Thick-billed murres and black guillemots in the Barrow Strait area, N.W.T., during spring: diets and food availability along ice edges

1980 ◽  
Vol 58 (11) ◽  
pp. 2120-2140 ◽  
Author(s):  
Michael S. W. Bradstreet
Keyword(s):  
Water Column ◽  
Food Availability ◽  
Dry Weight ◽  
Boreogadus Saida ◽  
Associated Fauna ◽  
Uria Lomvia ◽  
Arctic Cod ◽  
Cepphus Grylle ◽  
Sea Bottom ◽  
Landfast Ice

From 5 June to 4 July 1976, I collected 98 thick-billed murres (Uria lomvia) and 47 black guillemots (Cepphus grylle) at ice edges in Barrow Strait, N.W.T., for diet studies. Alcids were collected at coastal ice edges and at the edges of landfast ice farther offshore; in both habitats food availability was also studied. At coastal ice edges, murre diet was dominated by Arctic cod (Boreogadus saida, 14% of dry weight biomass) and the amphipod Onisimus litoralis (18%); guillemot diet was dominated by cod (99%), decapods (0.4%), and amphipods (0.2%). At offshore ice edges murres took cod (96%), Parathemisto (2%), and Onisimus glacialis (2%); guillemots took cod (54%), O. glacialis (35%), and Apherusa glacialis (5%). Morisita's overlap values showed that diets of these two alcids were more similar at offshore than at coastal ice edges and that there were considerable habitat-related differences in diet. Data on food availability suggested that at offshore ice edges, murres were feeding in the water column and at the undersurface of the landfast ice; guillemots fed almost solely at the ice undersurface. At coastal ice edges, both alcids were probably feeding at the ice undersurface and on the sea bottom; in addition, murres fed in the water column. The importance of epontic (= ice-associated) fauna in the diets of alcids during spring is discussed.

Diet and foraging ecology of Black Guillemots in northeastern Hudson Bay

1987 ◽  
Vol 65 (5) ◽  
pp. 1257-1263 ◽  
Author(s):  
D. K. Cairns
Keyword(s):  
Foraging Ecology ◽  
Canadian Arctic ◽  
Open Water ◽  
Hudson Bay ◽  
Boreogadus Saida ◽  
Foraging Habitat ◽  
Decapod Crustaceans ◽  
Cepphus Grylle ◽  
Landfast Ice ◽  
Eastern Canadian Arctic

I examined diet and foraging habitat selection by Black Guillemots (Cepphus grylle) in the eastern Canadian arctic. Birds fed on fish (Boreogadus saida, Stichaeus punctatus, Eumesogrammus praecisus) and mysid, amphipod, and decapod crustaceans. Guillemots concentrated at landfast ice edges early in the breeding season. Open-water foraging occurred principally in waters 10–30 m deep within 13 km of breeding colonies. Guillemots were aggregated on the water, but their distributions were not correlated with those of schooling prey. Guillemots feeding in open water obtained much of their food on the bottom, but some prey was likely taken during transit to and from the bottom.

scholarly journals Impacts of temperature and food availability on the condition of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogrammus)

2018 ◽  
Vol 75 (7) ◽  
pp. 2370-2385 ◽  
Author(s):  
Brittany L Koenker ◽  
Louise A Copeman ◽  
Benjamin J Laurel
Keyword(s):  
Food Availability ◽  
Thermal Tolerance ◽  
Walleye Pollock ◽  
Boreogadus Saida ◽  
Food Ration ◽  
Arctic Cod ◽  
Larval Stages ◽  
First Feeding ◽  
Energetic Condition ◽  
Larval Condition

Abstract The Arctic marine environment is rapidly changing with rising sea surface temperatures, declining sea ice habitat and projected increases in boreal species invasions. The success of resident Arctic fish will depend on both their thermal tolerance and their ability to cope with changing trophic interactions. Larval fish energetic condition is closely associated with mortality rates and therefore provides an indicator of overall well-being or fitness. In this study, we experimentally determined larval morphometric and lipid-based condition in an Arctic gadid (Arctic cod, Boreogadus saida) and a boreal gadid (walleye pollock, Gadus chalcogrammus) in response to different temperatures and food rations. Our results suggest that larval condition is highly sensitive to both factors but varies in a species- and ontogenetic-dependent manner. Results indicated that condition metrics based on length–weight relationships were not as sensitive as those based on lipid storage. Further, condition metrics changed with ontogeny and were best used within a developmental stage rather than across developmental stages. As expected, larval condition in first-feeding Arctic cod was higher at colder temperatures (2–5°C) than in the boreal gadid (5–12°C). However, at more developed larval stages the peak condition for Arctic cod was at warmer temperatures (7°C), while walleye pollock had the same thermal optimum as during earlier stages. Arctic cod were more sensitive to food ration at first feeding than walleye pollock, however; at later larval stages both species had a negative condition response to low food ration, especially at elevated temperatures (5 vs. 7°C). The lower thermal tolerance of Arctic cod, coupled with a higher sensitivity to food availability indicates that Arctic cod are particularly vulnerable to on-going environmental change. Arctic cod is a lipid-rich keystone species and therefore a reduction in their energetic condition during summer has the potential to affect the health of higher trophic levels throughout the Alaskan Arctic.

Thick-billed murres and black guillemots in the Barrow Strait area, N.W.T., during spring: distribution and habitat use

1979 ◽  
Vol 57 (9) ◽  
pp. 1789-1802 ◽  
Author(s):  
Michael S. W. Bradstreet
Keyword(s):  
Habitat Use ◽  
Canadian Arctic ◽  
Open Water ◽  
High Arctic ◽  
Marine Water ◽  
Uria Lomvia ◽  
Cepphus Grylle ◽  
Aerial Surveys ◽  
Landfast Ice ◽  
Small Cracks

During the "spring" periods of 1974–1976, Uria lomvia and Cepphus grylle in the central Canadian Arctic were concentrated in the Barrow Strait area. Aerial surveys indicated that densities of both species were higher in interface habitats (i.e. along boundaries of land or ice and marine water) than in areas of open water distant from coasts or landfast ice. Murres occurred in higher densities along offshore than along coastal landfast ice edges; guillemots showed no preference between these two habitats. Guillemots, but not murres, occurred in small cracks in landfast ice. The overall preference of murres and guillemots for interface habitats was compared with the results of two other studies of the distribution of these alcids in high arctic areas.

scholarly journals Isotopic Investigations of Seabirds of the North Water Polynya: Contrasting Trophic Relationships Between the Eastern and Western Sectors

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Keith A. Hobson ◽  
Grant Gilchrist ◽  
Knud Falk
Keyword(s):  
Trophic Level ◽  
Boreogadus Saida ◽  
Uria Lomvia ◽  
Alle Alle ◽  
Rissa Tridactyla ◽  
The North ◽  
North Water Polynya ◽  
Cepphus Grylle ◽  
North Water ◽  
Larus Hyperboreus

Abstract We used δ15N and δ13C analyses of blood, muscle, and liver tissues to evaluate similarity of diet among five seabird species: Black Guillemot (Cepphus grylle), Black-legged Kittiwake (Rissa tridactyla), Dovekie (Alle alle), Glaucous Gull (Larus hyperboreus), and Thick-billed Murre (Uria lomvia) nesting at Coburg Island on the west and Hakluyt Island on the east side of the North Water Polynya between Ellesmere Island, Canada, and northwest Greenland. We hypothesized that dietary differences should occur because the two neighboring sites are subject to different oceanographic conditions, one result of which is differential timing of spring open water. Relative trophic level, derived from tissue δ15N values, ranged from 3.6 for Dovekie from Hakluyt Island to 4.7 for late-breeding-season diets of Thick-billed Murre adults from Coburg Island. At Coburg Island, trophic level of hatching year (HY) kittiwakes, murres, and Glaucous Gulls was higher than that for adults. This pattern was not found at Hakluyt Island, where chicks of all species generally occupied lower trophic positions. These findings suggest that lower-trophic-level prey were more important to Hakluyt Island seabirds, possibly due to lower availability of arctic cod (Boreogadus saida). Investigaciones Isotópicas de Aves Marinas en el Canal Aguas del Norte: Contrastando las Relaciones Tróficas entre los Sectores Este y Oeste Resumen. Usamos análisis de δ15N y δ13C en tejidos sanguineos, musculares y hepáticos para evaluar la similitud en la dieta entre cinco especies de aves marinas (Cepphus grylle, Rissa tridactyla, Alle alle, Larus hyperboreus y Uria lomvia). Estas especies anidan en la Isla Coburg en el lado oeste y en la Isla Hakluyt en el lado este del Canal de las Aguas del Norte, que se presenta libre de hielos y está situado entre la Isla Ellesmere en Canadá y el noroeste de Groenlandia. Hipotetizamos que las diferencias en la dieta se deberían a que los dos sitios vecinos están sujetos a diferentes condiciones oceanográficas, resultando en un ajuste temporal diferencial en la apertura de las aguas en primavera. El nivel trófico relativo, derivado de los valores de δ15N en los tejidos, fluctuó entre 3.6 para A. alle de la Isla Hakluyt hasta 4.7 para la dieta del final de la época reproductiva de adultos de U. lomvia de la Isla Coburg. En la Isla Coburg, el nivel trófico de individuos de R. tridactyla, U. lomvia y L. hyperboreus que eclosionaron ese año fue mayor que el nivel de los adultos. No encontramos este patrón en la Isla Hakluyt, donde los pichones de todas las especies generalmente ocuparon posiciones tróficas inferiores. Estos resultados sugieren que las presas de niveles tróficos inferiores fueron más importantes para las aves marinas de la Isla Hakluyt, posiblemente debido a una menor disponibilidad de bacalao del Ártico (Boreogadus saida).

Trace Metals (As, Cd, Cu, Fe, and Zn) in Arctic cod, Boreogadus saida, and Selected Zooplankton from Strathcona Sound, Northern Baffin Island

1976 ◽  
Vol 33 (12) ◽  
pp. 2836-2840 ◽  
Author(s):  
Arne Bohn ◽  
R. O. McElroy
Keyword(s):  
Body Weight ◽  
Trace Metals ◽  
Stomach Contents ◽  
Bottom Trawl ◽  
The Arctic ◽  
Baffin Island ◽  
Boreogadus Saida ◽  
Arctic Cod ◽  
Planktonic Copepods ◽  
The Difference

Arctic cod (Boreogadus saida) were captured by bottom trawl at depths of 120–300 m. Zooplankton were obtained by bottom to surface tows from the Arctic cod habitat. Average concentrations of arsenic (As) and zinc (Zn) were higher in Arctic cod fillets than in livers from the same fish; cadmium (Cd) and iron (Fe) concentrations were higher in livers. The difference between copper (Cu) concentrations in muscle and liver was not significant. As and Zn in whole fish, and As in fillets from seven specimens, were positively correlated to body weight. Cu and Fe in whole fish were negatively correlated to body weight, whereas Cd was not related to body weight. Examination of Arctic cod stomach contents indicated that planktonic copepods were important in the diet. Cd levels were 5–8 times higher in the unsorted copepods than in the Arctic cod, whereas As, Cu, Fe, and Zn were higher in the fish than in the copepods.

Suprabenthic crustacean fauna of a denseAmpeliscacommunity from the English Channel

1996 ◽  
Vol 76 (4) ◽  
pp. 909-929 ◽  
Author(s):  
Jean-Claude Dauvin ◽  
Souaad Zouhiri
Keyword(s):  
Atlantic Ocean ◽  
Water Column ◽  
Vertical Migration ◽  
Fine Sand ◽  
Abundant Species ◽  
Sexually Dimorphic ◽  
English Channel ◽  
Free Swimming ◽  
Sea Bottom ◽  
Sea Bed

Ninety-six species (97, 677individuals) were collected over the course of 6 h in five suprabenthic sledge hauls from a very denseAmpeliscafine sand community from the Bay of Morlaix (western English Channel). All the species migrated into the water column at night (98% of the specimens collected in the suprabenthos were found in the night hauls). The 23 most abundant species collected were classified into five groups based on their height within the water column, but two groups predominated: the upper suprabenthic species, abundant at 0–80–145 m above the sea-bed; and the lower suprabenthic species which were abundant only near the sea bottom (-0–1–0–75 m high). Three different patterns of nocturnal vertical migration were distinguished based on the timing of maximum swimming activity: at dusk; at the beginning of the night; or later in the night. Sexually dimorphic patterns of free-swimming behaviour was observed inAmpeliscaand some other species of Amphipoda (Bathyporeia teniupes, Metaphoxusfultoni), and Cumacea (Bodotria pulchella, Pseudocuma longicornis), with many more males than females migrating into the water column at night. Finally, the density of suprabenthic crustaceans in nocturnal hauls was amongst the highest reported from infralittoral or circalittoral suprabenthic studies on other parts of the Atlantic Ocean sampled during spring.

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