scholarly journals Four Hundred and Fifty-Year-Old Skeletal Remains of Atlantic Cod (Gadus morhua) Found on Multiyear Ice in High Arctic Canada

ARCTIC ◽  
2018 ◽  
Vol 71 (1) ◽  
Author(s):  
Richard E. Crawford ◽  
Elizabeth Striano ◽  
Peter Amarualik Sr. ◽  
Nancy Amarualik ◽  
Steven L. Cumbaa ◽  
...  
2011 ◽  
Vol 89 (5) ◽  
pp. 419-434 ◽  
Author(s):  
M. Festa-Bianchet ◽  
J.C. Ray ◽  
S. Boutin ◽  
S.D. Côté ◽  
A. Gunn

Caribou ( Rangifer tarandus (L., 1758)) play a central role in the ecology and culture of much of Canada, where they were once the most abundant cervid. Most populations are currently declining, and some face extirpation. In southern Canada, caribou range has retreated considerably over the past century. The ultimate reason for their decline is habitat alterations by industrial activities. The proximate causes are predation and, to a lesser extent, overharvest. The most southerly populations of “Mountain” caribou are at imminent risk of extirpation. Mountain caribou are threatened by similar industrial activities as Boreal caribou, and face increasing harassment from motorized winter recreational activities. Most populations of “Migratory Tundra” caribou are currently declining. Although these caribou fluctuate in abundance over decades, changing harvest technologies, climate change, increasing industrial development and human presence in the North raise doubts over whether recent declines will be followed by recoveries. The Peary caribou ( Rangifer tarandus pearyi J.A. Allen, 1902), a distinct subspecies endemic to Canada’s High Arctic, has suffered drastic declines caused by severe weather, hunting and predation. It faces an increasing threat from climate change. While some questions remain about the reasons for the decline of Migratory Tundra caribou, research has clearly identified several threats to the persistence of “Boreal”, Mountain, and Peary caribou. Scientific knowledge, however, has neither effectively influenced policies nor galvanized public opinion sufficiently to push governments into effective actions. The persistence of many caribou populations appears incompatible with the ongoing pace of industrial development.


Polar Biology ◽  
2017 ◽  
Vol 40 (10) ◽  
pp. 2105-2111 ◽  
Author(s):  
Randi B. Ingvaldsen ◽  
Harald Gjøsæter ◽  
Egil Ona ◽  
Kathrine Michalsen

2014 ◽  
Vol 514 ◽  
pp. 217-229 ◽  
Author(s):  
HY Wang ◽  
LW Botsford ◽  
JW White ◽  
MJ Fogarty ◽  
F Juanes ◽  
...  

2009 ◽  
Vol 36 (4) ◽  
pp. 883-891 ◽  
Author(s):  
Carlo C. Lazado ◽  
Christopher Marlowe A. Caipang ◽  
Sanchala Gallage ◽  
Monica F. Brinchmann ◽  
Viswanath Kiron

Polar Biology ◽  
2021 ◽  
Author(s):  
Hiroko K. Solvang ◽  
Tore Haug ◽  
Tor Knutsen ◽  
Harald Gjøsæter ◽  
Bjarte Bogstad ◽  
...  

AbstractRecent warming in the Barents Sea has led to changes in the spatial distribution of both zooplankton and fish, with boreal communities expanding northwards. A similar northward expansion has been observed in several rorqual species that migrate into northern waters to take advantage of high summer productivity, hence feeding opportunities. Based on ecosystem surveys conducted during August–September in 2014–2017, we investigated the spatial associations among the three rorqual species of blue, fin, and common minke whales, the predatory fish Atlantic cod, and their main prey groups (zooplankton, 0-group fish, Atlantic cod, and capelin) in Arctic Ocean waters to the west and north of Svalbard. During the surveys, whale sightings were recorded by dedicated whale observers on the bridge of the vessel, whereas the distribution and abundance of cod and prey species were assessed using trawling and acoustic methods. Based on existing knowledge on the dive habits of these rorquals, we divided our analyses into two depth regions: the upper 200 m of the water column and waters below 200 m. Since humpback whales were absent in the area in 2016 and 2017, they were not included in the subsequent analyses of spatial association. No association or spatial overlap between fin and blue whales and any of the prey species investigated was found, while associations and overlaps were found between minke whales and zooplankton/0-group fish in the upper 200 m and between minke whales and Atlantic cod at depths below 200 m. A prey detection range of more than 10 km was suggested for minke whales in the upper water layers.


Author(s):  
Sayyed Mohammad Hadi Alavi ◽  
Azadeh Hatef ◽  
Ian A.E. Butts ◽  
Olga Bondarenko ◽  
Jacky Cosson ◽  
...  

2000 ◽  
Vol 57 (4) ◽  
pp. 826-836 ◽  
Author(s):  
Jean-Denis Dutil ◽  
Yvan Lambert

The extent of energy depletion was assessed in Atlantic cod (Gadus morhua) in spring and early summer (1993-1995) to assess relationships between poor condition and natural mortality. Several indices of condition were compared in wild fish in the northern Gulf of St. Lawrence and in fish exposed to a prolonged period of starvation in laboratory experiments. Discriminant analyses classified only a small fraction of the wild fish as similar to cod that did not survive and a much larger fraction as similar to cod that survived starvation. This percentage increased from April to May and peaked in June 1993 and 1994. Condition factor and muscle somatic index allowed a clear distinction between live and dead fish. Muscle lactate dehydrogenase activity suggested that cod had experienced a period of negative growth early in 1993, 1994, and 1995. Fish classified as similar to starved individuals were characterized by a higher gonad to liver mass ratio than others. Reproduction may have a negative impact on survival not only in spring but also later into summer, as some individuals were found not to have recovered by late summer. This study shows that natural mortality from poor condition contributed to lower production in the early 1990s.


2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Andrea Bagi ◽  
Even Sannes Riiser ◽  
Hilde Steine Molland ◽  
Bastiaan Star ◽  
Thomas H. A. Haverkamp ◽  
...  

2010 ◽  
Vol 70 (5) ◽  
pp. 383-394 ◽  
Author(s):  
Sonnich Meier ◽  
H. Craig Morton ◽  
Gunnar Nyhammer ◽  
Bjørn Einar Grøsvik ◽  
Valeri Makhotin ◽  
...  

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