Note--On the Timing of Greenhouse Gas Emissions Reductions: A Final Rejoinder to the Symposium on "The Economics of Climate Change: The Stern Review and its Critics"

In this final rejoinder to the symposium on "The Economics ofClimate Change: The Stern Review and Its Critics," we respondto comments published in the last issue of this journal by RobertMendelsohn, Thomas Sterner and U. Martin Persson, and John P.Weyant (Mendelsohn et al. 2008). In particular, we examine thepoint of debate with arguably the greatest practical importancefor ongoing negotiations over an international agreement tosucceed the Kyoto Protocol: namely the appropriate timing ofglobal reductions in greenhouse gas emissions. Too often in the past, this debate has been presented as onebetween the poles of "act now" and "wait-and-see". Weyant (seeWeyant's     

Methyl tert-butyl ether (MTBE) in finished drinking water in Germany

In the present study 83 finished drinking water samples from 50 cities in Germany were analyzed for methyl tert-butyl ether (MTBE) content with a detection limit of 10 ng/L. The detection frequency was 46% and the concentrations ranged between 17 and 712 ng/L. Highest concentrations were found in the community water systems (CWSs) of Leuna and Spergau in Saxony-Anhalt. These CWSs are supplied with water possibly affected by MTBE contaminated groundwater. MTBE was detected at concentrations lower than 100 ng/L in drinking water supplied by CWSs using bank filtered water from Rhine and Main Rivers. The results from Leuna and Spergau show that large groundwater contaminations in the vicinity of CWSs pose the highest risk for MTBE contamination in drinking water. CWSs using bank filtered water from Rhine and Main Rivers are susceptible to low MTBE contaminations in finished drinking water. All measured MTBE concentrations were below proposed limit values for drinking water.     

Organochlorine and organophosphorous pesticide residues in the Ouémé River catchment in the Republic of Bénin

The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.     

Contamination of fish by organochlorine pesticide residues in the Ouémé River catchment in the Republic of Bénin

In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.     

Remote Antarctic feeding ground important for east Australian humpback whales

Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales.     

Poecilogony in Polydora hoplura (Polychaeta: Spionidae) from commercially important molluscs in South Africa

Females of the polychaete Polydora hoplura (Claparède 1869) that produced planktotrophic and adelphophagic larvae were compared genetically to determine whether the different reproductive morphs represented sibling species or poecilogony. Worms were collected from Saldanha Bay, South Africa (33°0′37.71S, 17°56′59.74E), and cultured in a laboratory setting from November 2012 to April 2013. The results based on mitochondrial and nuclear DNA (Cyt b and ATPSα, respectively) showed shared haplotypes between reproductive morphs for both markers. Additionally, variation in mtDNA sequences was significantly higher within morphs than between morphs (95.8 and 4.2 %, respectively). A comparison of developmental modes found that broods of planktotrophic larvae were larger than broods of adelphophagic larvae, while the latter had larger eggs and larvae at hatching. Developmental time from oviposition to settlement for planktotrophic and adelphophagic larvae was 40.2 and 16.6 days, respectively. Polydora hoplura represents the fifth confirmed case of poecilogony in the Spionidae.     

Bio-Based Polymers and End-of-Life Vehicles

As new materials, such as bio-based plastics and composites, are introduced in vehicles for their improved environmental performance, it is necessary to understand how to efficiently recover these biodegradable materials. This paper provides an overview of the end-of-life phase for automobiles, focusing on the dismantling and shredding processes, and the recovery of materials. Targeted unit operations, such as dismantling of components from vehicles and pretreatment prior to shredding, along with design-for-environment principles, should enable the efficient recovery of materials at the end-of-life phase compared with popularly conceived all-in-one-approaches because of the diverse arrangement of material components.     

Production of food-associated calls in wild male chimpanzees is dependent on the composition of the audience

Chimpanzees produce acoustically distinct calls when encountering food. Previous research on a number of species has indicated that food-associated calls are relatively widespread in animal communication, and the production of these calls can be influenced by both ecological and social factors. Here, we investigate the factors influencing the production of food-associated calls in wild chimpanzees and examine whether male chimpanzees produce food-associated calls selectively in the presence of important social partners. Male chimpanzees form stable long-term social relationships with each other, and these social bonds are vital in enabling a range of cooperative activities, such as group hunting and territory defence. Our data show that males were significantly more likely to produce food-associated calls if an important social partner was nearby, regardless of the size of the audience or the presence of oestrus females. Call production was also mediated by the size of the food patch and by whether or not the food could be monopolised. The presence of important social partners explained most of the variation in male calling behaviour, indicating that food-associated calls are socially directed and serve a bonding function.     

Alteration of cuticular hydrocarbon composition affects heterospecific nestmate recognition in the carpenter ant Camponotus fellah

Nestmate recognition is a ubiquitous phenomenon in social insects as a means to prevent entry of undesired individuals aiming at exploiting the rich nest resources. The recognition cues in ants were shown in a few cases to be cuticular hydrocarbons, although there are a quite number of correlated associations. In the present study we modified the cuticular profiles of workers Camponotus fellah hydrocarbons with cuticular washes from a closely related, yet undescribed species, Camponotus sp. Although these sympatric species are morphologically indistinguishable, cuticular washes of C. sp. contain 9,13-dimethylpentacosane and 11,15-dimethylheptacosane that are either absent or occur as traces in C. fellah. In addition, C. sp. contains significantly greater amounts of 3-methylpentacosane than C. fellah workers. The cuticle modification was done solventless in a manner that minimized disruption to the cuticular structure of the ant being modified. Judging from the 3 focal compounds, such treatment added between 20 and 30% of the original amounts present in C. sp. to the treated C. fellah workers. This addition changed consistently the cuticular hydrocarbon profile of the treated ant. Dyadic assays between C. fellah and their nestmates treated with C. sp. cuticular rinses revealed a significantly higher level of aggression compared to non-treated nestmates. There was no aggression between nestmates of C. sp. These results demonstrate that in heterospecific interactions between the two Camponotus species there is a correlation between cuticular hydrocarbons and a nestmate recognition response, albeit not as high as the response of C. fellah to of C. sp. workers. This is consistent with the hypothesis that cuticular hydrocarbons may play a role in nestmate recognition.     

Modelling the effects of trade-offs between long and short-term objectives in fisheries management

Fisheries management is typically a complex problem, from both an environmental and political perspective. The main source of conflict occurs between the need for stock conservation and the need for fishing community well-being, which is typically measured by employment and income levels. For most fisheries, overexploitation of the stock requires a reduction in the level of fishing activity. While this may lead to long-term benefits (both conservation and economic), it also leads to a short-term reduction in employment and regional incomes. In regions which are heavily dependent on fisheries, short-term consequences of conservation efforts may be considerable. The relatively high degree of scientific uncertainty with respect to the status of the stocks and the relatively short lengths of political terms of office, generally give rise to the short-run view taking the highest priority when defining policy objectives. In this paper, a multi-objective model of the North Sea is developed that incorporates both long-term and short-term objectives. Optimal fleet sizes are estimated taking into consideration different preferences between the defined short-term and long-term objectives. The subsequent results from the model give the short-term and long-term equilibrium status of the fishery incorporating the effects of the short-term objectives. As would be expected, an optimal fleet from a short-term perspective is considerably larger than an optimal fleet from a long-run perspective. Conversely, stock sizes and sustainable yields are considerably lower in the long-term if a short-term perspective is used in setting management policies. The model results highlight what is essentially a principal-agent problem, with the objectives of the policy makers not necessarily reflecting the objectives of society as a whole.