Hepatic gene expression and liver histology were examined in sand flathead (Platycephalus bassensis) from six locations in Port Phillip Bay, Victoria, Australia. Four sets of genes including thyroid-related genes (D1, D2, TTR, TRα and TRβ), metal metabolism-related genes (MT, MTF1, TF, Ferritin and FPN1), apoptosis-related genes (Diablo/SMAC1, Diablo/SMAC2 and CYP1A) and an endoplasmic reticulum stress biomarker gene (GRP78) were examined in female flathead using qRT-PCR. TRβ and Diablo/SMAC1 gene expression was significantly up-regulated in fish from all polluted sites compared to those from a reference site. The transcripts of TRα and FPN1 were significantly higher in flathead from Corio Bay, while the hepatic mRNA of TTR and GRP78 were significantly lower in those fish. Positive correlations were observed between Diablo/SMAC1 and CYP1A, D2 and TRβ, TRα and TRβ. This study demonstrates that application of pathway-based biomarker genes and histopathology can provide comprehensive information on the impact of environmental pollutants on fish.

Our study aimed to evaluate crack cocaine effects in different life stages of the marine mussel Perna perna. For this purpose, fertilization rate, embryo-larval development, lysosomal membrane stability and DNA strand breaks were assessed. Effect concentrations in gametes and in larval development were found after 1h (IC50=23.53mg·L−1) and 48h (IC50=16.31mg·L−1), respectively. The highest tested concentration showing no acute toxicity (NOEC) was 10mg·L−1, while the lowest observed effect concentration (LOEC) was 20mg·L−1. NOEC concerning embryo-larval development was 0.625mg·L−1, while the LOEC was 1.25mg·L−1. Cyto-genotoxic effects were evidenced in mussels exposed to crack cocaine concentrations ranging from 5 to 500μg·L−1. Our results report the first data on effects of an illicit drug to marine organisms and should encourage further ecotoxicological studies of these contaminants of emerging concern in coastal ecosystems.

Between 2006 and 2013, we salvaged and necropsied 362 seabird specimens from Tern Island, French Frigate Shoals, Northwestern Hawaiian Islands. Plastic ingestion occurred in 11 of the 16 species sampled (68.75%), representing four orders, seven families, and five foraging guilds: four plunge-divers, two albatrosses, two nocturnal-foraging petrels, two tuna-birds, and one frigatebird. Moreover, we documented the first instance of ingestion in a previously unstudied species: the Brown Booby. Plastic prevalence (percent occurrence) ranged from 0% to 100%, with no significant differences across foraging guilds. However, occurrence was significantly higher in chicks versus adult conspecifics in the Black-footed Albatross, one of the three species where multiple age classes were sampled. While seabirds ingested a variety of plastic (foam, line, sheets), fragments were the most common and numerous type. In albatrosses and storm-petrels, the plastic occurrence in the two stomach chambers (the proventriculus and the ventriculus) was not significantly different.

In the present work we compared the type and frequency of gonadal abnormalities among Mytilus trossulus populations from the Gulf of Gdańsk, Baltic Sea. Observed histopathologies were grouped as regressive changes (RC, gonadal atresia (GA) and regression (GR)), progressive changes (PC, gonadal tumors) and intersex. Sex-based and spatial differences in frequency of RC were found, with the highest frequency of RC and PC found in mussels from polluted station B followed by mussels from station A located near a purification plant outlet. Bivalves from the reference area had the lowest frequency of RC.In order to confirm biomarker applicability of RC, an exposure experiment with model xenoestrogen 17α-ethinylestradiol (EE2) was performed. The exposure of M. trossulus to 50 and 500ngdL−1 of EE2 resulted in an increased frequency of gonadal regression and atresia, including melanized hemocytes infiltration in seminiferous tubules. We thus suggest that these changes can serve as biomarkers of endocrine disrupting compounds in biomonitoring studies.

The brain requires constant oxygen supply to perform its biological functions essential for survival. Because of low oxygen capacity and poor oxygen diffusibility of water, many fish species have evolved various adaptive mechanisms to cope with depleted oxygen. Endothelial cells (EC) are the primary components responsible for controlled environment of brain. Brain homeostasis largely depends on integrity of the EC. To elucidate their adaptive strategy, EC were isolated from the fish brain of Kovalam-control site and Ennore estuary-test/field hypoxic site and were subjected to low oxygen tension in laboratory. Cell viability, 4-hydroxynonenal (4HNE) and total antioxidant capacity (TAC) were analyzed to ascertain stress. Hypoxic insult, cytoprotective role of HSPs and apoptotic effect were analyzed by assessing hypoxia-inducible-factor-α (HIF1α), heat-shock-protein-70 (HSP70), heme-oxygenase 1 (HO-1), and apoptosis signal regulating kinase-1 (ASK1). This study evidenced that HSP70 and HO-1 are the key stress proteins, confer high tolerance to decreased oxygen tension mediated stress.

The presence of marine debris has been reported recently in several oceans basins; there is very little information available for Mexican Pacific coasts, however. This research examined the composition, possible sources, distribution, and density of Floating Marine Debris (FMD) during nine research surveys conducted during 2010–2012 in the Mexican Central Pacific (MCP). Of 1820 floating objects recorded, 80% were plastic items. Sources of FMD were determined using key objects, which indicated that the most were related to the presence of the industrial harbor and of a growing fishing industry in the study area. Densities were relatively high, ranging from 40 to 2440objects/km2; the highest densities were recorded in autumn. FMD were distributed near coastal regions, mainly in Jalisco, influenced by river outflow and surface currents. Our results seem to follow worldwide trends and highlight the need for further studies on potential ecological impacts within coastal waters of the MCP.

The effects of microplastic concentrations (10itemsl−1 and 1000itemsl−1) on the physiological responses of Atactodea striata (clearance rate, absorption efficiency, respiration rate) were investigated. The fates of ingested microplastics and the efficiency of depuration in removing ingested microplastics were also studied. A. striata ingested microplastics and the clearance rate was reduced at high concentration of microplastics. Since the respiration rate and absorption efficiency remained unchanged in exposed A. striata, reduction in the clearance rate would reduce the energy intake. Ingestion and retention of microplastics in the body were further limited by the production of pseudofaeces and faeces, and depuration in clean water, resulting in a very small amount of microplastics stored in the body of the clam.

A study was conducted to estimate how much of the annual load of dissolved inorganic nitrogen (DIN) from Great Barrier Reef (GBR) river basins could come from rainfall. Results suggest rainfall contributed ~37% of the average annual DIN load from the Fitzroy Basin over three wet seasons. Rainfall DIN contribution at plot to sub-catchment scale ranged from 5 to >100% for study sites in the Fitzroy and Pioneer Basins. An estimate using measured and modelled data indicates ~28% of the longer-term average annual DIN load from the entire GBR catchment may originate from rainfall. These estimates may affect current GBR management and water quality targets. Numerous studies predict increases in atmospheric nitrogen pollution from Asia via fossil fuel combustion and more frequent severe La Nina events via global warming. Future GBR rainfall chemistry data may be required for assessing catchment management outcomes and regional trends in atmospheric DIN deposition.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE | Dans cette étude, nous avons comparé l'évolution de trois grandes villes,

This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.