(Table 1) Body condition and plasma POP concentrations of glaucous gulls from Bjørnøya, Svalbard archipelago

Behavioural field observations are increasingly being used in ecotoxicological research to identify potential adverse effects of exposure to persistent organic pollutants (POPs). We investigated thermal conditions inside the nest and parental behaviour of glaucous gulls, Larus hyperboreus, breeding in the Norwegian Arctic in relation to the concentrations of major classes of POPs (organochlorines, brominated flame retardants and metabolically derived products) accumulated in their blood. Most notably, nest temperature was negatively correlated with the concentrations of the sum of DDT, sum of PCB and several quantitatively minor POP classes within the incubating parent. To investigate the relationship between incubation ability and parental POP exposure further, we experimentally increased the costs of incubation by artificially increasing the clutch size from two to four eggs. Clutch enlargement was followed by a decrease in nest temperature, but this drop in temperature was not associated with POP concentrations within the incubating parent. However, males, which had higher POP concentrations and lower white blood cell counts than females, seemed less able to maintain nest temperature. There was virtually no evidence to suggest that the sum of PCB or DDT were associated with changes in the time a bird spent incubating. However, there was some indication that nest site attendance by nonincubating males was negatively related to the sum of DDT, suggesting that nest protection may have been compromised. The results suggest that adverse effects of parental POP exposure may occur through suboptimal thermal conditions for embryo development and possibly increased egg predation risk.

Agricultural pesticide in sediment cores from the Lac de Saint-André, France

Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change.

Evaluation of the threat of marine CO2 leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves

The effects of the acidification associated with CO2 leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO2-induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO2-bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1; pH 6.6; pH 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 and 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO2 and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves.

Seawater carbonate chemistry and trace element accumulation during experiments with common cuttlefish, Sepia officinalis, 2009

Cephalopods play a key role in many marine trophic networks and constitute alternative fisheries resources, especially given the ongoing decline in finfish stocks. Along the European coast, the eggs of the cuttlefish Sepia officinalis are characterized by an increasing permeability of the eggshell during development, which leads to selective accumulation of essential and non-essential elements in the embryo. Temperature and pH are two critical factors that affect the metabolism of marine organisms in the coastal shallow waters. In this study, we investigated the effects of pH and temperature through a crossed (3?2; pH 8.1 (pCO2, 400 ppm), 7.85 (900 ppm) and 7.6 (1400 ppm) at 16 and 19°C, respectively) laboratory experiment. Seawater pH showed a strong effect on the egg weight and non-significant impact on the weight of hatchlings at the end of development implying an egg swelling process and embryo growth disturbances. The lower the seawater pH, the more 110 mAg was accumulated in the tissues of hatchlings. The 109Cd concentration factor (CF) decreased with decreasing pH and 65Zn CF reached maximal values pH 7.85, independently of temperature. Our results suggest that pH and temperature affected both the permeability properties of the eggshell and embryonic metabolism. To the best of our knowledge, this is one of the first studies on the consequences of ocean acidification and ocean warming on metal uptake in marine organisms, and our results indicate the need to further evaluate the likely ecotoxicological impact of the global change on the early-life stages of the cuttlefish.