Stable isotopes document winter trophic ecology and maternal investment of adult female southern elephant seals (<Emphasis Type="Italic">Mirounga leonina</Emphasis>) breeding at the Kerguelen Islands

Individual specialisation is widespread and can affect a population’s ecological and evolutionary dynamics. Whether intra-specific niche differences can influence reproductive investment was examined in a marine mammal, the southern elephant seal (Mirounga leonina), whose females were known to forage in two different areas during the austral winter. The study was conducted at Kerguelen Islands (49°21′S, 70°18′E), southern Indian Ocean, in late winter–early spring 2006. Pups were used as proxies of their mothers’ biology and combined information on their weaning mass (a proxy of females’ foraging success and short-term fitness) together with their blood δ¹³C value (a proxy of female foraging zone). First, the use of isotopic signature of pups was validated to study the female foraging ecology during their pre-breeding trip by demonstrating that δ¹³C and δ¹⁵N values of pups and their mothers were positively and linearly correlated. Then, blood samples were taken from a large number of newly-weaned pups, which were also weighed, to provide information at the population level. Estimated δ¹³C values of female seals encompassed a large range of values (from −23.7 to −19.1‰) with an unimodal frequency distribution, suggesting no contrasted foraging areas within the population. No significant relationship was found between pup weaning mass and their carbon signature, indicating no link between female foraging areas and maternal foraging success and investment. Finally, blood δ¹³C and δ¹⁵N values gave new insights into southern elephant seal ecology, suggesting that females mainly foraged north of the Polar Front where they preyed upon myctophid fish in late winter.     

Deleterious effects of a nonPST bioactive compound(s) from <Emphasis Type="Italic">Alexandrium tamarense</Emphasis> on bivalve hemocytes

The known negative effects of shellfish toxin-producing dinoflagellates on feeding, burrowing and survival of some bivalve mollusks has prompted questions concerning whether they might also impair the internal defense system of affected bivalves and make them more susceptible to disease agents. The primary components of the cellular defense system are hemocytes. Many toxic dinoflagellates are too large to be ingested whole by hemocytes and would most likely be exposed to intracellular toxins only after the algae are consumed, broken down, and the water-soluble toxins, released. Therefore, we conducted a series of experiments in which hemocytes from two suspension-feeding bivalves—the Manila clam, Ruditapes philippinarum, and the softshell clam, Mya arenaria—were exposed in vitro to filtered extracts of one highly toxic paralytic shellfish toxin (PST)-producing and one nonPST-producing strain of Alexandrium tamarense (isolates PR18b, 76 ± 6 STXeq cell⁻¹ and CCMP115, with undetectable PST, respectively). We measured adherence and phagocytosis, two hemocyte attributes known to be inhibited by bacterial pathogens and other stressors. We found no measurable effect of a cell-free extract from a highly concentrated suspension of the PST-producing strain on hemocytes of either bivalve species. Instead, extract from the nonPST-producing strain had a consistent negative effect on both clams, resulting in significantly lower adherence and phagocytosis compared to strain PR18b and filtered seawater controls. The bioactive compound produced by strain CCMP115, which has yet to be characterized, may be similar to the PST-independent allelopathic compounds described for Alexandrium spp., which act on other plankters. These compounds and those produced by other harmful algae are known to cause immobilization, cellular deformation and lysis of co-occurring target organisms. Thus, nonPST producing Alexandrium spp., which do not cause paralysis and burrowing incapacitation of clams, may still produce a compound(s) that has negative effects not only on hemocytes, but on other molluscan cell types and their functions, as well.     

Can Offshore Wind Energy Be a Lever for Job Creation in France? Some Insights from a Local Case Study

The French government has launched three separate calls for tender in July 2011, March 2013, and December 2016 to install 3.5 GW of offshore wind. In addition to contributing to the fulfillment of environmental commitments, the deployment of offshore wind energy is expected to be a lever for economic development. To assess gross economic impacts, mainly in terms of job creation, we built a regional input-output model of the wind farm off Saint-Brieuc located in the region of Brittany, north-western France. Our model indicates that the project will have positive effects on Brittany’s economy. In particular, during the investment phase, the wind farm is expected to lead to €0.38 M/year/MW of added value and 6.03 full-time equivalent (FTE) jobs/year/MW. During the operation and maintenance (O&M) phase, the model predicts the generation of €0.15 M/year/MW of added value and 1.02 FTE jobs/year/MW. These results imply that the project will increase Brittany’s GDP slightly by 0.22 and 0.09% during the investment and O&M phases, respectively. Results also show that out of total wealth created in France, 38 and 66% will be created in Brittany as well as 32 and 51% of employment during respectively investment and O&M phases. A comparative analysis highlights in particular that economic impacts are generally stronger during the investment phase. It also demonstrates that the magnitude of economic impacts depends on the proportion of local industries in the supply chain. Policy implications of our model stress the need to revise the economic, technological, regulatory, and social frameworks within which the offshore wind industry currently operates in France to establish the conditions necessary for its development.     

Tributyltin and triphenyltin uptake by lettuce

This paper provides quantitative information on the transfer of TBT (tributyltin) and TPhT (triphenyltin) from sludged soil to cultivated lettuce. The effect of their initial concentrations in the soil (varying from 20 to 50 microg(Sn)kg(-1) for each triorganotin), sludge amount (between 1% and 9%), and cultivation duration (32-54 days) was evaluated by means of experimental designs. The impact of the cultivation temperature at 13 degrees C and 19 degrees C on organotin fate in the soil/plant system was also considered. The final concentration of a given organotin in the plant roots was found to depend directly on its initial concentration in the soil. A total of (85+/-15)% of initial TBT in the soil was still present at the end of the experiments, regardless of the cultivation duration. Consequently, TBT appeared to be taken up by lettuce continually. A total of (75+/-5)% of TPhT was found to be degraded in the soil at 54 days. So, this compound could have been taken up by the plant at the beginning of the cultivation. Sludge amount seemed to have a negative effect on TPhT concentration in a plant at 32 days. This could be due to the quantitative TPhT sorption onto the sludge, observed just after spiking. Organotin plant uptake appeared to be more important at 19 degrees C than at 13 degrees C. TBT and TPhT were mainly accumulated in the roots, and up to 2% and 10% of TPhT and TBT, respectively, were translocated to the shoots. Despite TPhT degradation, products in large amounts were present in the soil and were not significantly taken up by the plant. They possibly remained immobilized on solid phases of the sludged soil.     

In Vitro Biodegradation of Polyester-Based Plastic Materials by Selected Bacterial Cultures

A simple and rapid in vitro test was designed for the assessment of the biodegradation of polyester-based plastics by selected biodegrading bacterial strains. Variovorax paradoxus LMG 16137 was used for the degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Acidovorax avenae subsp. avenae LMG 17238 fo the synthetic-based polyesters poly(-caprolactone) (PCL), poly(butylene succinate-co-butylene adipate), and a starch-PCL blend. Degradation by the bacteria was studied in liquid medium with the plastics (films, granules, and injection-molded test bars) as sole sources of carbon. Degradation was followed through gravimetry, growth of the culture, and tensile testing. The effects of incubation time, inoculum density, aeration, incubation temperature, and pH of the medium on the mass loss were investigated and conditions optimized. The test allowed to obtain reproducible results on the mass loss of plastic samples in less than 3 weeks and yielded excellent partially degraded samples for further analysis.     

“Decision-making” in conflicts of wild chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>): an extension of the Relational Model

>We examined the "decision-making" process of aggressive interactions within a community of wild chimpanzees (Pan troglodytes verus) in the Taï National Park, Côte d'Ivoire (West Africa). Costs and benefits were investigated for 876 dyadic aggressive interactions among 18 adults (including 4 independent adolescents) of either sex. An extended version of the Relational Model was developed to describe the dynamics of the "decision-making" process in Taï chimpanzees, which suggests that the net benefit determines the occurrence of conflicts. Both sexes fought more frequently for the resources that were most important to them, food for females and social contexts for males. Individuals used two different strategies according to their likelihood of winning the aggressive interaction, determined by the dominance relationship of the conflict partners. Dominant initiators had longer and more intense aggressive interactions, but they limited their social disadvantages by fighting non-cooperative partners. Subordinate initiators had shorter and less intense aggressive interactions, but risked more social costs, which they could reduce afterwards by reconciliation. Both strategies included a positive overall net benefit. The extended Relational Model fits the complexity of wild chimpanzee conflicts and allows for more flexibility in the "decision-making" compared to the original version.Communicated by E. Sterck     

The determination of fluoride in water in the presence of organic acids and iron using a fluoride-selective electrode

Surface waters in Scotland, notably from upland catchment areas, are commonly enriched in iron and organic acids. This study investigated the impact of these species on the direct potentiometric determination of fluoride using a fluoride-selective electrode. As the electrode technique is commonly used to monitor the fluoride content of potable waters, it is important that these effects are evaluated if such waters are to be fluoridated. The determination method used was that defined by Nicholson (1983) and Nicholson and Duff (1981) to minimise errors. This employs the TISAB III-TAC buffer system with the following composition (in 1L): 58.0 g sodium chloride, 57.0 mL glacial acetic acid, 4.0 g CDTA, 243.0 g tri-ammonium citrate adjusted to pH 5.4 with 10 M sodium hydroxide. Experimental solutions of fluoride with organic acid or iron were prepared, and the effect on fluoride concentration determined for each combination. Concentrations used: fluoride: 0.1, 1.0 mg L⁻¹; humic acid: 5, 10, 100, 1000, 10,000 mg L⁻¹; oxalic acid: 5, 10, 100, 1000, 10,000 mg L⁻¹; iron(III): 1, 10, 100, 500 mg L⁻¹; Humic acid (HA) concentrations had no impact on the determination of fluoride at the 1.0 mg L⁻¹ level. However, with 0.1 mg L⁻¹; F⁻, an increase in the apparent fluoride concentration was observed when HA > 1,000 mg L⁻¹; this increased with increasing HA content to a maximum of ∼600%. Oxalic acid (OA) generally had no impact on the fluoride determinations at the 1.0 mg L⁻¹; level, but at an OA concentration of 10,000 mg L⁻¹; fluoride concentrations were reduced by ∼50%. At 0.1 mg L⁻¹ F⁻, increasing OA concentrations produce a steady increase in the fluoride concentration of up to 200% with 1,000 mg L⁻¹; OA, greater OA contents produce a fall in the fluoride content. Iron had no effect on the fluoride determinations at both the 0.1 and 1.0 mg L⁻¹ levels. The causes of the apparent increases in fluoride concentration have not been determined, although fluoride contamination by the reagents has been ruled-out. However, the results demonstrate that the defined method and buffer system is suitable for the determination of fluoride in the presence of iron and organic acids at naturally occurring levels, and that fluoride will not be masked from detection.     

Bisexually bonded ranging in chimpanzees (Pan troglodytes verus)

Abstact While male mammals seek to maximize access to potential mates, females maximize feeding efficiency. Ranging patterns are therefore often sex specific. Sex-specific ranging patterns have also been reported for East African chimpanzees and a recent study on female ranging patterns concludes that social organization is best described by a male-bonded community model, where females occupy individual home ranges that are distributed within the boundaries of the male-defended range. In West African chimpanzees, however, such sex-specific ranging patterns have not been consistently observed and a bisexually bonded community model, where both sexes use the entire home range equally, has been suggested to best describe social organization. In this study we analyze 5 years of data on individual ranging patterns of chimpanzees in the Taï National Park (Côte dIvoire) to test specific predictions of the different models of chimpanzee social organization. We found that although males in Taï had slightly larger home ranges than females, all individual home ranges and core areas overlapped highly. Small individual home range size differences were entirely due to the use of peripheral areas and were correlated with female social dominance. These findings strongly support the bisexually bonded community model for Taï chimpanzees. Thus, we conclude that there are fundamental differences in the space-use patterns of East and West African chimpanzees and discuss possible factors leading to such differences.Communicated by D. Watts     

Determining the influence of the physicochemical parameters of urban soils on As availability using chemometric methods: A preliminary study

An initial exploration was conducted using mathematical and statistical methods to obtain relevant information about the determination of the physicochemical parameters capable of controlling As uptake by ryegrass grown on contaminated topsoils.Concentrations of As in the soils were from 10 to 47 mg/kg,mainly in the As(V) form(57%–73%).Concentrations of As in water extracts were very low(61–700 μg/kg).It was suggested that As(Ⅲ) was mainly in the uncharged species and As(V) in the charged species.Chemometric methods revealed that the values of the ratio As(Ⅲ)/As(V) depended on the assimilated-phosphorus,the pseudo-total and water-extractable Fe contents and the soil p H.Arsenic concentrations measured in ryegrass shoots ranged from 119 to 1602 μg/kg.Positive linear correlations were obtained between As in ryegrass shoots and water extractable-As.The transfer coefficient of As correlated well with the ratio assimilated-phosphorus/Fe-oxides.As(Ⅲ)uptake by the shoot of ryegrass was controlled by the organic matter and Fe-oxide contents.