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  • 1
    Publication Date: 2022-05-25
    Description: Author Posting. © Arctic Institute of North America, 2010. This article is posted here by permission of Arctic Institute of North America for personal use, not for redistribution. The definitive version was published in Arctic 63 (2010): 179-194.
    Description: The annual migration of bowhead whales (Balaena mysticetus) past Barrow, Alaska, has provided subsistence hunting to Iñupiat for centuries. Bowheads recurrently feed on aggregations of zooplankton prey near Barrow in autumn. The mechanisms that form these aggregations, and the associations between whales and oceanography, were investigated using field sampling, retrospective analysis, and traditional knowledge interviews. Oceanographic and aerial surveys were conducted near Barrow during August and September in 2005 and 2006. Multiple water masses were observed, and close coupling between water mass type and biological characteristics was noted. Short-term variability in hydrography was associated with changes in wind speed and direction that profoundly affected plankton taxonomic composition. Aggregations of ca. 50–100 bowhead whales were observed in early September of both years at locations consistent with traditional knowledge. Retrospective analyses of records for 1984–2004 also showed that annual aggregations of whales near Barrow were associated with wind speed and direction. Euphausiids and copepods appear to be upwelled onto the Beaufort Sea shelf during Eor SEwinds. A favorable feeding environment is produced when these plankton are retained and concentrated on the shelf by the prevailing westward Beaufort Sea shelf currents that converge with the Alaska Coastal Current flowing to the northeast along the eastern edge of Barrow Canyon.
    Description: This work was supported by NSF Grants OPPPP-0436131 to C. Ashjian (S. Braund Subcontract), OPPPP-0436110 to R. Campbell, OPPPP-0436127 to W. Maslowski, OPPPP-0436009 to C. Nicolson and J. Kruse, OPPPP-043166 to S. Okkonen, and OPPPP-0435956 to Y. Spitz, E. Sherr, and B. Sherr.
    Keywords: Bowhead whale ; Plankton ; Oceanography ; Beaufort Sea ; Subsistence whaling
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 2
    Publication Date: 2022-05-25
    Description: Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 3 (2012): 204-207, doi:10.5670/oceanog.2012.96.
    Description: Scientific and political interests at the poles are significant and rapidly increasing, driven in part by the effects of climate change and emerging geopolitical realities. The polar regions provide important services to global ecosystems and humankind, ranging from food and energy to freshwater and biodiversity. Yet the poles are experiencing changes at rates that far outpace the rest of the planet. Coastal Arctic communities are impacted by climate change through coastal erosion, sea level rise, ice loss, and altered marine food webs, threatening the future of their subsistence lifestyle. Climate change has dramatically increased the melt rate of ice sheets and glaciers at both poles and has the potential to significantly raise sea level worldwide. Oil and gas drilling as well as transportation in the Arctic have reached all-time high levels, in part because of reduced sea ice cover. Tourism is a growing industry at both poles, bringing more than 20,000 tourists each year to the western Antarctic Peninsula alone. The collateral effects of human activities include the potential for pollution of the marine environment, particularly through spills of hydrocarbons. Our ability to understand the effects of such activities and mishaps is limited, particularly in ice-covered areas during winter.
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 3
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C00A11, doi:10.1029/2008JC004870.
    Description: Wind-driven changes in the path of warm Bering/Chukchi waters carried by the Alaska Coastal Current (ACC) through Barrow Canyon during late summer are described from high-resolution hydrography, acoustic Doppler current profiler–measured currents, and satellite-measured sea surface temperature imagery acquired from mid-August to mid-September 2005–2007 near Barrow, Alaska. Numerical simulations are used to provide a multidecadal context for these observational data. Four generalized wind regimes and associated circulation states are identified. When winds are from the east or east-southeast, the ACC jet tends to be relatively strong and flows adjacent to the shelf break along the southern flank of Barrow Canyon. These easterly winds drive inner shelf currents northwestward along the Alaskan Beaufort coast where they oppose significant eastward intrusions of warm water from Barrow Canyon onto the shelf. Because these easterly winds promote sea level set down over the Beaufort shelf and upwelling along the Beaufort slope, the ACC jet necessarily becomes weaker, broader, and displaced seaward from the Beaufort shelf break upon exiting Barrow Canyon. Winds from the northeast promote separation of the ACC from the southern flank of Barrow Canyon and establish an up-canyon current along the southern flank that is fed in part by waters from the western Beaufort shelf. When winds are weak or from the southwest, warm Bering/Chukchi waters from Barrow Canyon intrude onto the western Beaufort shelf.
    Description: This work was supported in 2005 and 2006 by NSF grants OPP-0436131 and OPP-0436166. In 2007, this work received support through Woods Hole Oceanographic Institution- NOAA Cooperative Institute for Climate and Ocean Research Cooperative Agreement NA17RJ1223 and University of Alaska Fairbanks-NOAA Cooperative Institute for Arctic Research Cooperative Agreement NA17RJ1224. Additional support was provided by the James M. and Ruth P. Clark Arctic Research Initiative Fund at the Woods Hole Oceanographic Institution.
    Keywords: Beaufort index
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 4
    Publication Date: 2022-05-25
    Description: Author Posting. © Arctic Institute of North America, 2010. This article is posted here by permission of Arctic Institute of North America for personal use, not for redistribution. The definitive version was published in Arctic 63 (2010): 195-205.
    Description: Aerial surveys for bowhead whales were conducted in conjunction with oceanographic sampling near Barrow, Alaska, in late summer of 2005 and 2006. In 2005, 145 whales were seen, mostly in two distinct aggregations: one (ca. 40 whales) in deep water in Barrow Canyon and the other (ca. 70 whales) in very shallow (〈 10 m) water just seaward of the barrier islands. Feeding behaviours observed in the latter group included whales lying on their sides with mouths agape and groups of 5–10 whales swimming synchronously in turbid water. In 2006, 78 bowheads were seen, with ca. 40 whales feeding in dispersed groups of 3–11 whales. Feeding behaviours observed included surface skimming, echelon swimming, and synchronous diving and surfacing. Surfacing behaviour included head lunges by single animals and groups of 2–4 whales. Of 29 whales harvested at Barrow, 24 had been feeding. Euphausiids were the dominant prey in 2006 (10 of 13 stomachs), but not in 2005 (4 of 11 stomachs). Copepods were the dominant prey in the stomachs of three whales harvested near Barrow Canyon in 2005. Mysiids were the dominant prey in four stomachs, isopods in two, and amphipods in one although these taxa were not routinely captured during plankton sampling conducted in the weeks prior to the autumn harvest.
    Description: Much of the field portion of this work was supported by the NSF/SNACS program.
    Keywords: Bowhead whale ; Feeding ; Functional anatomy ; Zooplankton ; Western Arctic ; Beaufort Sea ; Aerial surveys
    Repository Name: Woods Hole Open Access Server
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  • 5
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 115 (2010): C10015, doi:10.1029/2009JC005387.
    Description: We have developed a coupled 3-D pan-Arctic biology/sea ice/ocean model to investigate the impact of declining Arctic sea ice on the marine planktonic ecosystem over 1988–2007. The biophysical model results agree with satellite observations of a generally downward trend in summer sea ice extent during 1988–2007, resulting in an increase in the simulated photosynthetically active radiation (PAR) at the ocean surface and marine primary productivity (PP) in the upper 100 m over open water areas of the Arctic Ocean. The simulated Arctic sea ice thickness has decreased steadily during 1988–2007, leading to an increase in PAR and PP in sea ice-covered areas. The simulated total PAR in all areas of the Arctic Ocean has increased by 43%, from 146 TW in 1988 to 209 TW in 2007; the corresponding total PP has increased by 50%, from 456 Tg C yr−1 in 1988 to 682 Tg C yr−1 in 2007. The simulated PAR and PP increases mainly occur in the seasonally and permanently ice-covered Arctic Ocean. In addition to increasing PAR, the decline in sea ice tends to increase the nutrient availability in the euphotic zone by enhancing air-sea momentum transfer, leading to strengthened upwelling and mixing in the water column and therefore increased nutrient input into the upper ocean layers from below. The increasing nutrient availability also contributes to the increase in the simulated PP, even though significant surface nutrient drawdown in summer is simulated. In conjunction with increasing surface absorption of solar radiation and rising surface air temperature, the increasing surface water temperature in the Arctic Ocean peripheral seas further contributes to the increase in PP. As PP has increased, so has the simulated biomass of phytoplankton and zooplankton.
    Description: We gratefully acknowledge the support of NSF (grants ARC‐0629326, ARC‐0629312, ARC‐0629348, ARC‐0629495, and ARC‐0805789).
    Keywords: Sea ice ; Arctic marine ecosystem ; Primary productivity
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 6
    Publication Date: 2022-05-25
    Description: Author Posting. © Inter-Research, 2008. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 360 (2008): 163-178, doi:10.3354/meps07387.
    Description: Euphausiids are commonly found in the stomachs of bowhead whales Balaena mysticetus hunted near Barrow, Alaska; however, no evidence exists of a self-sustaining population in this region. To explain euphausiid presence near Barrow, their transport from the northern Bering Sea was investigated through particle tracking experiments using velocity fields from an ocean general circulation model in 4 contrasted circulation scenarios (1997, 1998, 2002 and 2003). Euphausiids were released during their spawning season (April-June) in the bottom and surface layers in the northern Bering Sea, their endemic region, and tracked through the Chukchi-Beaufort Sea. Results show that both Anadyr Gulf and Shpanberg Strait are potential regions of origin for euphausiids. Topographically steered bottom particles have 4 to 5 times higher probability of reaching Barrow than surface particles (ca. 95% versus 20% of particles). As euphausiids are often found near the bottom on the northern Bering shelf, this suggests a very high probability of euphausiids reaching Barrow, making this location a privileged area for whale feeding. The main pathways to Barrow across the Chukchi Sea shelf are Central Valley (CV) and Herald Valley (HV). The transit to Barrow takes 4 to 20 mo. Arrivals at Barrow have 2 peaks at ca. 200 d (fall, CV particles) and 395 d after release (spring, mixed CV and HV) on average, because of the seasonal cycle of the Chukchi Sea currents. Elevated euphausiid abundance in the fall at Barrow is favored by a high Bering Strait northward transport and by southerly winds, driving organisms through CV rather than through the HV pathway.
    Description: This work was supported by NSF grant # OPP-0435956.
    Description: 2013-05-22
    Keywords: Euphausiid ; Thysanoessa spp. ; Bowhead whale ; Balaena mysticetus ; Western Arctic Ocean ; Chukchi Sea ; Lagrangian drifter ; Zooplankton advection model
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 7
    Publication Date: 2022-05-26
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 119 (2014): 297-312, doi:10.1002/2013JC009301.
    Description: A coupled biophysical model is used to examine the impact of the great Arctic cyclone of early August 2012 on the marine planktonic ecosystem in the Pacific sector of the Arctic Ocean (PSA). Model results indicate that the cyclone influences the marine planktonic ecosystem by enhancing productivity on the shelves of the Chukchi, East Siberian, and Laptev seas during the storm. Although the cyclone's passage in the PSA lasted only a few days, the simulated biological effects on the shelves last 1 month or longer. At some locations on the shelves, primary productivity (PP) increases by up to 90% and phytoplankton biomass by up to 40% in the wake of the cyclone. The increase in zooplankton biomass is up to 18% on 31 August and remains 10% on 15 September, more than 1 month after the storm. In the central PSA, however, model simulations indicate a decrease in PP and plankton biomass. The biological gain on the shelves and loss in the central PSA are linked to two factors. (1) The cyclone enhances mixing in the upper ocean, which increases nutrient availability in the surface waters of the shelves; enhanced mixing in the central PSA does not increase productivity because nutrients there are mostly depleted through summer draw down by the time of the cyclone's passage. (2) The cyclone also induces divergence, resulting from the cyclone's low-pressure system that drives cyclonic sea ice and upper ocean circulation, which transports more plankton biomass onto the shelves from the central PSA. The simulated biological gain on the shelves is greater than the loss in the central PSA, and therefore, the production on average over the entire PSA is increased by the cyclone. Because the gain on the shelves is offset by the loss in the central PSA, the average increase over the entire PSA is moderate and lasts only about 10 days. The generally positive impact of cyclones on the marine ecosystem in the Arctic, particularly on the shelves, is likely to grow with increasing summer cyclone activity if the Arctic continues to warm and the ice cover continues to shrink.
    Description: This work is supported by the NSF Office of Polar Programs and the NASA Cryosphere Program.
    Keywords: Cyclone effects on biology ; Arctic Ocean ; Ocean mixing
    Repository Name: Woods Hole Open Access Server
    Type: Article
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