Toxicity of the mosquito control pesticide Scourge to adult and larval grass shrimp (Palaemonetes pugio)

This study investigated the toxicity of various concentrations of technical resmethrin and Scourge on adult and larval Palaemonetes pugio, a common grass shrimp species. Two types of tests were conducted for each of the resmethrin formulations using adult and larval grass shrimp life stages, a 96-h static renewal aqueous test without sediment, and a 24-h static nonrenewal aqueous test with sediment. For resmethrin, the 96-h aqueous LC50 value for adult shrimp was 0.53 microg/L (95% confidence interval (CI): 0.46-0.60 microg/L), and for larval shrimp was 0.35 microg/L (95% CI: 0.28-0.42 microg/L). In the presence of sediment, technical resmethrin produced a 24-h LC50 value for adult shrimp of 5.44 microg/L (95% CI: 4.52-6.55 microg/L), and for larval shrimp of 2.15 microg/L (95% CI: 1.35-3.43 microg/L). For Scourge, the 96-h aqueous LC50 for adult shrimp was 2.08 microg/L (95% CI: 1.70-2.54 microg/L), and for larval shrimp was 0.36 microg/L (95% CI: 0.24-0.55 microg/L). The 24-h sediment test yielded an LC50 value of 16.12 microg/L (95% CI: 14.79-17.57 microg/L) for adult shrimp, and 14.16 microg/L (95% CI: 12.21-16.43 microg/L) for larvae. Adjusted LC50 values to reflect the 18% resmethrin concentration in Scourge are 0.37 microg/L (adult), 0.07 microg/L (larvae) for the 96-h aqueous test, and 2.90 microg/L (adult), 2.6 microg/L (larvae) for the 24-h sediment test. Larval grass shrimp were more sensitive to technical resmethrin and Scourge than the adult life stage. The results also demonstrate that synergized resmethrin is more toxic to P. pugio than the nonsynergized form, and that the presence of sediment decreases the toxicity of both resmethrin and Scourge.     

Beat frequency of cilia in the branchial basket of the ascidian Ciona intestinalis in relation to temperature and algal cell concentration

To elucidate the effects of temperature and algal cell concentration on pumping of water in the ascidian Ciona intestinalis a number of different experiments were performed. Beat frequency of the lateral cilia in the openings of the branchial sac was measured in intact specimens using a microprojection objective and a monochrome CCD video camera. At constant low algal cell concentration, beat frequencies increased linearly with temperature from 4.0 Hz (±0.5) at 7.4 °C to 13.6 Hz (±1.6) at 20.1 °C. At a constant temperature of 15 °C, beat frequency decreased with increasing algal cell concentration from approximately 3000 to >10 000 Rhodomonas sp. cells ml⁻¹. The decrease was observed both in experiments where the ascidians had been acclimated to a fixed algal cell concentration and in experiments with changing concentrations. Effect of algal cell concentration on squirting/siphon closure and flow velocity in the exhalent siphon was measured using a thermistor. At low algal cell concentrations, flow velocity in the exhalent siphon was stable, apart from a few short squirts. At very high algal cell concentrations, the flow velocity was reduced and much less stable, with prolonged squirting. The effect of gut content on filtration was studied in experiments with specimens acclimated to high algal cell concentrations. Results showed a close relation between gut clearance and filtration rate. From the experimental results and a qualitative analysis of the Ciona-pump it was concluded that the ciliary beat frequency is proportional to the water flow through the sea squirt and that changes in pumping caused by temperature or algal cell concentration are under nervous control or governed by enzyme kinetics, rather than being a result of physico-mechanical properties, i.e. pump efficiency versus flow resistance, of the ascidian pump. Received: 6 October 1997 / Accepted: 8 October 1998     

Big society,little justice? Community renewable energy and the politics of localism

This paper challenges “Big Society (BS) Localism”, seeing it as an example of impoverished localist thinking which neglects social justice considerations. We do this through a critical examination of recent turns in the localist discourse in the UK which emphasise self-reliant communities and envisage a diminished role for the state. We establish a heuristic distinction between positive and negative approaches to localism. We argue that the Coalition Government's BS programme fits with a negative localist frame as it starts from an ideological assumption that the state acts as a barrier to community-level associational activity and that it should play a minimal role. “BS localism” (as we call it) has been influential over the making of social policy, but it also has implications for the achievement of environmental goals. We argue that this latest incarnation of localism is largely ineffective in solving problems requiring collective action because it neglects the important role that inequalities play in inhibiting the development of associational society. Drawing upon preliminary research being undertaken at the community scale, we argue that staking environmental policy success on the ability of local civil society to fill the gap left after state retrenchment runs the risk of no activity at all.     

Genealogical relationships within and among shallow-water <Emphasis Type="Italic">Ciona</Emphasis> species (Ascidiacea)

In spite of historical and current interest in Ciona intestinalis and its congeners, little is known about evolutionary relationships among the members of the genus Ciona. Here 744-bp sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene are used to examine phylogenetic relationships among three described species (C. intestinalis, C. roulei, C. savignyi) sampled from multiple coastal sites in the Northeast Pacific (CA, USA), Northwest Atlantic (from New Hampshire to Connecticut, USA), Northeast Atlantic (Sweden and The Netherlands), and Mediterranean (Banyuls-sur-Mer, France). The samples were collected in June–October 2005. The COI sequences of Northeast Pacific/Mediterranean (Type A) and Northwest Atlantic (Type B) C. intestinalis differ by ∼12% and C. roulei is nested within Type B C. intestinalis. Ciona savignyi differs from all other haplotypes by 13–16%. A previously undescribed but morphologically distinct Ciona sp. found at the Banyuls-sur-Mer site was >10% divergent from all other haplotypes. Although these data arise from a single gene study, they indicate that further elucidation of species relationships within the genus and of the species’ distributions will be needed if continuing invasions and potential reproductive isolation are to be investigated.     

Secretor Status is Associated with Susceptibility to Disease in a Large GII.6 Norovirus Foodborne Outbreak

Food and Environmental Virology - Norovirus is commonly associated with food and waterborne outbreaks. Genetic susceptibility to norovirus is largely dependent on presence of histo-blood group...     

Early sonographic diagnosis of body stalk anomaly

Ultrasonographic features of a fetus at 18 weeks of gestation suggesting a body stalk anomaly are presented. These included a large abdominal anterior wall defect in apparent continuity with the placenta, severe kyphoscoliosis of the lower spine, the absence of one kidney, and a very short umbilical cord with only one umbilical artery. The amniotic fluid was reduced and the fetus was almost immobile at short-interval ultrasound examinations. The pregnancy was terminated and autopsy of the fetus showed abnormalities compatible with maldevelopment of both cephalic and caudal embryonic folds.     

Mixture toxicity of the antifouling compound irgarol to the marine phytoplankton species Dunaliella tertiolecta

This study examined the toxicity of irgarol, individually and in binary mixtures with three other pesticides (the fungicide chlorothalonil, and the herbicides atrazine and 2,4-D), to the marine phytoplankton species Dunaliella tertiolecta. Standard 96-h static algal bioassays were used to determine pesticide effects on population growth rate. Irgarol significantly inhibited D. tertiolecta growth rate at concentrations > or = 0.27 micro g/L. Irgarol was significantly more toxic to D. tertiolecta than the other pesticides tested (irgarol 96 h EC50 = 0.7 micro g/L; chlorothalonil 96 h EC50 = 64 micro g/L; atrazine 96 h EC50 = 69 micro g/L; 2,4-D 96 h EC50 = 45,000 micro g/L). Irgarol in mixture with chlorothalonil exhibited synergistic toxicity to D. tertiolecta, with the mixture being approximately 1.5 times more toxic than the individual compounds. Irgarol and atrazine, both triazine herbicides, were additive in mixture. The toxicity threshold of 2,4-D was much greater than typical environmental levels and would not be expected to influence irgarol toxicity. Based on these interactions, overlap of certain pesticide applications in the coastal zone may increase the toxicological risk to resident phytoplankton populations.     

Irrigation canals as tools for climate change adaptation and fish biodiversity management in Southern France

This paper is based on the interdisciplinary research conducted in the south of France that analyses the different economic, social and environmental roles played by agricultural irrigation canals. We argue that beyond their productive role, which is to supply farmers with water, they fulfil other environmental services and play an important role in the context of future climate change to face challenges of adaptation. We point up several ecosystem services provided by such canals, e.g. replenishing the groundwater table, the development of riparian vegetation and wet areas in the Mediterranean zone, tools for regulating flooding and drought, the bases for new cultural approaches to nature. Moreover, they play an important role in the maintenance of an ichthyological biodiversity that is indispensable for the persistence of natural ecosystem. Functioning as an ecological corridor, they display interesting capacities as refuges for certain fish species under stress. Indeed, they can potentially connect upstream and downstream zones over a continuum of more than 300 km and thus covering very contrasted climatic zones (alpine versus Mediterranean). For now, most of these services remain largely unknown and underestimated. However, they serve as assets for territorial development since they combine economic, ecological and social factors whose remodelling is becoming increasingly necessary in the face of climate change.     

Opening access to the black box: The need for reporting on the global phosphorus supply chain

Phosphorus (P) is an essential macronutrient in agriculture; however, lack of reporting makes its supply chain a black box. By using literature synthesis on the P challenge, we identify four areas where the reporting process is problematic: P reserves and resources; P losses along the supply chain; P externalities; and access to data. We find that in these areas, the reporting system is inconsistent, inaccurate, incomplete, fragmented and non-transparent. We use systems analysis to discuss implications of reporting on the sustainability of the P supply chain. We find that reporting is essential for the achievement of global P governance and the human right to adequate food. It can also inform decision makers and other impacted stakeholders on policies on agriculture, food security, pollution and international conflict. An improved P reporting process also allows a better evaluation of global sustainability commitments such as the United Nations Sustainable Development Goals.