A new method for chemical fingerprinting of petroleum biomakers is described. The method consists of GC-MS analysis, preprocessing of GC-MS chromatograms, and principal component analysis (PCA) of selected regions. The preprocessing consists of baseline removal by derivatization, normalization, and alignment using correlation optimized warping. The method was applied to chromatograms of m/z 217 (tricyclic and tetracyclic steranes) of oil spill samples and source oils. Oil spill samples collected from the coastal environment in the weeks after the Baltic Carrier oil spill were clustered in principal components 1 to 4 with oil samples from the tank of the Baltic Carrier (source oil). The discriminative power of PCA was enhanced by deselecting the most uncertain variables or scaling them according to their uncertainty, using a weighted least squares criterion. The four principal components were interpreted as follows: boiling point range (PC1), clay content (PC2), carbon number distribution of sterols in the source rock (PC3), and thermal maturity of the oil (PC4). In summary, the method allows for analyses of chromatograms using a fast and objective procedure and with more comprehensive data usage compared to other fingerprinting methods.

Using grizzly bears as surrogates for “salmon ecosystem” function, the authors develop a generalizable ecosystem-based management framework that enables decision-makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish.

Understanding cumulative effects of multiple threats is key to guiding effective management to conserve endangered species. The critically endangered, Southern Resident killer whale population of the northeastern Pacific Ocean provides a data-rich case to explore anthropogenic threats on population viability. Primary threats include: limitation of preferred prey, Chinook salmon; anthropogenic noise and disturbance, which reduce foraging efficiency; and high levels of stored contaminants, including PCBs. We constructed a population viability analysis to explore possible demographic trajectories and the relative importance of anthropogenic stressors. The population is fragile, with no growth projected under current conditions, and decline expected if new or increased threats are imposed. Improvements in fecundity and calf survival are needed to reach a conservation objective of 2.3% annual population growth. Prey limitation is the most important factor affecting population growth. However, to meet recovery targets through prey management alone, Chinook abundance would have to be sustained near the highest levels since the 1970s. The most optimistic mitigation of noise and contaminants would make the difference between a declining and increasing population, but would be insufficient to reach recovery targets. Reducing acoustic disturbance by 50% combined with increasing Chinook by 15% would allow the population to reach 2.3% growth.

Canada's Policy for Conservation of Wild Pacific Salmon has been heralded as a transformative approach to the management of wild salmon whereby conservation is the highest priority. Given that changes to the Policy are under consideration, it is timely that we understand whether our state of knowledge and the status of wild salmon in Canada have indeed improved after its adoption in 2005. To answer these questions, we used two indices of improvement: (i) monitoring effort and (ii) abundance of spawning adults. Our results, based on data for all species from British Columbia's north and central coasts, show that monitoring effort has continued to erode, abundance of spawning adults has significantly declined for several species, the status of many salmon Conservation Units are in zones of concern, and 42% of the Conservation Units that we assessed as Red (threatened) would have improved in status had the Canadian fishery been reduced. We conclude with recommendations to help improve our knowledge of the status of salmon and enable a robust and successfully implemented Wild Salmon Policy for the future.Résumé : La Politique du Canada pour la conservation du saumon sauvage du Pacifique a été annoncée comme constituant une tranformation dans l'approche de gestion du saumon sauvage axée prioritairement sur la conservation. Comme la modification de la politique est actuellement à l'étude, il est opportun de se demander si l'état des connaissances et le statut des saumons sauvages au Canada se sont effectivement améliorés après l'adoption de la Politique en 2005. Pour répondre à ces questions, nous utilisons les deux indices d'amélioration suivants : (i) l'effort de surveillance et (ii) l'abondance des adultes géniteurs. Nos résultats, qui reposent sur des données pour toutes les espèces le long du littoral nord et central de la Colombie-Britannique, montrent que l'effort de surveillance continue de s'éroder, que l'abondance des adultes géniteurs a diminué de manière significative pour plusieurs espèces, que le statut de nombreuses Unités de conservation du saumon est préoccupant et que le statut de 42 % des Unités de conservation que nous avons évalué comme étant rouge (mauvais état) se serait amélioré si la pêche canadienne avait été réduite. Nous concluons en formulant des recommandations pour aider à améliorer les connaissances sur l'état du saumon et permettre la mise en oeuvre efficace d'une politique sur le saumon sauvage à l'avenir. [Traduit par la Rédaction]