Effects of metals in sediment under acidification and temperature rise scenarios on reproduction of the copepod Nitokra sp.

The potential effects of trace metal pollution in sediment under scenarios of warming and CO-driven acidification on the fecundity of the copepod Nitokra sp. were assessed. Ovigerous females were exposed to laboratory-spiked sediments at two different concentrations of a mixture of metals (Cu, Pb, Zn, and Hg) and to the control (non-spiked sediments), in combinations of two pH (7.

Biotic homogenization in multisystem cascade reservoirs: insights from sedimentary photopigment analysis.

The existing literature provides limited insights into the dynamics of phytoplankton communities and the spatial heterogeneity of physicochemical parameters in multisystem cascade reservoirs (interconnected reservoirs derived from different rivers). The existing studies are concentrated on cascade reservoirs (interconnected reservoirs derived from the same river). To address this knowledge gap, the aims of the present study were as follows: (1) investigate the spatial heterogeneity, within and between reservoirs, of geochemical parameters associated with the eutrophication process, considering total phosphorus, chlorophyll-a, pheophytin, and metals (chromium, copper, nickel, lead, zinc, iron, and manganese); (2) evaluate sediment quality at the designated locations; (3) assess differences in the richness and concentration of sedimentary photopigments between the reservoirs.

Five years after the collapse of the Fundão Dam: lessons from temporal monitoring of chemistry and acute toxicity.

In November 2015, the Fundão Dam break released millions of tons of metal-rich tailings into the Doce River Basin (DRB), causing catastrophic damage and potential ecological effects that reached the Atlantic Ocean. This study aimed to evaluate the geochemistry and toxicity of water and sediments collected in the DRB from 2015 to 2019 and to determine the spatial and temporal trends. Water and sediment samples were analyzed for metals and As by inductively coupled plasma optical emission spectrometry (ICP-OES), and acute toxicity for Daphnia similis or D.

Ocean warming and CO-driven acidification can alter the toxicity of metal-contaminated sediments to the meiofauna community.

Interactive effects of trace metal contamination, ocean warming, and CO-driven acidification on the structure of a meiofaunal benthic community was assessed. Meiofauna microcosm bioassays were carried out in controlled conditions in a full factorial experimental design which included three fixed factors: metal contamination in the sediment (3 levels of a mixture of Cu, Pb, Zn, and Hg), temperature (26 and 28 °C) and pH (7.6 and 8.

Bioaccumulation of heavy metals in estuaries in the southwest Atlantic Ocean.

The southwestern Atlantic Ocean is home to highly productive regions, composed of a mosaic of both protected and anthropogenically impacted areas, including the estuaries of Paranaguá, Cananéia, and Santos. In this study, concentrations of metals were measured in sediments and in marine organisms, collected from these three Brazilian estuaries. The higher concentrations of metals in the sediments from the Santos estuary are due to having the greatest intensity of anthropogenic activities.

Genotoxic effects of silver nanoparticles on a tropical marine amphipod via feeding exposure.

Silver nanoparticles (AgNP) are widely used in several applications including as antifouling agents; therefore, they can end up in estuarine and marine environments. These nanoparticles tend to aggregate and to deposit in the sediment, where many organisms feed and reproduce. Parhyale hawaiensis is an epibenthic amphipod globally distributed in tropical zones, and has been considered a potential model for ecotoxicology.

Assessment of crabs from Trindade, a Brazilian remote island: Support to marine studies.

Trindade is a remote island far from 1170 km of the Brazilian coast in the Atlantic Ocean, between South America and South Africa. The island has great biodiversity and scientific studies on the fauna and flora of Trindade are still scarce. Accordingly, since crustacean species of the island are also little known, this research features an unprecedented data set, which provides information on the level of potential toxic elements in two crab species: the Grapsus grapsus (herbivore) and the endemic species Gecarcinus lagostoma (omnivorous) which is in threatened status.

Mercury in trophic webs of estuaries in the southwest Atlantic Ocean.

Anthropogenic activities have impacted the coastal region of Brazil. In the Paranaguá estuarine complex (PEC), Cananéia-Iguape estuarine-lagoon complex (CIELC), and Santos-São Vicente estuarine complex (SSVEC), such activities occur across differing scales. In these estuaries, the concentrations of mercury (Hg) and stable nitrogen isotopes (δN) were investigated in sediments and marine organisms including benthic macrofauna, fish and cetaceans.

Assessment of metal contamination in fish from estuaries of southern and southeastern Brazil.

Historically, the Brazilian coast has been impacted by urban, industrial, and port activities that have increased the input of chemical contaminants, such as heavy metals, to the ecosystem. The Paranaguá estuarine complex (PEC), Cananéia-Iguape estuarine-lagoon complex (CIELC), and Santos-São Vicente estuarine complex (SSVEC) (S-SE Brazil) are surrounded by urbanized cities and port areas characterized by various anthropogenic discharges comprising several potential pollutants, including heavy metals. Concerns about such contamination are paramount because these estuaries are important for traditional fishing communities and are categorized as World Heritage sites and biodiversity hotspots by UNESCO.

Heavy metal concentrations in the benthic trophic web of Martel Inlet, Admiralty Bay (King George Island, Antarctica).

Knowledge of the metals behaviour in the Antarctic environment is important for conserving this continent, which can be impacted by local activities, such as research stations and by atmospheric and oceanic transport over long distances. As, Cd Cr, Cu, Hg, Ni, Pb and Zn levels and the nitrogen isotope ratio were investigated using benthic samples from Martel Inlet, Admiralty Bay. The results showed the biodilution of As and a tendency of increasing concentrations of Cd and Cu along the trophic web.

Bioaccumulation of heavy metals in marine organisms and sediments from Admiralty Bay, King George Island, Antarctica.

The Antarctic continent is considered a low-impact environment; however, there is a tendency to increase the contaminants' levels due to human activities in the research stations. In this study, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn levels in sediment and biota were determined in the environmental samples from Admiralty Bay (King George Island, Antarctica) collected in 2003. The results demonstrated high concentrations of Cu and Zn in the sediments.