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Deception Island is amongst the most active volcanoes in the Southern Ocean, with over 20 explosive eruptions in the last ca. 200 years. The eruption that formed the caldera at Deception Island occurred 3980 ± 125 calendar years Before Present, and it is the largest eruptive event documented in Antarctica during Holocene. Since then, post-caldera volcanic activity has comprised many scattered eruptive vents across the island. Mortality of benthic organisms has been reported during the most recent eruptions occurred on the island, in 1967, 1969, and 1970 Common Era (CE), with very low abundances of organisms during the 1967–1973 CE period. Within the sea-flooded part of the caldera depression, named Port Foster, a submarine volcanic axis with several volcanic cones is observed. An interdisciplinary team sampled the best morphologically preserved volcanic edifice within Port Foster, the so-called Stanley Patch. Geophysical data traced the volcano and characterized its morphology and inner structure. Underwater scuba sampling allowed to acquire sediment and rock samples, photographs and video images of the benthic organisms and seascape. Morphology of Stanley Patch cone and textural characteristics of the collected pyroclastic rocks indicate that the volcanic edifice was originated during an explosive eruption. Furthermore, the lack of palagonitization, quenched pyroclast margins, and hyaloclastite deposits indicate that this cone has formed on-land, before the caldera floor became inundated by the seawater, highlighting the complex intra-caldera evolution of Deception Island. A sediment core from the crater was collected for sedimentological, and geochemical analysis. Antarctic climate and seasonal sea ice, together with organic degradation due to high sedimentation rates, explain the low total organic carbon data measured. The volcanic history of the island has probably avoided the development of a stable benthic community over time, similar to other Antarctic shallow communities. Moreover, the current geomorphological conditions still shape different benthic communities than in the surrounding coastal ecosystems. Stanley Patch, and the whole Port Foster, provide a natural laboratory for benchmarking the reestablishment of benthic communities on a volcanic-influenced shallow marine environment, offering relevant data for future studies evaluating global climate change effects on the Antarctic seabed., SCOPUS: ar.j, info:eu-repo/semantics/published

The current increase in atmospheric CO2 concentration induces changes in the seawater carbonate system resulting in decreased pH and calcium carbonate saturation state, a phenomenon called ocean acidification (OA). OA has long been considered as a major threat to echinoderms because their extensive endoskeleton is made of high-magnesium calcite, one of the most soluble forms of calcium carbonate. Numerous studies addressed this question in sea urchins, but very few questioned the impact of OA on the sea star skeleton, although members of this taxon do not compensate their extracellular pH, contrary to most sea urchins. In the present study, adults of the common sea star, Asterias rubens from Kiel Fjord, a site experiencing natural acidification events exceeding pCO2 levels of 2500 µatm, were chronically exposed to different levels of simulated ocean acidification (pHT-SW 8.0, 7.4, 7.2), encompassing present and future conditions, for the duration of 109 days. Corrosion and mechanical properties of skeletal elements were studied using scanning electron microscopy, three-point bending tests as well as nanoindentation. The spines were significantly corroded at pHT-SW 7.4 and below while the ambulacral plates were only affected at pHT-SW 7.2. Nanoindentation of newly formed spines and ambulacral plates did not reveal significant CO2-induced differences in skeleton hardness or elasticity across treatments. Results of three-point bending tests revealed significantly reduced characteristic strength and fracture force of ambulacral plates from the median arm segment at pHT-SW 7.4 and below. These plates are those supporting the tube feet involved in the opening of bivalves during feeding and in the animal attachment to the substrate. Under reduced seawater pH, this might result in fracture of sea star plates during predation on mussel. The present results predict a possible impact of ocean acidification on the skeletal integrity of a marine keystone predator., info:eu-repo/semantics/inPress

Background Most of the experience on fenestrated endovascular aneurysm repair involves the custom-made Zenith® endograft (Cook). The fenestrated Anaconda® endograft (Vascutek) was introduced with the potential advantages of complete repositioning and lack of stent material on the main aortic body for more versatility. However, few data are available. Our objective was to assess its mid-term results in the treatment of complex aortic aneurysms. Methods Consecutive patients treated with the custom-made fenestrated Anaconda endograft in France and the Principality of Monaco, from December 2010 to October 2015, were included. Results Eighty-six patients were included over 16 centers (82 men, mean age 73.4 ± 8.1 years, 16 (18.6%) symptomatic aneurysms). The repositioning system was used in 68 cases (79.1%). Two hundred ninety-two visceral/renal vessels were targeted, with a mean number of 3.4 ± 0.6 target vessels/patient and a successful reconstruction in 99.3% of the cases (290/292 vessels). Perioperative technical success was achieved in 86.0% (74/86 patients). In-hospital and 30-day mortality rates were 3.5% (3 patients) and 7.0% (6 patients), respectively. At 12 and 24 months, estimated overall survival rate was 88.3% and 85.2%, target vessel's patency rate was 97.2% and 96.3%, and freedom from aneurysm-related reintervention rate was 96.3% and 88.0%, respectively. At 24 months, there were 7 type II endoleaks (12.7%) and a significant reduction in aneurysm maximum transverse diameter in 70.4%. Five limb occlusions occurred at 1-year and 1 at 2-year follow-up (7.0%). Conclusions The fenestrated Anaconda stent-graft system offers acceptable technical success rates, mid-term efficacy, and durability with respect to aneurysm sac regression, target vessel patency, overall mortality, and reintervention rates. Long-term results are still awaited, until then, the rate of graft limb occlusion is of concern and should be further investigated, especially in case of particularly complex aortic anatomies.

Sea stars (Asterias rubens L.) were collected in different stations distributed in the Southern Bight of the North Sea. Concentrations of four heavy metals and six PCB congeners were measured in two body compartments (body wall and pyloric caeca). In order to assess the potential harm of these contaminants, two biochemical parameters were measured in sea stars, viz. reactive oxygen species (ROS) production by amoebocytes and cytochrome P450 immunopositive protein (CYP1A IPP) induction in pyloric caeca. Sea stars from stations located in the plume of the Scheldt river showed the highest contamination levels. Other stations, similarly located, displayed lower levels. No simple relationship could be established between ROS production by sea star amoebocytes and contaminant levels measured in sea star tissues. CYP1A IPP induction displayed more contrasted responses, and highly significant regressions were found between PCB concentrations measured in pyloric caeca and CYP1A IPP. Both biological parameters were found to vary significantly over the study area. On the whole, data indicated that contamination levels and subsequent effects in sea stars were comparable to those described in previous large-scale studies, but that working at a smaller scale highlighted the existence of patterns of contamination which can blur general trends due to major contamination sources like contaminated rivers.

Microbial community composition and structure were characterized in marine sediments contaminated for >80 years with cadmium, copper, lead, and zinc. Four sampling sites that encompass a wide range of sediment metal loads were compared in a Norwegian fjord (Sørfjord). HCl-extractable metals and organic matter constantly decreased from the most contaminated site (S1) to the control site (S4). All sampling sites presented low polychlorinated biphenyl (PCB) concentrations (Σ 7 PCB < 7.0 ng g [dry weight] −1 ). The biomass ranged from 4.3 × 10 8 to 13.4 × 10 8 cells g (dry weight) of sediments −1 and was not correlated to metal levels. Denaturing gradient gel electrophoresis indicated that diversity was not affected by the contamination. The majority of the partial 16S rRNA sequences obtained were classified in the γ- and δ- Proteobacteria and in the Cytophaga-Flexibacter-Bacteroides (CFB) bacteria. Some sequences were closely related to other sequences from polluted marine sediments. The abundances of seven phylogenetic groups were determined by using fluorescent in situ hybridization (FISH). FISH was impaired in S1 by high levels of autofluorescing particles. For S2 to S4, the results indicated that the HCl-extractable Cu, Pb, and Zn were negatively correlated with the abundance of γ- Proteobacteria and CFB bacteria. δ- Proteobacteria were not correlated with HCl-extractable metals. Bacteria of the Desulfosarcina-Desulfococcus group were detected in every site and represented 6 to 14% of the DAPI (4′,6′-diamidino-2-phenylindole) counts. Although factors other than metals may explain the distribution observed, the information presented here may be useful in predicting long-term effects of heavy-metal contamination in the marine environment.

The study assessed the occurrence, possible toxicity, and impact of sediment-associated metals and PCBs in the coastal zone of the southern North Sea using echinoderms as representatives of the macrobenthos. Metals and PCBs were analyzed in the sediments and in the body compartments of the starfish Asterias rubens from 11 stations. The general toxicity of sediment-associated contaminants was assessed by bioassays using embryonic and larval developments of both A. rubens and the sea urchin Psammechinus miliaris. The impact of contamination was assessed by measuring cellular immune responses of A. rubens collected in the same stations. Contamination of the starfish by metals and PCBs closely reflected that of the sediments. However, bioaccumulation was element-specific for metals and depended on the chlorination pattern for PCBs. The sediment-associated contaminants appeared to be toxic in both the A. rubens and P. miliaris developmental assays. Moreover, metals were shown to affect the immune responses of starfishes living in contaminated stations. The most significant effects on biological responses were recorded in the plumes of the Scheldt/Rhine/North Sea Canal and the Elbe/Weser Rivers.

A technique using rubidium chloride (RbCl), a trace element, as internal label is proposed for marking hymenopteran parasitoids attacking a concealed host, Ips typographus L. (Coleoptera: Scolytidae). RbCl was introduced directly into spruce via the vascular system using glass tubing. RbCl passed through the food chain and was detected at the parasitoid level by electrothermal atomic absorption spectroscopy (EAAS) or flame emission spectroscopy (FES). Mark persistency until day 8 after emergence was tested in labelled Rhopalicus tutela (Walker) (Hymenoptera: Pteromalidae). The mark decreased with time only in fed females, probably due to excretion and/or egg resorption. The proportion of marked males did not vary with time or treatment.

The common starfish, Asterias rubens, occurs in fluctuating environments in the North Atlantic. To better understand energy allocation dynamics, we recorded gonad, body wall, and pyloric caeca (storage organ) indices between 2000 and 2004 from three different habitats. We applied a Fourier transform to the data to evaluate and compare the seasonal variation in these indices. Specific effects of emersion and salinity variation were examined in two laboratory studies. Differences in energy allocation were found between sites and temporally within sites. Food availability appeared to be the most important factor controlling allocation dynamics while fluctuating salinity and/or emersion had a significant but smaller impact. Only severe food shortage reduced reproductive investment indicating a preferential energy allocation to gonads. This study is the first to encompass a broad range of populations over several reproduction cycles and emphasizes the ability of A. rubens to adapt to a fluctuating environment.

[1] Biogenic calcites may contain considerable magnesium concentrations, significantly higher than those observed in inorganic calcites. Control of ion concentrations in the calcifying space by transport systems and properties of the organic matrix of mineralization are probably involved in the incorporation of high magnesium quantities in biogenic calcites, but their relative effects have never been quantified. In vitro precipitation experiments performed at different Mg/Ca ratios in the solution and in the presence of soluble organic matrix macromolecules (SOM) extracted from sea urchin tests and spines showed that, at a constant temperature, magnesium incorporation in the precipitated minerals was mainly dependent on the Mg/Ca ratio of the solution. However, a significant increase in magnesium incorporation was observed in the presence of SOM compared with control experiments. Furthermore, this effect was more pronounced with SOM extracted from the test, which was richer in magnesium than the spines. According to SEM observations, amorphous calcium carbonate was precipitated at high Mg/Casolution. The observed predominant effect of Mg/Casolution, probably mediated in vivo by ion transport to and from the calcifying space, was suggested to induce and stabilize a transient magnesium-rich amorphous phase essential to the formation of high magnesium calcites. Aspartic acid rich proteins, shown to be more abundant in the test than in the spine matrix, further stabilize this amorphous phase. The involvement of the organic matrix in this process can explain the observation that sympatric organisms or even different skeletal elements of the same individual present different skeletal magnesium concentrations.

The present study evaluated the effects of field metal contamination on sperm motility and the RNA/DNA ratio in echinoderms. Populations of Asterias rubens and Echinus acutus that occur naturally along a contamination gradient of sediments by cadmium, copper, lead, and zinc in a Norwegian fjord (the Sørfjord) were studied. Sperm motility, a measure of sperm quality, was quantified using a computer-assisted sperm analysis system. The RNA/DNA ratio, a measure of protein synthesis, was assessed by a one-dye (ethidium bromide)/one-enzyme (RNase), 96-well microplate fluorometric assay. Although both species accumulate metals at high concentrations, neither sperm motility parameters in A. rubens nor the RNA/DNA ratio in both species were affected. The Sørfjord is still one of the most metal-contaminated marine sites in Europe, but even so, populations of A. rubens and E. acutus are able to endure under these conditions.

The eubacterial communities adherent to sediment particles were studied in heavy metal contaminated coastal sediments. Six sampling sites on the Belgian continental plate and presenting various metal loads, granulometries, and organic matter content, were compared. The results indicated that the total microbial biomass (attached + free-living bacteria) was negatively correlated to HCl-extractable metal levels (p

Concentrations of the essential trace metals copper and zinc were measured in the pyloric caeca of female Coscinasterias muricata sampled from Port Phillip Bay, Victoria, Australia at monthly intervals for 15 months. Results indicate that the concentrations of these metals appear to be regulated by the reproductive cycle. Peaks in zinc concentration occurred simultaneously with peaks in progesterone concentration in the pyloric caeca. These findings suggest that zinc plays a role in gametogenesis and ovarian development. Fluctuations in pyloric caeca copper concentration appear inversely related to the pyloric caecal index and associated with oocyte diameter, indicative of a role for this metal in oogenesis. The levels of cytosolic heat stable low molecular mass (LMM) proteins were examined throughout the sampling period. Heat stable LMM proteins (metallothionein-like) of 12 kDa and 7.5 kDa (apparent molecular mass) and the concentrations of copper appear to be related; although the exact nature of these proteins remains unknown. No such relationship was observed between the levels of heat stable LMM proteins and zinc.

In invertebrates, the phagocytosis exerted by immune cells constitutes the main line of internal defence against offending microorganisms. This study assessed during two consecutive years the phagocytic activity in seastars (Asterias rubens) collected in stations along the Belgian and Dutch coasts. The contamination of these seastars by metals and PCBs were measured in parallel. Increased phagocytic activities were found in seastars collected in the plume of the Scheldt river. This correlated with the contamination of seastars by metals, mainly Pb, but not with the contamination by the analysed PCB congeners. Furthermore, the relationship between phagocytosis and metal contamination was reproducible from one year to another. The possible mechanisms explaining this effect are discussed in light of a direct or indirect link between phagocytic activity and metal contamination of seastars.

Several parameters of cellular immunity in seastars fed Cd-contaminated mussels were analyzed. The accumulation of cadmium in the seastars did not alter the concentration of amoebocytes in the coelomic fluid. On the contrary, the immune cells showed a reduced phagocytic activity and an increased production of reactive oxygen species. These effects may lead to an inability of the seastars to cope with bacterial infections and to oxidative damages to self tissue that could threaten the survival of the animals.

To study the effects of metals on starfish in field conditions, immune responses were measured in starfish from natural populations along a metal pollution gradient (long-term contamination) and in starfish that were transferred up the gradient (short-term contamination). Coelomic amoebocyte concentration (CAC) and production of reactive oxygen species (ROS) by amoebocytes were measured in two varieties of Asterias rubens occurring in the fjord: The black variety which lives only in the low salinity upper waters (22-26/1000) and the red variety which live both in the upper layer and in the deeper layer characterized by a salinity close to that of seawater (30/1000). The studied immune responses were stimulated in starfish living along the metal pollution gradient according to the contamination of these starfish by cadmium. However, the sensitivity of these responses toward metals appeared to be strongly modulated by the salinity stress. In red starfish living at 30/1000 and transferred up the contamination gradient, the immune responses were inhibited and closely followed the short-term accumulation of metals in the animal organs. Starfish transferred down the gradient did not recover normal immune responses in the short-term and appeared highly sensitive to caging stress. It is suggested that the impact of metals on the immune responses of A. rubens in field conditions occurs in three phases. Short-term inhibitory effects are exerted by a direct action of metals on the immune cells and are followed by a recovery due to the induction of protective mechanisms. Eventually, when these mechanisms are overwhelmed by a long-term contamination, indirect and durable stimulatory effects on the immune responses appear due to a global disruption of the animal physiology.

The present study evaluated the effects of field metal contamination on sperm motility and the RNA/DNA ratio in echinoderms. Populations of Asterias rubens and Echinus acutus that occur naturally along a contamination gradient of sediments by cadmium, copper, lead, and zinc in a Norwegian fjord (the Sorfjord) were studied. Sperm motility, a measure of sperm quality, was quantified using a computer-assisted sperm analysis system. The RNA/DNA ratio, a measure of protein synthesis, was assessed by a one-dye (ethidium bromide)/one-enzyme (RNase), 96-well microplate fluorometric assay. Although both species accumulate metals at high concentrations, neither sperm motility parameters in A. rubens nor the RNA/DNA ratio in both species were affected. The Sorfjord is still one of the most metal-contaminated marine sites in Europe, but even so, populations of A. rubens and E. acutus are able to endure under these conditions.

The accumulation of Cd, Pb, Zn, and Cu in the starfish Asterias rubens was studied in a Norwegian fjord characterized by a gradient of metal pollution in the sediments, ranging from very high metal concentrations at its head to much lower levels at its opening. The concentrations of metals in starfish from natural populations along the gradient (long-term accumulation) and in starfish that were transferred up the gradient (short-term accumulation) were compared. At long-term, Cd and Pb accumulations by starfish living at normal salinity (30/1000) were related to the level of contamination of the environment while Cu and, to a lesser extent, Zn accumulations appeared strictly controlled. At short-term, Pb was accumulated steadily, Cd and Zn were accumulated transiently in the pyloric caeca (fast compartment), and Cu was not accumulated at all. Depuration experiments (transfer down the gradient) showed that Cd and Pb were efficiently eliminated from the pyloric caeca but not from the body wall (slow compartment). It is concluded that Pb is chronically accumulated, without apparent control, Cd is subjected to a regulating mechanism in the pyloric caeca which is overwhelmed over the long-term; Zn is tightly controlled in the pyloric caeca and Cu in both pyloric caeca and body wall. A distinct color variety of starfish is restricted to the low salinity (22-26/1000) superficial water layer. This variety showed a different pattern of metal accumulation over the long-term. This pattern is attributed to the particular hydrological conditions prevailing in this upper layer.