in subtropical waters.

Fate of copper complexes in hydrothermally altered deep-sea sediments from the Central Indian Ocean Basin.

The current study aims to understand the speciation and fate of Cu complexes in hydrothermally altered sediments from the Central Indian Ocean Basin and assess the probable impacts of deep-sea mining on speciation of Cu complexes and assess the Cu flux from this sediment to the water column in this area. This study suggests that most of the Cu was strongly associated with different binding sites in Fe-oxide phases of the hydrothermally altered sediments with stabilities higher than that of Cu-EDTA complexes. The speciation of Cu indicates that hydrothermally influenced deep-sea sediments from Central Indian Ocean Basin may not significantly contribute to the global Cu flux.

Numerical approach to speciation and estimation of parameters used in modeling trace metal bioavailability.

Speciation affects trace metal bioavailability. One model used to describe the importance of speciation is the biotic ligand model (BLM), wherein the competition of inorganic and organic ligands with a biotic ligand for free-ion trace metal determines the ultimate metal availability to biota. This and similar models require natural ligand concentrations and conditional stability constants as input parameters.

Acquisition of iron by alkaliphilic bacillus species.

The biochemical and molecular mechanisms used by alkaliphilic bacteria to acquire iron are unknown. We demonstrate that alkaliphilic (pH > 9) Bacillus species are sensitive to artificial iron (Fe³+) chelators and produce iron-chelating molecules. These alkaliphilic siderophores contain catechol and hydroxamate moieties, and their synthesis is stimulated by manganese(II) salts and suppressed by FeCl₃ addition.