Discontinuous change in ice cover in Hudson Bay in the 1990s and some consequences for marine birds and their prey

PUBLISHED | 2012 in Ices Journal of Marine Science [IF: 2.76]
Marine Ecosystems and Global Change
The ocean is a vital component of the metabolism of the Earth and plays a key role in global change. In fact, the oceans cover so much of the Earth's surface that our planet has been described as the Water Planet, and it could be argued that its most extensive ecosystems are marine. Marine ecosystems are inextricably involved in the physical, chemical, biological and societal processes of global change. It is impossible to describe and understand the Earth system without understanding the ocean,...
Atmospheric forcing of sea ice in Hudson Bay during the fall period, 1980-2005
[1] The principal objective of this study is to describe the autumn sea ice regime of Hudson Bay in the context of atmospheric forcing from 1980 to 2005. Both gridded Canadian Ice Service (CIS) data and Passive Microwave (PMW) data are used to examine the freezeup period for weeks of year (WOY) 43–52. Sea ice concentration (SIC) anomalies reveal statistically significant trends, ranging from −23.3% to −26.9% per decade, during WOY 43–48 using the CIS data and trends ranging from −12.7% to −16.8%...
Tropical Atlantic sea surface temperature variability and its relation to El Niño-Southern Oscillation
Past analyses of tropical Atlantic sea surface temperature variability have suggested a dipole behavior between the northern and southern tropics, across the Intertropical Convergence Zone (ITCZ). By analyzing an improved 43-year (1950-1992) record of SST (Smith et al., 1996) and other data derived from the Comprehensive Ocean-Atmosphere Data Set (COADS), it is shown that the regions north and south of the ITCZ are statistically independent of each other at the seasonal to interannual timescales...
Movements and wintering areas of breeding age Thick-billed Murre Uria lomvia from two colonies in Nunavut, Canada
PUBLISHED | 2011 in Marine Biology [IF: 2.14]
The non-breeding movements of marine birds were poorly known until recently, but this information is essential to understanding the risk to different geographical populations from events on the wintering grounds. We tracked the migration routes and wintering areas of Thick-billed Murre Uria lomvia from two breeding colonies in eastern Canada: Coats Island in northern Hudson Bay and The Minarets, Baffin Island, during the period August 2007–May 2008 using geolocation loggers. Birds from The Minar...
Antarctic sea ice variability and trends, 1979–2010
PUBLISHED | 2012 in The Cryosphere
Analyses of 32 yr (1979–2010) of Arctic sea ice extents and areas derived from satellite passive microwave radiometers are presented for the Northern Hemisphere as a whole and for nine Arctic regions. There is an overall negative yearly trend of −51.5 ± 4.1 × 10 3 km 2 yr −1 (−4.1 ± 0.3% decade −1 ) in sea ice extent for the hemisphere. The yearly sea ice extent trends for the individual Arctic regions are all negative except for the Bering Sea: −3.9 ± 1.1 × 10 3 km 2 yr −1 (−8.7 ± 2.5% decade −...
Atmospheric forcing of sea ice in Hudson Bay during the spring period, 1980–2005
PUBLISHED | 2011 in Journal of Marine Systems [IF: 2.44]
Abstract In this study we show recent trends in sea ice concentration (SIC) and sea ice extent (SIE) in Hudson Bay (HB) using Canadian Ice Service (CIS) data and passive microwave (PMW) data for the spring period, week of year (WOY) 24–30. Reductions in sea ice concentration and sea ice extent are examined in light of thermodynamic and dynamic forcing of sea ice. Results show surface air temperature (SAT) anomalies surrounding Hudson Bay have been increasing by 0.26 to 0.30 °C/decade from 1960 t...
The diet of Thick-billed Murres (Uria lomvia) in west Hudson Strait and northeast Hudson Bay
PUBLISHED | 1985 in Canadian Journal of Zoology [IF: 1.35]
We collected feeding adult Thick-billed Murres at several different localities within the foraging range of the colonies at Digges Sound through the breeding seasons in 1980, 1981, and 1982. Examination of prey remains from the stomach and foregut showed that the majority of birds contained prey covering a range of sizes from 0.01 to 47 g wet weight at ingestion. The total energy equivalent of prey found in the majority of stomachs was less than 10% of the birds' probable daily requirements. Com...
Cited by27
Seabird diet changes in northern Hudson Bay, 1981-2013, reflect the availability of schooling prey
PUBLISHED | 2014 in Marine Ecology Progress Series [IF: 2.29]
Ongoing climate change is altering Arctic marine ecosystems with major conse- quences for food-webs. Seabirds, by foraging over large marine areas but returning regularly to their breeding colonies, provide a good medium for tracking such changes. We studied the prey delivered to nestling thick-billed murres Uria lomvia at a colony in northern Hudson Bay, Canada, over the period 1981−2013. During that period, ice conditions in the region altered substantially, with earlier break-up and clearance...
Ice bridging as a dispersal mechanism for Arctic terrestrial vertebrates and the possible consequences of reduced sea ice cover
PUBLISHED | 2012 in Biodiversity
The dispersal abilities of terrestrial mammals are severely constrained by water crossings, resulting in islands generally supporting less diverse mammal faunas than similar continental areas. In ice-affected Arctic regions, seasonal or permanent ice cover provides a bridging mechanism for dispersal, allowing water gaps to be crossed more rapidly and with less energy cost than is entailed in swimming. Consequently, islands that might be out of reach if waters were open become much more readily c...
The influence of weather and lemmings on spatiotemporal variation in the abundance of multiple avian guilds in the arctic.
PUBLISHED | 2014 in PLOS ONE [IF: 2.81]
Climate change is occurring more rapidly in the Arctic than other places in the world, which is likely to alter the distribution and abundance of migratory birds breeding there. A warming climate can provide benefits to birds by decreasing spring snow cover, but increases in the frequency of summer rainstorms, another product of climate change, may reduce foraging opportunities for insectivorous birds. Cyclic lemming populations in the Arctic also influence bird abundance because Arctic foxes be...
Changes in Food Web Structure Alter Trends of Mercury Uptake at Two Seabird Colonies in the Canadian Arctic
PUBLISHED | 2014 in Environmental Science & Technology [IF: 6.20]
Arctic ecosystems are changing in response to climate change and some Arctic food web structures are being affected in ways which may have potential consequences for the biomagnification of environmental contaminants. Here, we examined how a shift in diet of an Arctic seabird resulted in a change of trophic position and how that change affected exposure to mercury over time. The thick-billed murre (Uria lomvia), which breeds in the eastern Canadian Arctic, has been monitored for diet and environ...
Arctic Sea Ice in Transformation: A Review of Recent Observed Changes and Impacts on Biology and Human Activity
PUBLISHED | 2014 in Reviews of Geophysics [IF: 12.34]
Sea ice in the Arctic is one of the most rapidly changing components of the global climate system. Over the past few decades, summer areal extent has declined over 30%, and all months show statistically significant declining trends. New satellite missions and techniques have greatly expanded information on sea ice thickness, but many uncertainties remain in the satellite data and long-term records are sparse. However, thickness observations and other satellite-derived data indicate a 40% decline...
Could the planktonic stages of polar cod and Pacific sand lance compete for food in the warming Beaufort Sea
PUBLISHED | 2014 in Ices Journal of Marine Science [IF: 2.76]
The boreal Pacific sand lance (Ammodytes hexapterus) was recently detected in southeastern Beaufort Sea (Canadian Arctic), numbering as the second most abundant ichthyoplankton species after the polar cod (Boreogadus saida) in 2011. We contrast the hatching periods, growth, prey selectivity, and feeding success of the planktonic stages of the two species. Polar cod hatched from January to mid-July and sand lance from mid-July to early September, precluding any competition among the larval stages...
The broad footprint of climate change from genes to biomes to people
PUBLISHED | 2016 in Science [IF: 37.20]
Most ecological processes now show responses to anthropogenic climate change. In terrestrial, freshwater, and marine ecosystems, species are changing genetically, physiologically, morphologically, and phenologically and are shifting their distributions, which affects food webs and results in new interactions. Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varie...
Demography of an apex predator at the edge of its range: impacts of changing sea ice on polar bears in Hudson Bay.
PUBLISHED | 2016 in Ecological Applications [IF: 4.31]
Changes in the abundance and distribution of wildlife populations are common consequences of historic and contemporary climate change. Some Arctic marine mammals, such as the polar bear (Ursus maritimus), may be particularly vulnerable to such changes due to the loss of Arctic sea ice. We evaluated the impacts of environmental variation on demographic rates for the Western Hudson Bay (WH), polar bear subpopulation from 1984 to 2011 using live-recapture and dead-recovery data in a Bayesian implem...
Composition and temporal variation in the diet of beluga whales, derived from stable isotopes
PUBLISHED | 2012 in Marine Ecology Progress Series [IF: 2.29]
The diet of individuals within a species commonly differs among sex and age classes because of differences in energy requirements and physiological needs. Belugas Delphinapterus leucas show a high level of sexual habitat segregation and dimorphism that could result in differ- ences in diet between the sexes. Here, we used stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) from muscle and skin samples of 88 belugas, and likely prey species, to investigate how beluga diet in Cumberland Sound...