The Barrow Symposium on Sea Ice, 2000: Evaluation of One Means of Exchanging Information between Subsistence Whalers and Scientists

A Barrow Symposium on Sea Ice (BSSI) was held in early winter 2000. The National Science Foundation (U.S.) funded this symposium as the keystone event in a project designed to ally traditional ecological knowledge (TEK) with formal ice research and remote sensing. The goal of the project was to stimulate substantive interactions between scientists and technicians who study sea ice on one hand, and Inupiat Eskimos (primarily whaling captains and their crews) who use the ice routinely for travel, camping, and hunting, on the other. From different perspectives, at different scales, and for different purposes, the two groups have accumulated extensive knowledge of ice characteristics and dynamics. We evaluate strengths and weaknesses of the workshop format as a means of exchanging information between scientific and traditional knowledge.... To continue to develop the interactions and shared purposes that characterized the BSSI, a core group of participants needs to meet periodically to review progress on sea ice research in the region, and to seek ways to promote further collaboration between ice observers from the subsistence community and scientists. Research on sea ice appears likely to continue to flourish near Barrow. Both whalers and scientists are eager to share information and insights. Facilitating that exchange is not a trivial task. To be successful in the long run, the promising start made by the BSSI needs to be followed up with refinements in collaborative field research, as well as by regular opportunities for scientists and whalers to learn from one another

Winter Movements of Bowhead Whales (Balaena mysticetus) in the Bering Sea

Working with subsistence whale hunters, we tagged bowhead whales (Balaena mysticetus) with satellite-linked transmitters and documented their movements in the Bering Sea during two winters. We followed 11 whales through the winter of 2008 – 09 and 10 whales in 2009 – 10. The average date that bowhead whales entered the Bering Sea was 14 December in 2008 and 26 November in 2009. All but one tagged whale entered the Bering Sea west of Big Diomede Island. In the winter of 2008 – 09, whales were distributed in a line extending from the Bering Strait to Cape Navarin, whereas in 2009 – 10, the distribution shifted south of St. Lawrence Island, extending from Cape Navarin to St. Matthew Island. Bowhead whales were most likely to be found in areas with 90% – 100% sea-ice concentration and were generally located far from the ice edge and polynyas. The average date whales left the Bering Sea was 12 April in 2009 and 22 April in 2010. During the spring migration, all whales but one traveled north along the Alaska coast to summering grounds in the Canadian Beaufort. The remaining whale migrated a month later and traveled up the northern coast of Chukotka, where it was located when the tag stopped transmitting in August. It is unlikely that this whale migrated to the Beaufort Sea before returning south to winter within the Bering Sea, indicating the movements of bowhead whales are more complex than generally believed. Declining sea ice in the Bering Sea may result in the expansion of commercial fisheries and shipping; areas where such activities may overlap the winter range of bowhead whales include the Bering and Anadyr straits, the eastern edge of Anadyr Bay, and St. Matthew Island.Avec l’aide de pêcheurs de baleine de subsistance, nous avons marqué des baleines boréales (Balaena mysticetus) au moyen de transmetteurs en liaison avec un satellite et répertorié leurs mouvements au cours de deux hivers dans la mer de Béring. Nous avons suivi 11 baleines pendant l’hiver 2008-2009 et dix baleines en 2009-2010. En 2008, les baleines boréales sont entrées dans la mer de Béring le 14 décembre en moyenne, tandis qu’en 2009, elles sont arrivées le 26 novembre. À l’exception d’une baleine, toutes les baleines marquées ayant pénétré dans la mer de Béring sont passées par l’ouest de la grande île Diomède. À l’hiver 2008-2009, le parcours des baleines s’étendait en ligne depuis le détroit de Béring jusqu’au cap Navarin, tandis qu’en 2009-2010, le parcours s’est déplacé vers le sud de l’île Saint-Laurent, s’étendant ainsi du cap Navarin jusqu’à l’île Saint-Mathieu. Les baleines boréales étaient plus susceptibles de se retrouver dans les endroits dont la glace de mer a une concentration allant de 90 à 100 %. Généralement, elles se tiennent loin des lisières de glace et des polynies. En 2009, la date moyenne à laquelle les baleines ont quitté la mer de Beaufort était le 12 avril, tandis qu’en 2010, cette date était le 22 avril. Pendant la migration printanière, toutes les baleines, sauf une, se sont déplacées vers le nord le long de la côte de l’Alaska pour se rendre à leur aire d’estivage dans la partie canadienne de Beaufort. L’autre baleine a fait sa migration un mois plus tard et s’est déplacée le long de la côte nord de Tchoukotka, là où elle avait été repérée lorsque son marqueur a cessé ses transmissions en août. Il est improbable que cette baleine ait migré dans la mer de Beaufort avant de revenir vers le sud pour passer l’hiver dans la mer de Béring, ce qui indique que les mouvements des baleines boréales sont plus complexes qu’on ne le croyait antérieurement. La perte de glace de mer dans la mer de Béring pourrait se traduire par l’intensification des activités de pêche commerciale et d’expédition de marchandises. Les endroits où ces activités pourraient chevaucher le parcours d’hiver des baleines boréales comprennent les détroits de Béring et d’Anadyr, le côté est de la baie d’Anadyr et l’île Saint-Mathieu

Movements and Inferred Foraging by Bowhead Whales in the Canadian Beaufort Sea during August and September, 2006–12

Each spring, most bowhead whales of the Bering-Chukchi-Beaufort (BCB) population migrate to the southeast Beaufort Sea and summer in Canadian waters. In August and September, they form aggregations, which are known to occur mainly in the shallow, shelf waters when oceanographic conditions promote concentration of their zooplankton prey. The movements of individual bowheads while they occupy these late summer habitats are less well known; our knowledge is based on photographic evidence and limited tagging studies conducted from 1982 to 2000. In this study, 85% (17) of the 20 satellite-tagged whales that could have spent some time in the Canadian portion of the Beaufort Sea during late summer 2006 to 2012 spent all or part of August and September there. We analyzed location data for 16 whales, using a two-state switching correlated random walk (CRW) behavioural model, and classified locations in the Canadian waters as associated with lingering behaviour (inferred foraging) or directed travel. We found that these whales spent the greatest proportion of their time lingering (59%), followed by traveling (22%), and transitioning between lingering and traveling (19%). Using only lingering locations for these tagged whales in all study years pooled, we calculated kernel densities and defined five areas within the 75% density contour as aggregation areas. Together, the five aggregation areas we defined comprised 25 341 km2, 14.1% of the total area used by these tagged whales in Canadian waters during August and September of the deployment years. Three aggregation areas were located in shallow waters of the Beaufort Sea Shelf and were used almost exclusively by immature tagged whales in our sample. Two other aggregation areas were observed, one in Darnley Bay and one in Viscount Melville Sound in the Canadian Arctic Archipelago. Each of these was used by one mature whale. Tagged whales were observed to use one or two aggregation areas in a single season, and rarely more. The proportion of lingering time spent in each aggregation area was highly variable among individuals. The largest aggregation area (10 877 km2), located over the Beaufort Shelf north of the Tuktoyaktuk Peninsula (5 – 52 m depth), was used by 13 of the 16 tagged whales, almost exclusively by the immature whales, including three of four that were tracked in two consecutive summers. The Beaufort Shelf overall (and possibly the Tuktoyaktuk Shelf, including the Outer Shelf, in particular) was especially important for immature bowhead whales, while mature whales used habitats beyond the Beaufort Shelf during late summer. Findings may be important to inform both decisions on management and mitigative actions relating to bowhead whale use of the Beaufort Shelf and studies that aim to improve our understanding of the prey base of BCB bowhead whales in the Canadian Beaufort Sea region.Tous les printemps, la plupart des baleines boréales de la population de Béring-Tchouktches-Beaufort (BCB) migrent vers le sud-est de la mer de Beaufort et passent l’été dans les eaux canadiennes. En août et en septembre, elles forment des agrégations, principalement dans les eaux de plateau peu profondes lorsque les conditions océanographiques favorisent la concentration du zooplancton, qui leur sert de proie. Individuellement, les déplacements des baleines boréales qui occupent ces habitats en fin d’été sont moins connus. Nos connaissances sont fondées sur des preuves photographiques ainsi que sur des études de marquage restreint réalisées entre 1982 et 2000. Dans le cadre de la présente étude, 85 % (17) des 20 baleines pistées par satellite qui auraient pu passer du temps dans la partie canadienne de la mer de Beaufort vers la fin de l’été de 2006 à 2012 y ont passé les mois d’août et de septembre, en totalité ou en partie. Nous avons analysé les données de localisation de16 baleines à l’aide d’un modèle de comportement de marche aléatoire corrélée à commutation binaire, et classé les localisations dans les eaux canadiennes comme relevant d’un comportement de traînage (présupposition de comportement d’alimentation) ou comme relevant de déplacements orientés. Nous avons constaté que ces baleines passaient la plus grande partie de leur temps à traîner (59 %), à se déplacer (22 %), et à faire la transition entre traîner et se déplacer (19 %). En n’utilisant que les localisations de traînage des baleines pistées pour toutes les années à l’étude, nous avons calculé les noyaux de densité et défini cinq zones à l’intérieur du contour de la densité de 75 % à titre de zones d’agrégation. Ensemble, les cinq zones d’agrégation que nous avons définies s’étendent sur 25 341 km2, soit 14,1 % de la zone totale utilisée par ces baleines pistées dans les eaux canadiennes en août et en septembre des années de déploiement. Trois zones d’agrégation étaient situées dans les eaux peu profondes du plateau de la mer de Beaufort, et ces zones étaient principalement utilisées par les baleines immatures pistées dans notre échantillon. Deux autres agrégations ont été observées, une dans la baie Darnley et l’autre dans le détroit du Vicomte de Melville situés dans la partie canadienne de l’archipel Arctique. Chacun de ces endroits était utilisé par une baleine adulte. Des baleines pistées ont été aperçues dans une ou deux zones d’agrégation au cours d’une même saison, rarement plus. La proportion du temps passé à traîner dans chaque zone d’agrégation variait beaucoup d’un individu à l’autre. La plus grande zone d’agrégation (10 877 km2), située sur le plateau de la mer de Beaufort au nord de la péninsule de Tuktoyaktuk (d’une profondeur de 5 à 52 m), était utilisée par 13 des 16 baleines pistées, presque toujours des baleines immatures, dont trois sur quatre ont été repérées pendant deux étés consécutifs. Dans l’ensemble, le plateau de la mer de Beaufort (et peut-être le plateau de Tuktoyaktuk, y compris la zone externe du plateau, en particulier) revêtait une importance particulière pour les baleines boréales immatures, tandis que les baleines adultes se servaient des habitats situés au-delà du plateau de la mer de Beaufort vers la fin de l’été. Ces constatations pourraient jouer un rôle important quand vient le temps d’éclairer tant les décisions en matière de gestion et de mesures d’atténuation se rapportant à l’utilisation que fait la baleine boréale du plateau de la mer de Beaufort que les études visant à améliorer notre compréhension de la composition des proies des baleines boréales de BCB dans la région canadienne de la mer de Beaufort

Ecological characteristics of core-use areas used by Bering–Chukchi–Beaufort (BCB) bowhead whales, 2006–2012

© The Author(s), 2014]. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Progress in Oceanography 136 (2015): 201-222, doi:10.1016/j.pocean.2014.08.012.The Bering–Chukchi–Beaufort (BCB) population of bowhead whales (Balaena mysticetus) ranges across the seasonally ice-covered waters of the Bering, Chukchi, and Beaufort seas. We used locations from 54 bowhead whales, obtained by satellite telemetry between 2006 and 2012, to define areas of concentrated use, termed “core-use areas”. We identified six primary core-use areas and describe the timing of use and physical characteristics (oceanography, sea ice, and winds) associated with these areas. In spring, most whales migrated from wintering grounds in the Bering Sea to the Cape Bathurst polynya, Canada (Area 1), and spent the most time in the vicinity of the halocline at depths <75 m, which are within the euphotic zone, where calanoid copepods ascend following winter diapause. Peak use of the polynya occurred between 7 May and 5 July; whales generally left in July, when copepods are expected to descend to deeper depths. Between 12 July and 25 September, most tagged whales were located in shallow shelf waters adjacent to the Tuktoyaktuk Peninsula, Canada (Area 2), where wind-driven upwelling promotes the concentration of calanoid copepods. Between 22 August and 2 November, whales also congregated near Point Barrow, Alaska (Area 3), where east winds promote upwelling that moves zooplankton onto the Beaufort shelf, and subsequent relaxation of these winds promoted zooplankton aggregations. Between 27 October and 8 January, whales congregated along the northern shore of Chukotka, Russia (Area 4), where zooplankton likely concentrated along a coastal front between the southeastward-flowing Siberian Coastal Current and northward-flowing Bering Sea waters. The two remaining core-use areas occurred in the Bering Sea: Anadyr Strait (Area 5), where peak use occurred between 29 November and 20 April, and the Gulf of Anadyr (Area 6), where peak use occurred between 4 December and 1 April; both areas exhibited highly fractured sea ice. Whales near the Gulf of Anadyr spent almost half of their time at depths between 75 and 100 m, usually near the seafloor, where a subsurface front between cold Anadyr Water and warmer Bering Shelf Water presumably aggregates zooplankton. The amount of time whales spent near the seafloor in the Gulf of Anadyr, where copepods (in diapause) and, possibly, euphausiids are expected to aggregate provides strong evidence that bowhead whales are feeding in winter. The timing of bowhead spring migration corresponds with when zooplankton are expected to begin their spring ascent in April. The core-use areas we identified are also generally known from other studies to have high densities of whales and we are confident these areas represent the majority of important feeding areas during the study (2006–2012). Other feeding areas, that we did not detect, likely existed during the study and we expect core-use area boundaries to shift in response to changing hydrographic conditions.This study is part of the Synthesis of Arctic Research (SOAR) and was funded in part by the U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program through Interagency Agreement No. M11PG00034 with the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), Office of Oceanic and Atmospheric Research (OAR), Pacific Marine Environmental Laboratory (PMEL). Funding for this research was mainly provided by U.S. Minerals Management Service (now Bureau of Ocean Energy Management) under contracts M12PC00005, M10PS00192, and 01-05-CT39268, with the support and assistance from Charles Monnett and Jeffery Denton, and under Interagency Agreement No. M08PG20021 with NOAA-NMFS and Contract No. M10PC00085 with ADF&G. Work in Canada was also funded by the Fisheries Joint Management Committee, Ecosystem Research Initiative (DFO), and Panel for Energy Research and Development

Effect of Climatic Warming on the Pacific Walrus, and Potential Modification of Its Helminth Fauna [Critical Comment]

The decreasing extent of sea-ice in the arctic basin as a consequence of climatic warming is modifying the behavior and diets of pagophilic pinnipeds, including the Pacific walrus, Odobenus rosmarus divergens Illiger, the species emphasized here. Mammals such as the walrus and bearded seal, Erignathus barbatus (Erxleben), cannot remain associated with the sea-ice, and continue to feed on their usual diet of benthic invertebrates inhabiting coastal waters to a depth of approximately 100 m, when the northwestward retreating ice reaches deep waters beyond the margins of the continental shelf. With reduction of their customary substrate (ice), the walrus has become more pelagic and preys more often on ringed seals, Phoca hispida Schreber. Dietary changes, with modifications of helminth faunas, may be induced by various factors. Increased consumption of mammals or their remains by walruses may lead to a higher prevalence of trichinellosis in them and to more frequent occurrence in indigenous peoples inhabiting the arctic coasts. To assess predicted effects on the composition of helminth fauna of the walrus, we recommend systematic surveys of their helminths as part of research on effects of climatic warming