Timing of spring sea-ice retreat shapes the southeast Bering Sea food web. We compared summer sea... more Timing of spring sea-ice retreat shapes the southeast Bering Sea food web. We compared summer seabird densities and average bathymetry depth-distributions between years with early (typically warm) and late (typically cold) ice-retreat. Averaged over all seabird species, densities in early-ice-retreat-years were 10.1% (95%CI: 1.1–47.9%) of that in late-ice-retreat-years. In early-ice-retreat-years, surface-foraging species had increased numbers over the middle shelf (50–150 m) and reduced numbers over the shelf slope (200–500 m). Pursuit-diving seabirds showed a less clear trend. Euphausiids and the copepod <i>Calanus marshallae/glacialis</i> were 2.4 and 18.1 times less abundant in early-ice-retreat-years, respectively, whereas age-0 walleye pollock <i>Gadus chalcogrammus</i> near-surface densities were 51× higher in early-ice-retreat-years. Our results suggest a mechanistic understanding of how present and future changes in sea-ice-retreat timing may affect top predators like seabirds in the southeastern Bering Sea.
this document. Eventually, the document will contain a more complete set of indicators and an eva... more this document. Eventually, the document will contain a more complete set of indicators and an evaluation of the meaning of the observed changes. For example, the habitat section is presently missing information on time series trends of fishing effort by non-trawl gear types and more information from NMFS trawl surveys could be used to provide information on population trends of non-target species. Also missing is status and trend information for other managed resources such as crab, herring, and salmon. Future evaluations will provide an assessment of whether the observed change was beneficial, detrimental, or neutral with respect to a particular ecosystem issue
... These re-sults suggest that at sea surveys in late summer provide a reasonable index of local... more ... These re-sults suggest that at sea surveys in late summer provide a reasonable index of local productivity for nearshore alcids. Further ... Because of the murrelet&amp;#x27;s threatened status from British Columbia to California (Ralph et al. 1995 ...
ABSTRACT Extreme reductions in sea ice extent and thickness in the Pacific Arctic Region (PAR) ha... more ABSTRACT Extreme reductions in sea ice extent and thickness in the Pacific Arctic Region (PAR) have become a hallmark of climate change over the past decade, but their impact on the marine ecosystem is poorly understood. As top predators, marine fishes, birds and mammals (collectively, upper trophic level species, or UTL) must adapt via biological responses to physical forcing and thereby become sentinels to ecosystem variability and reorganization. Although there have been no coordinated long-term studies of UTL species in the PAR, we provide a compilation of information for each taxa as an ecological foundation from which future investigations can benefit. Subsequently, we suggest a novel UTL-focused research framework focused on measurable responses of UTL species to environmental variability as one way to ascertain shifts in the PAR marine ecosystem. In the PAR, indigenous people rely on UTL species for subsistence and cultural foundation. As such, marine fishes, birds and mammals represent a fundamental link to local communities while simultaneously providing a nexus for science, policy, education and outreach for people living within and outside the PAR.
... Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columb... more ... Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia. Authors: JF Piatt; KJ Kuletz; AE Burger; SA Hatch; VL Friesen; TP Birt; ML Arimitsu; GS Drew; AM Harding; KS Bixler; GEOLOGICAL SURVEY RESTON VA. ...
... Michelle Kissling1,3, Kathy Kuletz2, and Steve Brockmann1 ... For all shoreline and offshore ... more ... Michelle Kissling1,3, Kathy Kuletz2, and Steve Brockmann1 ... For all shoreline and offshore transects in protected bays or under calm sea conditions, we used 5.5 m hard-hulled skiffs with two observers and boat operator, and transect width was 100 m either side of and ahead of ...
Abstract We assessed the biogeography of seabirds within the Bering Sea Large Marine Ecosystem (L... more Abstract We assessed the biogeography of seabirds within the Bering Sea Large Marine Ecosystem (LME), a highly productive and extensive continental shelf system that supports important fishing grounds. Our objective was to investigate how physical ocean conditions impact distribution of seabirds along latitudinal gradients. We tested the hypothesis that seabird biogeographic patterns reflect differences in ocean conditions relating to the boundary between northern and southern shelf ecosystems. We used a grid-based approach to develop spatial means (1975–2014) of summertime seabird species' abundance, species' richness, and a multivariate seabird assemblage index to examine species composition. Seabird indices were linked to ocean conditions derived from a data-assimilative oceanographic model to quantify relationships between physics (e.g., temperature, salinity, and current velocity), bathymetry and seabirds along latitudinal gradients. Species assemblages reflected two main sources of variation, a mode for elevated richness and abundance, and a mode related to partitioning of inner/middle shelf species from outer shelf-slope species. Overall, species richness and abundance increased markedly at higher latitudes. We found that latitudinal changes in species assemblages, richness and abundance indicates a major shift around 59–60°N within inner and middle shelf regions, but not in the outer shelf. Within the middle shelf, latitudinal shifts in seabird assemblages strongly related to hydrographic structure, as opposed to the inner and outer shelf waters. As expected, elevated species richness and abundance was associated with major breeding colonies and within important coastal foraging areas. Our study also indicates that seabird observations supported the conclusion that the oceanographic model captured mesoscale variability of ocean conditions important for understanding seabird distributions and represents an important step for evaluating modeling and empirical studies. Biogeographic assessments of LMEs that integrate top predator distributions resolve critical habitat requirements and will benefit assessment of climate change impacts (e.g., sea-ice loss) predicted to affect high-latitude marine ecosystems.
KL Oakley, KJ Kuletz American Fisheries Society Symposium. 1996., 1996. ... The postspill populat... more KL Oakley, KJ Kuletz American Fisheries Society Symposium. 1996., 1996. ... The postspill population was 43% smaller than the prespill population, but we could not attribute the entire decline to the spill because a decline in this guillemot population may have predated the spill. ...
Studies of the impacts of climate change on Arctic marine ecosystems have largely centered on end... more Studies of the impacts of climate change on Arctic marine ecosystems have largely centered on endemic species and ecosystems, and the people who rely on them. Fewer studies have focused on the northward expansion of upper trophic level (UTL) subarctic species. We provide an overview of changes in the temporal and spatial distributions of subarctic fish, birds, and cetaceans, with a focus on the Pacific Arctic Region. Increasing water temperatures throughout the Arctic have increased “thermal habitat” for subarctic fish species, resulting in northward shifts of species including walleye pollock and pink salmon. Ecosystem changes are altering the community composition and species richness of seabirds in the Arctic, as water temperatures change the available prey field, which dictates the presence of planktivorous versus piscivorous seabird species. Finally, subarctic whales, among them killer and humpback whales, are arriving earlier, staying later, and moving consistently farther nor...
Timing of spring sea-ice retreat shapes the southeast Bering Sea food web. We compared summer sea... more Timing of spring sea-ice retreat shapes the southeast Bering Sea food web. We compared summer seabird densities and average bathymetry depth-distributions between years with early (typically warm) and late (typically cold) ice-retreat. Averaged over all seabird species, densities in early-ice-retreat-years were 10.1% (95%CI: 1.1–47.9%) of that in late-ice-retreat-years. In early-ice-retreat-years, surface-foraging species had increased numbers over the middle shelf (50–150 m) and reduced numbers over the shelf slope (200–500 m). Pursuit-diving seabirds showed a less clear trend. Euphausiids and the copepod <i>Calanus marshallae/glacialis</i> were 2.4 and 18.1 times less abundant in early-ice-retreat-years, respectively, whereas age-0 walleye pollock <i>Gadus chalcogrammus</i> near-surface densities were 51× higher in early-ice-retreat-years. Our results suggest a mechanistic understanding of how present and future changes in sea-ice-retreat timing may affect top predators like seabirds in the southeastern Bering Sea.
this document. Eventually, the document will contain a more complete set of indicators and an eva... more this document. Eventually, the document will contain a more complete set of indicators and an evaluation of the meaning of the observed changes. For example, the habitat section is presently missing information on time series trends of fishing effort by non-trawl gear types and more information from NMFS trawl surveys could be used to provide information on population trends of non-target species. Also missing is status and trend information for other managed resources such as crab, herring, and salmon. Future evaluations will provide an assessment of whether the observed change was beneficial, detrimental, or neutral with respect to a particular ecosystem issue
... These re-sults suggest that at sea surveys in late summer provide a reasonable index of local... more ... These re-sults suggest that at sea surveys in late summer provide a reasonable index of local productivity for nearshore alcids. Further ... Because of the murrelet&amp;#x27;s threatened status from British Columbia to California (Ralph et al. 1995 ...
ABSTRACT Extreme reductions in sea ice extent and thickness in the Pacific Arctic Region (PAR) ha... more ABSTRACT Extreme reductions in sea ice extent and thickness in the Pacific Arctic Region (PAR) have become a hallmark of climate change over the past decade, but their impact on the marine ecosystem is poorly understood. As top predators, marine fishes, birds and mammals (collectively, upper trophic level species, or UTL) must adapt via biological responses to physical forcing and thereby become sentinels to ecosystem variability and reorganization. Although there have been no coordinated long-term studies of UTL species in the PAR, we provide a compilation of information for each taxa as an ecological foundation from which future investigations can benefit. Subsequently, we suggest a novel UTL-focused research framework focused on measurable responses of UTL species to environmental variability as one way to ascertain shifts in the PAR marine ecosystem. In the PAR, indigenous people rely on UTL species for subsistence and cultural foundation. As such, marine fishes, birds and mammals represent a fundamental link to local communities while simultaneously providing a nexus for science, policy, education and outreach for people living within and outside the PAR.
... Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columb... more ... Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia. Authors: JF Piatt; KJ Kuletz; AE Burger; SA Hatch; VL Friesen; TP Birt; ML Arimitsu; GS Drew; AM Harding; KS Bixler; GEOLOGICAL SURVEY RESTON VA. ...
... Michelle Kissling1,3, Kathy Kuletz2, and Steve Brockmann1 ... For all shoreline and offshore ... more ... Michelle Kissling1,3, Kathy Kuletz2, and Steve Brockmann1 ... For all shoreline and offshore transects in protected bays or under calm sea conditions, we used 5.5 m hard-hulled skiffs with two observers and boat operator, and transect width was 100 m either side of and ahead of ...
Abstract We assessed the biogeography of seabirds within the Bering Sea Large Marine Ecosystem (L... more Abstract We assessed the biogeography of seabirds within the Bering Sea Large Marine Ecosystem (LME), a highly productive and extensive continental shelf system that supports important fishing grounds. Our objective was to investigate how physical ocean conditions impact distribution of seabirds along latitudinal gradients. We tested the hypothesis that seabird biogeographic patterns reflect differences in ocean conditions relating to the boundary between northern and southern shelf ecosystems. We used a grid-based approach to develop spatial means (1975–2014) of summertime seabird species' abundance, species' richness, and a multivariate seabird assemblage index to examine species composition. Seabird indices were linked to ocean conditions derived from a data-assimilative oceanographic model to quantify relationships between physics (e.g., temperature, salinity, and current velocity), bathymetry and seabirds along latitudinal gradients. Species assemblages reflected two main sources of variation, a mode for elevated richness and abundance, and a mode related to partitioning of inner/middle shelf species from outer shelf-slope species. Overall, species richness and abundance increased markedly at higher latitudes. We found that latitudinal changes in species assemblages, richness and abundance indicates a major shift around 59–60°N within inner and middle shelf regions, but not in the outer shelf. Within the middle shelf, latitudinal shifts in seabird assemblages strongly related to hydrographic structure, as opposed to the inner and outer shelf waters. As expected, elevated species richness and abundance was associated with major breeding colonies and within important coastal foraging areas. Our study also indicates that seabird observations supported the conclusion that the oceanographic model captured mesoscale variability of ocean conditions important for understanding seabird distributions and represents an important step for evaluating modeling and empirical studies. Biogeographic assessments of LMEs that integrate top predator distributions resolve critical habitat requirements and will benefit assessment of climate change impacts (e.g., sea-ice loss) predicted to affect high-latitude marine ecosystems.
KL Oakley, KJ Kuletz American Fisheries Society Symposium. 1996., 1996. ... The postspill populat... more KL Oakley, KJ Kuletz American Fisheries Society Symposium. 1996., 1996. ... The postspill population was 43% smaller than the prespill population, but we could not attribute the entire decline to the spill because a decline in this guillemot population may have predated the spill. ...
Studies of the impacts of climate change on Arctic marine ecosystems have largely centered on end... more Studies of the impacts of climate change on Arctic marine ecosystems have largely centered on endemic species and ecosystems, and the people who rely on them. Fewer studies have focused on the northward expansion of upper trophic level (UTL) subarctic species. We provide an overview of changes in the temporal and spatial distributions of subarctic fish, birds, and cetaceans, with a focus on the Pacific Arctic Region. Increasing water temperatures throughout the Arctic have increased “thermal habitat” for subarctic fish species, resulting in northward shifts of species including walleye pollock and pink salmon. Ecosystem changes are altering the community composition and species richness of seabirds in the Arctic, as water temperatures change the available prey field, which dictates the presence of planktivorous versus piscivorous seabird species. Finally, subarctic whales, among them killer and humpback whales, are arriving earlier, staying later, and moving consistently farther nor...
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