A Newly Discovered

Population of Arctic

Char of the

Kigluaik Mountains

of Alaska1

Joseph F. Webb, Retired

BLM Fairbanks, Alaska

Background

Arctic char, Salvelinus alpinus, have

a holarctic distribution and exist as

anadromous, stream resident and

lake resident populations. In Alaska,

the preponderance of evidence

suggests that only lake resident populations occur ( Morrow, 1980 and

Reist, et al. 1997). Until 1987,

Arctic char populations in Alaska

were known only from certain lakes

in the Brooks Range and its northern foothills area, southwestern

Alaska in the Bristol Bay drainage

area, and from south-central

Alaska, the Kenai Peninsula and

Kodiak Island. In 1987, biologists

with the BLM conducted the first

fishery inventories of lakes and

streams in the Kigluaik Mountains,

Alaska, and documented the presence of char, Salvelinus sp. in several

area lakes. Early objectives of this

project were to document fish presence in Kigluaik Mountain lakes and

to determine whether char were S.

alpinus or S. malma. Later efforts

sought to determine to which subspecies did the char belong.

The Kigluaik Mountains are on the

Seward Peninsula, approximately

60 kilometers north of Nome,

Alaska, at 66 degrees north latitude

and 165 degrees west longitude.

The mountain range extends for

about 72 kilometers east to west

and 20 kilometers north and

south. Peaks and ridge lines rise

sharply from near sea level to elevations of 1433 meters. Tundra

dominates the vegetation. The

Kigluaik Mountains are treeless

except for small willows (Salix sp.).

Within the mountains are approximately 50 glacially formed lakes

and ponds ranging in size from a

few hectares to several hundred

hectares. Many of these lakes have

barriers to fish entry because of

avalanche dikes or waterfalls. The

largest recorded lake containing

char is approximately 115 hectares.

Methods

The first fish population sampling

of the Kigluaik lakes was conducted in 1987. Since that point, fish

populations have been investigated

in 1992, 1995, 1996, and 1997. In

1987, 21 of approximately 50 lakes

in the area were visually examined

by use of aircraft to determine

their likelihood of supporting fish.

Those lakes believed likely to contain fish were sampled with variable

mesh monofilament gill nets or

hook and line. The following data

was usually recorded from each

specimen at the time of capture:

total and fork length, weight, sex,

and state of maturity. Pyloric caeca

and gill rakers were removed for

future analysis.

The number of pyloric caeca and

gill rakers are widely used characteristics for distinguishing between

S. alpinus and the more common

S. malma. Although it must be stated that these characteristics are not

absolute but rather a range of values

(Morrow 1980, Scott and Crossman

1973, and McPhail 1961).

Discussion

Six lakes of 21 observed by air in

1987 were thought likely to support fish. The six lakes were fished

with monofilament gill nets. Char,

Salvelinus sp. were the only species

found. Gill raker counts for these

fish fit into the range given by

Morrow (1980) for both S. alpinus

and S. malma and so were of no

value for precise classification.

Mean pyloric caeca number was

within Morrow’s range of values for

S. alpinus only. In 1996, samples,

gill rakers, and pyloric caeca numbers were within the ranges for

both S. alpinus and S. malma.

However, pyloric caeca counts were

in the extreme upper range given

by Morrow. At this point, it seems

that gill raker counts may be of little value as a diagnostic feature for

determining speciation in Kigluaik

Mountain char while pyloric caeca

counts may be of some value in

helping to separate S. malma from

S. alpinus.

Comparative observations of caudal

fin shape between stream and lake

resident char revealed that lake char

had fins that were distinctly forked

at the posterior margins with rather

pointed tips, whereas the fins of

stream char were only slightly

indented and had rounded tips.

Observations of color patterns,

markings, and body shape revealed

some quite interesting findings.

Crater Lake was the only lake in

which adult fish exhibited a typical,

non-neotenic adult color pattern: a

pale silvery gray on the dorsal

surface and on the sides above the

lateral line with distinct orange to

pink ventral coloring and with

prominent pink spots on the side

primarily below the lateral line.

The Falls Creek Lake specimens

and those from other lakes collected during the initial 1987

inventories, and in subsequent

years, exhibited a high degree of

neoteny. Neoteny is a fairly common phenomenon among different

populations of S. alpinus and S.

malma, especially showing up in

populations where sexual maturity

is reached at a comparatively small

size but at an old age. Thirty-seven

char collected from five lakes in

1987 ranged from 183 to 574 mm

fork length and were from 7 to 12

years old. Crater Lake was the only

lake where char longer than 400

mm were found.

Inventories of lakes since 1987

have primarily collected specimens

RESOURCE NOTES

NO. 21 DATE 06/27/00

Range

Wildlife Biology

1

adopted from Webb, Joseph F. 1999. Article Char of the Kigluaik Mountains of Alaska, in the Proceedings

of the Eighth and Ninth International Society of Arctic Char Fanatics (ISACF) Workshop on Arctic Char 1996 and

1998. Frederick W. Kircheis, ed. Information Series Number 7.
for genetic studies currently in

progress. In 1992 five specimens

were taken from Falls Creek Lake

for potential DNA genetic analysis.

In 1995 another visit was made

where nine specimens were taken

for genetic study. The nine specimens collected in 1995 had been

feeding heavily on chironomid and

trichopteran larvae. Two individuals had fed on two other fish: one

appeared to be a small char and

the other char had eaten a slimy

sculpin, Cottus cognatus. This discovery was the first finding of a

non- char species from Fall Creek

Lake. Specimens for genetic testing

were again collected in both 1996

and 1997.

Initial results indicate these fish

appear to be genetically distinct

from other populations of S. alpinus and were the first Arctic char

collected from this area of Alaska.

Preliminary genetic analysis using

ribosomal DNA first internal spacer region was different from other

S. alpinus populations that were

available for comparison. Further

genetic analysis indicated that the

populations from the two lakes

(Crater and Fall Creek) are also

different from each other.

Conclusion

The discoveries made thus far

include the following: heretofore

unknown populations of Salvelinus

alpinus and S. malma have been discovered; some of these populations

appear presently to be reproductively

isolated from other populations outside the Kigluaik Mountains and

from each other; the char from

Falls Creek Lake retain juvenile

parr marks at an unusually large

size; the char from Crater Lake are

the only populations having adults

with normal adult markings and

coloration, and the pink spots on

these adult char are confined primarily below the lateral line; all

lakes in the Kigluaik Mountains

that appear to be deep enough to

contain fish apparently do not contain fish (i.e., some of those lakes

that have avalanche dikes or waterfalls near their outlets contain fish

and some apparently do not).

To understand what may have

happened to isolate fish in these

lakes, one must go back in time

approximately 18,000 years to the

last emergence of Beringia, the lowland mass between Asia and North

America which has been periodically exposed and flooded depending

on the extent of continental glaciation. The drainage patterns of

rivers that crossed Beringia have

been discovered by marine geologists. Some modern Alaskan rivers

that now empty into the sea were

once joined to other rivers that

were connected as headwaters

common to the Beringia river

system, so that direct freshwater

access was available to the opposite

side of the Bering Strait. Throughout

the Pleistocene, the ability of freshwater fish to traverse Beringia has

been limited by barriers of sea

water or glacial mass. However,

with species having the ability to

become anadromous, sea water did

not represent a significant barrier

to distribution. There must have

been a “window of time” when

an Atlantic/Arctic Basin endemic

(S. alpinus) could invade areas on

the Seward Peninsula before Pacific

endemic species (S. malma) could

invade.

In addition to the Beringian phenomenon, the glaciation of the

Kigluaik Mountains was a simultaneous phenomenon that existed

separately from the great continental glaciers. Kigluaik Mountain

glacial systems existed in varied size

and location due to factors of

slope, elevation, and aspect. The

lake basins that resulted from

glaciation and that filled with

water at the glaciers’ retreat were

created during different times

because of these varying topographic and microclimate conditions. It

is likely that S. alpinus and not S.

malma (a stream inhabitant) would

have been the species successful in

establishing populations in the

newly created lake habitat left by

the retreating mountain glaciers.

Later, as the continental glaciers

retreated, Arctic char populations

remained only in the highland

lakes where they had established

themselves and remain today as

remnant populations isolated by

avalanche dike or waterfall barriers.

For more detailed information, see

the original articles published as:

Webb, Joseph F. 1999. Arctic

Char of the Kigluaik Mountains

of Alaska, in the Proceedings of

the Eighth and Ninth International

Society of Arctic Char Fanatics

(ISACF) Workshop on Arctic Char

1996 and 1998. Frederick W.

Kircheis, ed. Information Series

Number 7.

For information on how to reach

Mr. Webb, contact:

Bruce M. Durtsche,

Wildlife Biologist, NSTC

Building 50, Denver Federal

Center, PO Box 25047

Denver, CO, 80225-0047

phone (303) 236-6310

fax (303) 236-3508

email bdurtsch@blm.gov

Range

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Information in this Resource Note is based on the opinion and

experience of the author and has not been peer-reviewed. Conclusions

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