The huge quantities of waste produced by commercial fisheries worldwide attract large numbers of scavengers. Reducing this wasteful practice is desirable, but may have implications for marine ecosystems as scavengers will face a major shortfall in food. Predicting the impact of reduced discarding requires information on the strength of the link between scavengers and fisheries. We analysed sagittal otoliths regurgitated by great skuas Stercorarius skua over 5 yr from 8 different colonies in Shetland, UK, and over 18 yr from 1 of these sites, in relation to spatial and temporal variation in fisheries activity. The proportions of 2 demersal fish not normally available to skuas, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus, are positively correlated with annual variation in discard estimates. The proportion of whiting at 8 colonies is positively correlated with spatial differences in fish biomass estimates, and blue whiting Micromesistus potassou are only eaten in colonies close to the continental shelf edge, where this species is fished. Non-breeding great skuas tend to eat smaller and significantly more variable discarded fish compared with breeders. Our results indicate that great skuas rely heavily on fishery discards and are also sensitive to spatial and temporal changes in fisheries activity. Differences between breeding status indicate that the nonbreeding component of the population may respond differently to changing discard policy. The strength of the link between fisheries and scavengers appear to be species-specific, and testing the strength of these relationships should be an important avenue of future research to interpret the response of scavengers to changes in fisheries management.KEY WORDS: Fisheries · Discards · Seabirds · Diet · Scavenger · Foraging Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 367: [223][224][225][226][227][228][229][230][231][232] 2008 ability has also been shown to directly influence aspects of seabird breeding (Oro et al. 1996), overwinter condition (Hüppop & Wurm 2000) and demography (Oro & Pradel 2000). Global-scale declines in discard availability may leave artificially inflated populations of scavenging seabirds short of food, which has profound implications for aquatic food web dynamics, as well as conservation and ecosystem management (Regehr & Montevecchi 1997, Stenhouse & Montevecchi 1999, Votier et al. 2004a. Thus, it is imperative that we gain a better understanding of the impact of changes in discarding rates for seabird communities.Regardless of the evidence that seabirds scavenge extensively for discards, our grasp of the ways in which they interact with fisheries is still limited. For instance, despite the evidence that fisheries closure or moratoria can have an impact on aspects of seabird ecology (Oro et al. 1996, Hüppop & Wurm 2000, other studies indicate that natural foods may be more important than discards to scavenging species. Although northern gannets Morus bassanus sho...

The Black Death is the most reknown pandemic in human history, believed by many to have killed half of Europe's population. However, despite the advances in ancient DNA research that allowed for the successful identification of the pandemic's causative agent (bacterium Yersinia pestis), our knowledge of the Black Death is still limited, based primarily on medieval texts available for single areas of Western Europe. In our study we remedy this situation and we focus in particular on the scale of the Black Death mortality. We collected data on landscape change from 261 coring sites (lakes and wetlands) located in 19 European countries. We used two independent methods of analysis to evaluate whether the changes we see in the landscape at the time of the Black Death agree with the hypothesis that half of the population died within a single year in each of the 21 regions we studied. We discovered that while the Black Death had devastating impact in some regions, it had negligible or no impact in others. The inter-regional differences in the Black Death mortality across Europe demonstrate the significance of cultural, ecological, economic and climatic factors that mediate the dissemination and impact of the disease. The complex interplay of these factors, along with the identification of the pathogen that caused disease outbreaks, should be the focus of future research on historical pandemics.

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