Environmental variability and fledging body mass of Common Guillemot Uria aalge chicks

To gain a better understanding of population processes and in the light of the critically endangered status of the Common Guillemot Uria aalge in Norway, we investigate which environmental factors might affect the fitness of guillemot chicks as they depart from the nest site over a 16-year period on a colony in NE Norway. Although prey composition did not seem to influence the fledging body mass of the chicks, there were significant relationships between the yearly variations in chick body mass and abundance of two important prey species (1-group herring Clupea harengus that is an important chick food item and 0-group cod Gadus morhua that is an important adult food item), population size and the sea surface temperature around the colony. The positive influence of young herring and cod on Common Guillemot chick mass occurred during a period of warming in the Barents Sea such that future recruitment into the population will depend partly on the long-term changes in ocean climate in the region.     

Knowledge creation and reliable decision-making in complex emergencies

This paper examines how the creation of knowledge and the location of decision-making authority within relief organisations influence coordination. Information was collected from the headquarters of international non-governmental organisations in 2003, as well as from Darfur and Khartoum, Sudan, in 2005 and 2007, respectively. Relief organisations rely on quality information dissemination between the field and headquarters. Yet, reporting from the field often is overloaded with misplaced precision, making it difficult for managers at headquarters to grasp the key issues. A high turnover rate among international field officers and a lack of inclusion of local staff and partners prevent the development of accumulated knowledge. Furthermore, most relief organisations have a centralised decision-making system. The creation of 'collective-meaning structures', based on reliable information on all decision-making levels, opens the way to the decentralisation of decision-making to field officers engaged with inter-organisational coordination structures. In sum, more efficient and reliable coordination between organisations relies on improved decision-making systems within each organisation.     

Perfluorinated and chlorinated pollutants as predictors of demographic parameters in an endangered seabird

Despite global occurrence of several perfluorinated compounds (PFCs) the potential ecological effects of such substances on natural populations are not known. In endangered lesser black-backed gulls (Larus fuscus fuscus) on the Norwegian Coast, the blood concentrations of PFCs were as high as legacy organochlorines (OCs), and here we examined whether PFCs show associations similar to those of OCs to factors potentially affecting population growth, by evaluating relationships between contaminant concentrations and demographic parameters (reproductive performance and the probability of adults returning between breeding seasons). PFCs were not adversely associated with demographic parameters, while the most persistent OCs; notably PCB and p,p′-DDE, were adversely associated with early chick survival, and adult return rate. This study thus suggests that when the concentrations of PFCs and OCs are of similar magnitude in a gull population, OCs are more likely to cause adverse ecological effects.     

Cost-effective unilateral climate policy design: Size matters

Given the bleak prospects for a global agreement on mitigating climate change, pressure for unilateral abatement is increasing. A major challenge is emissions leakage. Border carbon adjustments and output-based allocation of emissions allowances can increase effectiveness of unilateral action but introduce distortions of their own. We assess antileakage measures as a function of abatement coalition size. We first develop a partial equilibrium analytical framework to see how these instruments affect emissions within and outside the coalition. We then employ a computable general equilibrium model of international trade and energy use to assess the strategies as the coalition grows. We find that full border adjustments rank first in global cost-effectiveness, followed by import tariffs and output-based rebates. The differences across measures and their overall appeal decline as the abatement coalition grows. In terms of cost, the coalition countries prefer border carbon adjustments; countries outside the coalition prefer output-based rebates.     

Sex ratio in lesser black-backed gull in relation to environmental pollutants

In birds, there is ample evidence that the mother can manipulate the sex of the young and produce more of the sex, which gives the highest fitness return. This has previously been documented in gulls, Laridae. Gulls are sexually size dimorphic with males larger than females, and there is good evidence that parents in poor body condition switch their investment to the smallest sex. In the present study, we examined the primary sex ratio and the survival of male and female chicks of lesser black-backed gull (Larus fuscus fuscus) in relation to their blood levels of organochlorines (OCs), perfluorinated compounds (PFCs) and polybrominated diphenyl ethers (BDE-47). We show that females with high levels of OCs (but not PFCs and BDE-47) are likely to skew their sex ratio at hatching towards female offspring. Few females had very high levels of OCs, and the many females with low levels of OCs overproduced sons resulting in a male skew at hatching (59%). The survival of female offspring was lower than the survival of male offspring, causing an even stronger male skew in sex ratio (71%). There is evidence to conclude that circulating levels of OCs in the blood of females may have detrimental effect on the sex allocation strategy and could be of serious threat to the population. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Relationships between reproductive performance and organochlorine contaminants in great black-backed gulls (Larus marinus)

The great black-backed gull Larus marinus is a top predator in subarctic and temperate marine ecosystems, and the aim of this study was to investigate if organochlorines (OCs) were related to reproductive performance in this species at the subarctic parts of the Norwegian Coast. We measured blood levels of various OCs in 53 breeding birds. The OC levels were relatively low compared to levels found in nearby arctic areas. In females, however, there was a significant positive relationship between blood concentrations of OCs, especially hexachlorobenzene (HCB) and, p,p'-dichlorodiphenyldichloroethylene (DDE), and egg laying date, and a positive relationship between the probability of nest predation and blood concentration of beta-hexachlorocyclohexane (beta-HCH), oxychlordane, and DDE. In females with high levels of OCs, especially persistent polychlorinated biphenyls (PCBs), there was also a decline in egg volume as egg laying progressed; i.e. the second and third laid egg were relatively smaller, compared to females with low OC levels. No relationships between reproductive parameters and OC levels were found in males.     

Relationships between ecological variables and four organochlorine pollutants in an artic glaucous gull (Larus hyperboreus) population

The Arctic has become a sink for organochlorine contaminants (OCs) from lower latitudes, and relatively high levels have been found in different biota. Recent studies of the glaucous gull, Larus hyperboreus, a top predator in the arctic food web, have documented that high blood residues of various OCs are related to lower reproductive performance and reduced adult survival. Here we provide additional evidence that OCs are having ecological effects in the glaucous gull population at Bear Island in the Norwegian Arctic, and compare the effects of the four major OCs found in the glaucous gulls: HCB, oxychlordane, DDE and PCBs, which made up >95% of measured OCs. Firstly; it has previously been shown that gulls with high levels of PCBs in their blood spent more time away from the nest site during incubation than gulls with low levels. Here we reanalyzed the data and found that PCBs (P<0.02) and oxychlordane (P<0.05) were positive and significantly related to time away from the nest site, while DDE and HCB were not related to this trait. Secondly, among females which bred in an area where fish dominated the diet, and thus had high flight costs during feeding, early chick growth was negatively related to maternal levels of all four OCs, especially HCB and DDE (P<0.01). On the contrary, among females breeding in an area where the diet was dominated by eggs and young from nearby seabird colonies, and thus feeding costs were low, there were no effects of OC levels on early chick growth. This indicates that additional stress may be fundamental in causing reproductive effects of OCs in this population. Finally, during three breeding seasons we examined the probability of adults returning to the breeding grounds in the subsequent season, as a function of blood concentration of the four OCs. Overall, return rate from one year to the next was negatively related to blood residues of oxychlordane (P=0.02), but not significantly related to the other three compounds. Further support for the importance of oxychlordane was that a 60% drop in the blood levels between 1997 and 2000 led to a significant increase in return rate between these two years.