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Dolly Varden
Blue dots show rearing areas.
Blue crosshatching shows coastal feeding and migration areas.
Dolly Varden have adapted to the rigors of the climatic and physical environment of the
arctic. For almost
nine months of the year, the fish are confined to relatively small reaches of stream and river
channels for overwintering. The available overwintering habitat is critical to their survival
and is considered to be the major limiting factor for populations of arctic fishes. After
break-up, which begins in late May or early June, the distribution of Dolly Varden expands to
streams and river channels that were previously frozen, and to the nearshore coastal waters for
feeding and rearing. Unobstructed migration to feeding areas is important if Dolly Varden are
to make the best use of the limited open water season in the Arctic. During this short period,
the fish grow, accumulating fats to aid in their survival through the winter.
Juvenile Dolly Varden remain in the rivers for several years. Between the ages of two and four
years, they complete their transformation to smolt. The anadromous fish then migrate to nearshore coastal waters where they spend the summer
months feeding on macroinvertebrates. Dolly Varden maintain a strong fidelity to overwintering
and spawning areas in the rivers they return to in late August through September. Spawning may
occur from August through late September. Overwintering and spawning areas are associated
with springs which flow year round. Dolly Varden generally mature after five years.
References
Craig P. 1984. Fish use of coastal waters of the Alaskan Beaufort Sea: a review.
Transactions of the American Fisheries Society 113:265-282.
Craig, P. 1989. An introduction to anadromous fish in the Alaskan Arctic. In D.W. Norton,
editor. Research advances on anadromous fish in arctic Alaska and Canada. Biological papers
of the University of Alaska Number 24:27-54.
McCart, P. 1980. A review of the systematics and ecology of Arctic char, Salvelinus alpinus,
in the western Arctic. Canadian Technical Report of Fisheries and Aquatic Science Number 935.
Underwood, T.J., J.A. Gordon, M.J. Millard, L.A. Thorpe, and B.M. Osborne. 1995.
Characteristics of selected fish populations of Arctic National Wildlife Refuge coastal
waters, final report, 1988-1991. U.S. Fish and Wildlife Service, Fairbanks Fishery Resource
Office, Alaska Fisheries Technical Report Number 28, Fairbanks, Alaska.
Wiswar, D.W. 1992. Summer distribution of arctic fishes in the Okpilak, Akutoktak,
Katakturuk, and Jago rivers, Arctic National Wildlife Refuge, Alaska, 1990. U.S. Fish and
Wildlife Service, Alaska Fisheries Technical Report Number 17, Fairbanks, Alaska.
Wiswar, D.W. 1994. Summer Distribution of Arctic Fishes in the 1002 Area of the Arctic
National Wildlife Refuge, Alaska, 1991 with emphasis on selected lakes, tundra streams, and
the Sadlerochit River drainage. U.S. Fish and Wildlife Service, Alaska Fisheries Technical
Report Number 27, Fairbanks, Alaska.
September 12, 2008
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