Moore Sue E.
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ArticleBowhead whale distribution and feeding near Barrow, Alaska, in late summer 2005–06(Arctic Institute of North America, 2010-06) Moore, Sue E. ; George, John C. ; Sheffield, Gay ; Bacon, Joshua ; Ashjian, Carin J.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.
ArticleClimate variability, oceanography, bowhead whale distribution, and Iñupiat subsistence whaling near Barrow, Alaska(Arctic Institute of North America, 2010-06) Ashjian, Carin J. ; Braund, Stephen R. ; Campbell, Robert G. ; George, John C. ; Kruse, Jack ; Maslowski, Wieslaw ; Moore, Sue E. ; Nicolson, Craig R. ; Okkonen, Stephen R. ; Sherr, Barry F. ; Sherr, Evelyn B. ; Spitz, Yvette H.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.
ArticleEuphausiid transport in the Western Arctic Ocean(Inter-Research, 2008-05-22) Berline, Leo ; Spitz, Yvette H. ; Ashjian, Carin J. ; Campbell, Robert G. ; Maslowski, Wieslaw ; Moore, Sue E.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.