Barrage fishponds,a funnel effect for metal contaminants on headwater streams

Fishponds are man-made shallow water bodies that are still little studied because of their small size. They represent high value ecosystems, both environmentally (biodiversity hotspot) and economically (fish production). They can have a high place on the hydrographic network, so their influence on water quality is of first importance for rivers and water bodies located downstream and monitored under the Water Framework Directive. These small water bodies can be a source of contaminants during draining period or an efficient buffer for pesticides. We wanted to evaluate whether these ponds could also be a remediation tool against metals by following the annual evolution of upstream/downstream flows. Cadmium, copper, lead and zinc concentrations were quantified in the dissolved phase upstream and downstream of three ponds, each one having a specific agricultural environment (traditional or organic). Metal concentration was quantified in sediments and water. For the dissolved phase, the predictive non-effect concentration was often exceeded, suggesting an environmental risk. Results highlighted also greater quantity of metals at the downstream of the pond compared to the upstream, suggesting remobilization into the ponds or direct cross-sectional contributions from the watershed (e.g. runoff from crops) or even remobilization. Regarding sediments, minimal contamination was shown but a high mineralogical variability. No buffer effect of ponds, which could reduce the risk of acute or chronic toxicity, was detected.

     

Indoor Nitrogen Dioxide Exposure and Children’s Pulmonary Function

Elevated concentrations of nitrogen dioxide (NO₂) are produced in the home by the use of unvented gas appliances. In studies on potential health effects of Indoor exposure to NO₂, exposure has mostly been estimated from the presence or absence of sources like gas cookers in the home. This leads to misclassification of exposure, as NO₂ concentrations in the home depend also on source use, ventilation habits, time budgets, etc. The availability of cheap, passive monitoring devices has made it possible to measure Indoor concentrations of NO₂ directly in health effects studies, albeit with averaging times of one to several days. So far, it has not been evaluated whether this increases the sensitivity of a study to detect health effects of NO₂. In this paper, a comparison is made between NO₂ sources and weekly average indoor NO₂ measurements, as predictors of pulmonary function in a study among children aged 6–12 years.

The relationship between exposure and lung functions was found to be generally non-significant in this study. The results further suggested that in this study, measuring Indoor NO₂ concentrations with passive monitors offered no advantage over the simple use of source presence as exposure variable.     

Sellers' Hedging Incentives at EPA's Emission Trading Auction

Cason (1993, J. Environ. Econom. Management25, 177–195, doi:10.1006/jeem 1993.1041) argued that the auction which the EPA used in order to start the market for sulfur allowances may reduce the efficiency of the market since it gives sellers an incentive to understate their valuation. In this paper we show that the sellers' incentives are even more perverse than Cason suggested when we take into account that sellers can also submit a bid. We show that sellers have an incentive to set their asking price equal to 0 while simultaneously hedging their bets by submitting a positive bid.     

Working safely with foreign contractors and personnel

Foreign companies and personnel are increasingly being employed for risky activities in process industry (Agro, Gas and Chemicals) in the north of the Netherlands. Against the backdrop of these developments, the need arose within the ‘VGM Noord-Nederland’ cooperation (health, safety and the environment in the Northern Netherlands) to further investigate experienced and detected problems, possible explanations, solutions and directions for preventing unsafe situations when working with foreign contractors and personnel. Because of little scientific information available on the topic, in autumn of 2004 an exploratory study was conducted into ‘working with foreign contractors and personnel’ in the process industry in the northern Netherlands under the auspices of VGM Noord-Nederland. In the course of the study, ten qualitative interviews were held with safety experts working at multinational companies in the agro, gas and chemical industry in the Northern Netherlands. The objective of the study was to gain sharper insight into the common problems and best practices experienced by these companies when working with foreign contractors and personnel in order to focus future joint activities towards these problematic areas. The study resulted in the identification of five problematic areas: communication, level of education, cultural differences, specific employment situations and cooperation between principal and contractor. All of these factors can be located within the ‘latent failure types’ or ‘basic risk factors’ described by the well known Tripod Model (i.e. Groeneweg, J., Lancioni, G.E., Metaal, N., 2002. Motivating for Safety, Leading by Example: moving from Compliance to Competence, Profshore Management Motivation Module, Stavanger) of accident causation. The results of the interviews are described for each problem area individually and are linked to state of the art scientific theory and models. Directions for ‘best practice’ examples are given and an indication for follow-up action is made.     

“Food Metaphors and Ethics: Towards More Attention for Bodily Experience”

Official Dutch food information apparently tries to avoid images but is implicitly shaped by the metaphor that food is fuel. The image of food as fuel and its accompanying view of the body as a machine are not maximally helpful for integrating two important human desires: health and pleasure. At the basis of the split between health and pleasure is the traditional mind–body dichotomy, in which the body is an important source of evil and bodily pleasure is sinful and dangerous. In the search for alternatives, new metaphors are proposed that integrate mind and body as well as pleasure and health. The relevance of metaphors for ethics is at least twofold. (1) Moral thought and theory are at least partly shaped by metaphors. In the light of this growing recognition, the analysis of morality needs innovation. (2) With regard to food, new metaphors, such as slow food, or the image of enjoyment as an art, enable a new search for morally responsible forms of hedonism, based on more love and respect for human as well as animal bodies. But new metaphors are specific and selective, just like old ones. I argue that a search for the best overall metaphor would be misguided, but that more diverse forms of attention to bodily aspects of life, including experiences related to food, will result in richer vocabularies of the body, the mind, and body–mind relations. This holds a promise of moral progress.     

Inter-sexual differences in T-cell-mediated immunity of black-headed gull chicks (<Emphasis Type="Italic">Larus ridibundus</Emphasis>) depend on the hatching order

Hatching asynchrony in avian species leads to age and size differences between nestlings within a brood, handicapping last-hatched chicks in the sibling rivalry. Starvation due to this competitive disadvantage has been regarded as the primary cause of an increase in mortality with hatching order. However, for gulls it has also been suggested that disease is the cause of mortality for last-hatched chicks, possibly through reduced immunocompetence and thereby an enhanced susceptibility to infection. In addition, the male-biased mortality reported for several gull species may be related to a higher vulnerability to diseases in males compared to females. To determine the potential influence of the immune system on these mortality patterns, we investigated the T-cell-mediated immunity (CMI) of black-headed gull chicks in relation to hatching order and sex. We found a significant decrease in the CMI with hatching order. This result may be causally related to systematic changes in maternal yolk steroids and carotenoids within the laying sequence. For second-laid eggs, male CMI was significantly lower than female CMI. This is possibly linked to higher plasma levels of testosterone in male embryos which might have an immunosuppressive effect. If so, this effect is masked in eggs of either high (first egg) or low (last egg) quality. Chicks with low CMI showed enhanced mortality rates. Thus the differences in immune response are likely to contribute to the observed mortality patterns. However, hatching order significantly affected mortality independently of CMI, suggesting that competitive disadvantage due to hatching asynchrony is also important.Communicated by M. Webster     

Social stimulation,nuptial colouration,androgens and immunocompetence in a sexual dimorphic cichlid fish

The nature of the costs maintaining honesty of sexual signalling in inter- and intrasexual interactions remains a contentious issue. For carotenoid-based colour ornaments, it has been hypothesized that the honesty of the signal is enforced when carotenoid allocation to colour expression is traded off against carotenoid availability for immunocompetence. In addition, honesty is enforced if androgens required for colour expression are immunosuppressive. We tested whether there is a trade-off between colour expression and immunocompetence in a lek-breeding haplochromine cichlid fish, Pundamilia nyererei, from Lake Victoria with a carotenoid-based nuptial dress. First, we showed that expression of red nuptial colouration and social rank in a group were positively correlated. We then successfully manipulated the level of colour advertisement by socially stimulating individually housed males with a rival male: Stimulated males developed larger areas of red nuptial colouration and had higher levels of circulating 11-ketotestosterone (11-KT) than non-stimulated males. We subsequently tested the humoral immune response to a novel antigen (sheep red blood cells). There was no overall significant effect of social stimulation on antibody production, but in the stimulated males, the degree of red colouration and the antibody response were negatively correlated. This significant interaction between colour and treatment thus shows that the negative correlation between colouration and antibody production is dependent on the (manipulated) social environment. This study provides correlational and experimental evidence for a trade-off between expression of a sexual trait and one component of immune function in fish. We found no evidence for a direct effect of 11-KT on antibody production, and we discuss alternative mechanisms that could mediate the trade-off.     

Sex-specific energy requirements in nestlings of an extremely sexually size dimorphic bird, the European sparrowhawk (Accipiter nisus)

Allocation of parental investment is predicted to be equal at the population level between both sexes of offspring, and should lead to sex ratio biases in species that exhibit a sex-difference in parental care. Sex-differences in parental care are rarely quantified. We measured daily energy expenditure in free-living nestlings of the extremely sexually size dimorphic European sparrowhawk (Accipiter nisus), using the doubly labelled water method. These data were combined with measured growth characteristics to estimate daily and total metabolised energy intake of male and female young during the nestling stage. Females reached an asymptotic body mass 1.6 times higher than males. This resulted in a total metabolised energy an estimated 1.4 times higher for the nestling stage. Furthermore, we observed a decline in daily metabolised energy with an increase in brood size, which was significantly stronger for females than for males. These results are discussed in the context of Fishers equal allocation theory. Empirical evidence of a sex ratio bias at the end of parental care, with an overall excess of males, is lacking in this species. Consequently, our data do not support the idea of equal allocation between the sexes. The observed sex difference in daily metabolised energy in response to brood size may give scope for sex ratio bias at the level of the individual brood.     

A strategy for the next decade to address data deficiency in neglected biodiversity

Measuring progress toward international biodiversity targets requires robust information on the conservation status of species, which the International Union for Conservation of Nature (IUCN) Red List of Threatened Species provides. However, data and capacity are lacking for most hyperdiverse groups, such as invertebrates, plants, and fungi, particularly in megadiverse or high-endemism regions. Conservation policies and biodiversity strategies aimed at halting biodiversity loss by 2020 need to be adapted to tackle these information shortfalls after 2020. We devised an 8-point strategy to close existing data gaps by reviving explorative field research on the distribution, abundance, and ecology of species; linking taxonomic research more closely with conservation; improving global biodiversity databases by making the submission of spatially explicit data mandatory for scientific publications; developing a global spatial database on threats to biodiversity to facilitate IUCN Red List assessments; automating preassessments by integrating distribution data and spatial threat data; building capacity in taxonomy, ecology, and biodiversity monitoring in countries with high species richness or endemism; creating species monitoring programs for lesser-known taxa; and developing sufficient funding mechanisms to reduce reliance on voluntary efforts. Implementing these strategies in the post-2020 biodiversity framework will help to overcome the lack of capacity and data regarding the conservation status of biodiversity. This will require a collaborative effort among scientists, policy makers, and conservation practitioners.     

High natural fusion rates in a botryllid ascidian

Many benthic colonial invertebrates have the ability to fuse and form chimeras with compatible colonies. Botryllid ascidians are model organisms for the study of the evolution of and molecular basis for allorecognition, and fusion rates have been determined for different populations and species by random sampling and fusion testing between individuals. However, natural fusion rates over time have not been documented. Nine settlement panels were deployed in Salem Harbor, Massachusetts, USA and Botrylloides violaceus settlement, growth, and fusion monitored from July to mid-August 2007. Seventy-three percent of the recruits observed fused with at least one other colony, while 4% neither fused nor were overgrown. Multifused colonies were not observed to grow faster than single colonies when growth was calculated as increase in size beyond the summation of fused entities; however, they were significantly larger. These results suggest that larvae settle in clumps of compatible individuals, and that large subtidal colonies may be the result of high numbers of fusions between compatible colonies.