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Unpublished accounts indicate that the number of Tufted Puffin Fratercula cirrhata colonies in western Canada has declined in recent decades. However, a lack of recent colony count data makes it impossible to determine current trends. Here we compile published and unpublished information for Tufted Puffins in the Canadian portion of the California Current System (i.e., from the vicinity of the Scott Islands south to the Canada-US border) to update understanding of the species' status in the region, and to assemble available information in a single source. We found historical records of three additional colonies over those in pre-existing compilations, bringing the total count for the region to 19. However, 11 of these are currently extirpated and another three likely so. All but one of these extirpated colonies are 'very small' (historical mode of counts, 1-3 pairs), reflecting patterns of Tufted Puffin colony loss in US waters to the south. Two larger puffin colonies (historical counts, 20-50 pairs) underwent abandonment in the 1990s, but one of these appears to have been recolonized recently. Tufted Puffin numbers at Canada's largest colony, Triangle Island, are likely stable. A lack of standardized monitoring of these colonies, with the exception of Triangle Island, makes it challenging to understand population trends, undertake restoration work, or mitigate current threats. [ABSTRACT FROM AUTHOR]

We conducted a multi-year (1999-2001) radio telemetry study to determine patterns of colony attendance among breeding Cassin's Auklets Ptychoramphus aleuticus during the chick-rearing period on Triangle Island in British Columbia, Canada. A total of 1 625 detections were obtained for 80 individual birds (24-28 birds per year), each detected 20.3 times on average. We found that colony attendance (arrival times, departure times, in-burrow shift duration) and foraging trip duration (i.e., time away from the colony) were remarkably synchronous among individuals and years. On average, birds arrived in a pulse after darkness, with 67% of returns between 23h15 and 00h15 and a peak (22% of all returns) between 23h30 and 23h45. Birds departed synchronously en masse before sunrise, with 86% of departures between 03h15 and 04h15 and a peak (38% of all departures) between 03h45 and 04h00. Overall, parents visited the colony every 19.8 hours (median) and stayed for roughly four hours during the chick-rearing period. At the beginning of the season, female foraging trip duration was longer than that of males, though this decreased with day of year, suggesting that females may aim to recover condition immediately following egg production via increased foraging time. Most breeders routinely visited the colony every night despite the risk posed by avian predators. Understanding patterns of colony attendance is important, given changing ocean conditions and prey availability in the vicinity of the world's largest colony for this species. [ABSTRACT FROM AUTHOR]

We review the precautionary approach to fisheries management, propose a framework that will allow a systematic assessment of insufficient precaution and provide an illustration using an Antarctic fishery. For a single-species fishery, our framework includes five attributes: (1) limit reference points that recognize gaps in our understanding of the dynamics of the species; (2) accurate measures of population size; (3) ability to detect population changes quickly enough to arrest unwanted declines; (4) adequate understanding of ecosystem dynamics to avoid adverse indirect effects; and (5) assessment of the first four elements by a sufficiently impartial group of scientists. We argue that one or more of these elements frequently fail to be present in the management of many fisheries. Structural uncertainties, which characterize almost all fisheries models, call for higher limit points than those commonly used. A detailed look into the five elements and associated uncertainties is presented for the fishery on the Antarctic toothfish in the Ross Sea ( FAO/ CCAMLR Area 88.1, 88.2), for which management was recently described as 'highly precautionary'. In spite of having features that make the Ross Sea fishery ideal for the application of the precautionary approach, gaps in our knowledge and failure to acknowledge these gaps mean that current regulation falls short of being sufficiently precautionary. We propose some possible remedies. [ABSTRACT FROM AUTHOR]

Measurements of naturally occurring stable isotopes in tissues of seabirds and their prey are a powerful tool for investigating long-term changes in marine foodwebs. Recent isotopic (δ15N, δ13C) evidence from feathers of Glaucous-winged Gulls (Larus glaucescens) has shown that over the last 150 years, this species shifted from a midtrophic marine diet to one including lower trophic marine prey and/or more terrestrial or freshwater foods. However, long-term isotopic patterns of δ15N and δ13C cannot distinguish between the relative importance of lower trophic-level marine foods and terrestrial sources. We examined 48 feather stable-hydrogen (δ²H) and -sulfur (δ34S) isotope values from this same 150-year feather set and found additional isotopic evidence supporting the hypothesis that gulls shifted to terrestrial and/or freshwater prey. Mean feather δ²H and δ34S values (±SD) declined from the earliest period (1860-1915; n = 12) from −2.5 ± 21.4‰ and 18.9 ± 2.7 ‰, respectively, to −35.5 ± 15.5 ‰ and 14.8 ± 2.4 ‰, respectively, for the period 1980-2009 (n = 12). We estimated a shift of ~30% increase in dependence on terrestrial/freshwater sources. These results are consistent with the hypothesis that gulls increased terrestrial food inputs in response to declining forage fish availability. [ABSTRACT FROM AUTHOR]

The world's oceans have undergone significant ecological changes following European colonial expansion and associated industrialization. Seabirds are useful indicators of marine food web structure and can be used to track multidecadal environmental change, potentially reflecting long-term human impacts. We used stable isotope ( δ13C, δ15N) analysis of feathers from glaucous-winged gulls ( Larus glaucescens) in a heavily disturbed region of the northeast Pacific to ask whether diets of this generalist forager changed in response to shifts in food availability over 150 years, and whether any detected change might explain long-term trends in gull abundance. Sampled feathers came from birds collected between 1860 and 2009 at nesting colonies in the Salish Sea, a transboundary marine system adjacent to Washington, USA and British Columbia, Canada. To determine whether temporal trends in stable isotope ratios might simply reflect changes to baseline environmental values, we also analysed muscle tissue from forage fishes collected in the same region over a multidecadal timeframe. Values of δ13C and δ15N declined since 1860 in both subadult and adult gulls ( δ13C, ~ 2-6‰; δ15N, ~4-5‰), indicating that their diet has become less marine over time, and that birds now feed at a lower trophic level than previously. Conversely, forage fish δ13C and δ15N values showed no trends, supporting our conclusion that gull feather values were indicative of declines in marine food availability rather than of baseline environmental change. Gradual declines in feather isotope values are consistent with trends predicted had gulls consumed less fish over time, but were equivocal with respect to whether gulls had switched to a more garbage-based diet, or one comprising marine invertebrates. Nevertheless, our results suggest a long-term decrease in diet quality linked to declining fish abundance or other anthropogenic influences, and may help to explain regional population declines in this species and other piscivores. [ABSTRACT FROM AUTHOR]