Ecological Studies of Arctic Cod (<i>Boreogadus saida</i>) in Beaufort Sea Coastal Waters, Alaska

Craig, Peter; Griffiths, William; Haldorson, Lewis J.; McElderry, Howard

doi:10.1139/f82-057

Cited by 167 publications

(109 citation statements)

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“…Results of tagging studies show that white whales can dive to depths of more than1000 m and exhibit behaviors indicative of foraging at depths of several hundred metres (Martin et al, 1993). Conversely, Craig et al (1982) reported arctic cod abundance increased during late summer in an ice-free lagoon located along Alaska's north-central coast. Selection of ice-free habitat by some white whales in summer may be a response to foraging opportunities in nearshore waters, or habitat desired for skin molting, or both (Frost and Lowry, 1990).…”

Section: Seasonal Habitats and Trophic Relationshipsmentioning

confidence: 92%

Cetacean Habitat Selection in the Alaskan Arctic during Summer and Autumn

Moore¹,

DeMaster²,

Dayton³

2000

ARCTIC

118

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ABSTRACT. Ten years of sighting data from aerial surveys offshore of northern Alaska were analyzed to investigate seasonal variability in cetacean habitat selection. Distinct habitats were described for bowhead whales (Balaena mysticetus), white whales (Delphinapterus leucas), and gray whales (Eschrichtius robustus) on the basis of habitat selection ratios calculated for bathymetric and ice cover regimes. In summer, bowheads selected continental slope waters and moderate ice conditions; white whales selected slope and basin waters and moderate to heavy ice conditions; and gray whales selected coastal/shoal waters and open water. In autumn, bowheads selected inner shelf waters and light ice conditions; white whales selected outer shelf and slope waters and moderate to heavy ice; and gray whales selected coastal and shoal/trough habitats in light ice and open water. Habitat differences among species were significant in both seasons (ANOVA F > 28, p < 0.00001). Interseasonal depth and ice cover habitats were significantly different for bowhead whales (p < 0.00002), but not for gray whales (p > 0.35). White whale depth habitat was significantly different between seasons (p < 0.00002), but ice cover habitat was not (p < 0.08).Key words: Alaska, Arctic, Beaufort Sea, bowhead whale, Chukchi Sea, gray whale, habitat selection, white whale RÉSUMÉ. Des données d'observation réalisées sur dix années (1982 -1991) grâce à des relevés aériens au large de l'Alaska septentrional ont été analysées dans le cadre de recherches sur la variabilité saisonnière dans la sélection de l'habitat des cétacés. On a décrit des habitats distincts pour la baleine boréale (Balaena mysticetus), la baleine blanche (Delphinapterus leucas) et la baleine grise de Californie (Eschrichtius robustus) en se fondant sur les taux de sélection de l'habitat calculés pour le régime bathymétrique et celui de la couverture de glace. En été, la baleine boréale choisissait les eaux de la pente continentale et des conditions de glace modérée; la baleine blanche choisissait les eaux de la pente continentale et du bassin océanique, et des conditions de glace allant de modérée à épaisse; et la baleine grise choisissait des eaux côtières et de hauts-fonds ainsi que l'eau libre. En automne, la baleine boréale choisissait les eaux intérieures du plateau continental, où se trouvait une faible concentration de glace; la baleine blanche choisissait les eaux à l'extérieur du plateau et sur la pente, ainsi qu'une glace allant de modérée à épaisse; et la baleine grise choisissait des habitats côtiers et de hauts-fonds ou des fossés à faible concentration de glace et à eau libre. Les différences d'habitat entre les espèces étaient importantes durant les deux saisons (ANOVA F > 28, p < 0,00001). D'une saison à une autre, les habitats différaient sensiblement quant à la profondeur et à la couverture de glace pour la baleine boréale (p < 0,00002), mais pas pour la baleine grise (p > 0,35). La profondeur de l'habitat pour la baleine blanche variait sensiblement d'une saison à u...

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Section: Seasonal Habitats and Trophic Relationshipsmentioning

confidence: 92%

Cetacean Habitat Selection in the Alaskan Arctic during Summer and Autumn

Moore¹,

DeMaster²,

Dayton³

2000

ARCTIC

118

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“…More recent work reported normal fry development between ¡1.5 and 3.0°C, but highest survival rates occurred between 0.5 and 3.0°C (Sakurai et al 1998), observations supported by Fortier et al (2006). In coastal waters, adults occasionally tolerate temperatures as warm as »13°C, albeit they are more commonly found in waters no warmer than 6-7°C (Craig et al 1982).…”

Section: Introductionmentioning

confidence: 92%

Water mass and bathymetric characteristics of polar cod habitat along the continental shelf and slope of the Beaufort and Chukchi seas

2011

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Relatively little is known about the distribution of Wsh in deep water (>200 m) in the Beaufort Sea. Data collected by an Acoustic Doppler Current ProWler operated in the Chukchi and Beaufort seas in summer were examined for evidence of Wsh biomass detections between 18 and 400 m. The presence of Wsh in waters between 1 and 30 m was explored opportunistically with a non-scientiWc echo sounder. Evaluation of Wndings was enhanced by measurements of water column properties (temperature, salinity, Xuorescence and transmissivity). Relatively small shoals of Wsh were detected on the Chukchi shelf and eastern Chukchi shelf break, and also on the Alaskan and Canadian Beaufort shelves in the upper 20 m (T = 2-5°C). Much larger shoals (putative polar cod) were detected within Atlantic Water along the Beaufort continental slope (250-350 m) and near the bottom of Barrow and Mackenzie canyons, where temperatures were above 0°C. A warm-water plume of Alaska Coastal Current water with high concentrations of phytoplankton, zooplankton, and Wsh was found extending along the shelf 300 km eastward of Barrow Canyon. In contrast to the warm surface and Atlantic Water layers, very few Wsh were found in colder, intermediate depth PaciWc-origin water between them. The large biomass of Wsh in the Atlantic Water along the continental slope of the Chukchi and Beaufort seas represents previously undescribed polar cod habitat. It has important implications with regard to considerations of resource development in this area as well as understanding impacts of climate change.

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“…[175] They represent an important energy and Hg link between the base of sea ice food webs and higher trophic level predators that include Arctic cod (Boreogadus saida), ringed seals (Phoca hispida) and birds. [176][177][178][179][180][181] Gammarids in Lancaster Sound had Hg concentrations of 0.1 mg g À1 DW. [146] Arctic cod are thought to be a keystone species linking under ice food webs to many marine mammals and birds.…”

Section: Bottom Upmentioning

confidence: 99%

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

Douglas

Loseto²,

Macdonald³

et al. 2012

Environ. Chem.

121

147

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Environmental context. Mercury, in its methylated form, is a neurotoxin that biomagnifies in marine and terrestrial foodwebs leading to elevated levels in fish and fish-eating mammals worldwide, including at numerous Arctic locations. Elevated mercury concentrations in Arctic country foods present a significant exposure risk to Arctic people. We present a detailed review of the fate of mercury in Arctic terrestrial and marine ecosystems, taking into account the extreme seasonality of Arctic ecosystems and the unique processes associated with sea ice and Arctic hydrology.Abstract. This review is the result of a series of multidisciplinary meetings organised by the Arctic Monitoring and Assessment Programme as part of their 2011 Assessment 'Mercury in the Arctic'. This paper presents the state-of-the-art knowledge on the environmental fate of mercury following its entry into the Arctic by oceanic, atmospheric and terrestrial pathways. Our focus is on the movement, transformation and bioaccumulation of Hg in aquatic (marine and fresh water) and terrestrial ecosystems. The processes most relevant to biological Hg uptake and the potential risk associated with Hg exposure in wildlife are emphasised. We present discussions of the chemical transformations of newly deposited or transported Hg in marine, fresh water and terrestrial environments and of the movement of Hg from air, soil and water environmental compartments into food webs. Methylation, a key process controlling the fate of Hg in most ecosystems, and the role of trophic processes in controlling Hg in higher order animals are also included. Case studies on Eastern Beaufort Sea beluga (Delphinapterus leucas) and landlocked Arctic char (Salvelinus alpinus) are presented as examples of the relationship between ecosystem trophic processes and biologic Hg levels. We examine whether atmospheric mercury depletion events (AMDEs) contribute to increased Hg levels in Arctic biota and provide information on the links between organic carbon and Hg speciation, dynamics and bioavailability. Long-term sequestration of Hg into non-biological archives is also addressed. The review concludes by identifying major knowledge gaps in our understanding, including:(1) the rates of Hg entry into marine and terrestrial ecosystems and the rates of inorganic and MeHg uptake by Arctic microbial and algal communities; (2) the bioavailable fraction of AMDE-related Hg and its rate of accumulation by biota and (3) the fresh water and marine MeHg cycle in the Arctic, especially the marine MeHg cycle.

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Ecological Studies of Arctic Cod (Boreogadus saida) in Beaufort Sea Coastal Waters, Alaska

Cited by 167 publications

References 0 publications

Cetacean Habitat Selection in the Alaskan Arctic during Summer and Autumn

Cetacean Habitat Selection in the Alaskan Arctic during Summer and Autumn

Water mass and bathymetric characteristics of polar cod habitat along the continental shelf and slope of the Beaufort and Chukchi seas

The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

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