Life history and essential habitats of humpback whitefish in Lake Clark National Park, Kvichak River watershed, Alaska
(continued)

DISCUSSION

Although humpback whitefish are the second most important subsistence fish species harvested in the Kvichak River watershed, few data are available to assist managers in evaluating a reported recent decline in this species’ abundance.  Initial research on humpback whitefish in Lake Clark National Park began in 2005, and indicates they are both attracted to and derive nutrients from anadromous sockeye salmon.  We capitalized on this behavior and were able to easily sample humpback whitefish with seines and gillnets in areas baited with salmon eggs.  Ice fishing was also found to be a viable, but slow capture method.

Similar to results obtained from Canadian studies of lake whitefish (Barnes and Power 1984), our age estimates of humpback whitefish were the same from both scales and otoliths for the first three years of life, after which, age estimates from these two structures began to vary.  The difficultly in obtaining accurate age estimates suggests an age validation study would be useful to this and other similar studies.  In Lake Clark this could be accomplished by marking and recapturing humpback whitefish of various sizes in a small system such as the Pickeral Lakes, assuming they exhibit site fidelity and that a wide range of ages could be marked. 

Size distribution for the population based on samples obtained from seines, variable mesh gillnets and hook and line fishing indicate a bimodal frequency distribution.  This type of distribution is similar to that observed for other whitefish species and lake trout in Arctic systems of Canada (Power 1984).  Our growth equations (Figure 8) indicate rapid growth until age 4 – 7, which is likely when individuals become sexually mature which would slow growth rates.  The lack of individuals of intermediate sizes could be due to differences in year class strength, selection by the subsistence fishery or predators.  After fish reach a size of ≥ 380 mm, predation likely declines and mortality in the population may stabilize at a low level for the rest of the life span. 

The lack of a strong Sr spike in the 10 otoliths analyzed for anadromy suggests Lake Clark whitefish either remain in freshwater throughout their life, or that they use estuarine areas with very low salinities.  The high variation observed in the Sr signal of some fish may be due to spending time in a low salinity estuary, extensive vertical movements within freshwater, or feeding on anadromous sockeye salmon carcasses and eggs.  Further study is needed to tease out potential causal factors.  The radio telemetry work planned for 2006 may allow us to determine whether some Lake Clark whitefish are anadromous.

ACKNOWLEDGEMENTS

REFERENCES

Alt, K. T.  1979.  Contributions to the life history of the humpback whitefish in Alaska.  Transactions of the American Fisheries Society 108:156-160.

Alt, K. T., and D. R. Kogl.  1973.  Notes on the whitefish of the Coville River, Alaska.  Journal Fisheries Research Board of Canada 30(4):554-556.

Anderson, J. W. 1969.  Bathymetric measurements of Iliamna Lake and Lake Clark, Alaska.  University of Washington, Fisheries Research Institute Circular No. 69-17.

Anras, M. L. B., P. M. Cooley, R. A. Bodaly, L. Anras, and R. J. P. Fudge.  1999.  Movement and habitat use by lake whitefish during spawning in a boreal lake: integrating acoustic telemetry and geographic information systems.  Transactions of the American Fisheries Society 128:939-952.

Barnes, M. A. and G. Power.  1984.  A comparison of otolith and scale ages for western Labrador lake whitefish (Corogonis clupeaformes).

Bond, W. A. and R. N. Erickson.  1985.  Life history studies of anadromous coregonid fishes in two freshwater lake systems on the Tuktoyaktuk Peninsula, Northwest Territories.  Can. Tech. Rep. Fish. Aquat. Sci.  1336.  61 p.

Brabets, T. P.  2002.  Water quality of the Tlikakila River and five major tributaries to Lake Clark, Lake Clark National Park and Preserve, Alaska, 1999-2001.  U.S. Geological Survey Water Resources Investigations Report 02-4127.

Brown, R. J.  2000.  Migratory patterns of Yukon River inconnu as determined with otolith microchemistry and radio telemetry.  Master’s Thesis, University of Alaska Fairbanks, Fairbanks, Alaska.

Brown, R. J., C. Lunderstadt, and B. Schulz.  2002.  Movement patterns of radio-tagged adult humpback whitefish in the upper Tanana River Drainage.  Alaska Fisheries Data Series Number 2002-1.

Brown, R .J.  2006.  Humpback whitefish of the upper Tanana River drainage.  Alaska Fisheries Technical Report No. 90.  U.S. Fish and Wildlife service, Fairbanks, Alaska.

Campana, S. E., S. R. Thorrold, C. M. Jones, D. Gtinther, M. Tubrett., H Longerich, S. Jackson, N. M. Halden, J. M. Kalish, P. Piccoli, H. de Pontual, H. Troadec, J. Panfili, D. H. Secor, K. P. Severin, S. H. Sie, R. Thresher, W. J. Teesdale, and J. L. Campbell.  1997.  Comparison of accuracy, precision, and sensitivity in elemental assays of fish otoliths using the electron microprobe, proton-induced x-ray emission, and laser ablation inductively coupled plasma mass spectrometry.  Canadian Journal of Fisheries and Aquatic Sciences 54:2068-2079.

Chilton, D. E. and R. J. Beamish.  1982.  Age determination methods for fishes studied by the groundfish program at the Pacific Biological Station.  Canadian Special Publication of Fisheries and Aquatic Sciences 60:1-102.

Fall, J. A., M. B. Chythlook, J. C. Schichnes, and J. M. Morris.  1996.  An overview of the harvest and use of freshwater fish by the communities of the Bristol Bay region, southwest Alaska.  Alaska Department of Fish and Game, Division of Subsistence, Technical Paper Series.  Technical Paper No. 166, 171 p.

Farrell, J. and S.E. Campana.  1996.  Regulation of calcium and strontium deposition on the otoliths of juvenile tilapia, Oreochromis niloticus.  Comparative Biochemistry and Physiology 115: 103-109.

Fleming, D. F.  1996.  Stock assessment and life history studies of whitefish in the Chatanika River during 1994 and 1995.  Alaska Department of Fish and Game, Fishery Data Series No. 96-19.

Fleming, D. F.  1999.  Stock monitoring of whitefish in the Chatanika River during 1998.  Alaska Department of Fish and Game, Fishery Data Series No. 99-18.

Fowler, A. J., S. E. Campana, C. M. Jones, and S. R. Thorrold.  1995a.  Experimental assessment of the effect of temperature and salinity on elemental composition of otoliths using solution-based ICPMS.  Canadian Journal of Fisheries Aquatic Sciences 52: 1421-1430.

Fowler, A. J., S. E. Campana, C. M. Jones, and S. R. Thorrold.  1995b.  Experimental assessment of the effect of temperature and salinity on elemental composition of otoliths using laser ablation ICPMS. Canadian Journal of Fisheries Aquatic Sciences 52: 1431-1441.

Goldstein, J. I., D. E. Newbury, D. C. Joy, C. E. Lyman, P. Echlin, E. Lifshin, L. Sawyer, and J. R. Michael.  2003.  Scanning electron microscopy and x-ray microanalysis, Third edition, Kluwer Academic/Plenum Publishers, New York, New York.

Howland, K. L., M. Gendron, W. M. Tonn, and R. F. Tallman. 2004. Age determination of a long-lived cordgonid from the Canadian North: comparison of otoliths, fin rays and scales in inconnu (Stenodus leucichthys).  Annales Zoologici Fennici 41: 205-214.

Mecklenburg, C. W., T. A. Mecklenburg, and L.K. Thorsteinson.  2002.  Fishes of Alaska.
American Fisheries Society, Bethesda Maryland.

Mills, K. H. and R. J. Beamish.  1980.  Comparison of fin-ray and scale age determination for lake whitefish (Coregonus clupeaformis) and their implications for estimates of growth and annual survival.  Canadian Journal of Fisheries and Aquatic Sciences 37:534-544.

Morris, J. M.  1986.  Subsistence production and exchange in the Iliamna Lake region, southwest Alaska, 1982-1983.  Alaska Department of Fish and Game, Division of Subsistence, Technical Paper Series.  Technical Paper No. 136, 187 p.

Morrow, J. E.  1980.  The freshwater fishes of Alaska.  Alaska Northwest Publishing Company, Anchorage, Alaska.

Mugiya, Y. and S. Tanaka.  1995.  Incorporation of water-borne strontium into otoliths and its turnover in the goldfish Carassius auratus: effects of strontium concentrations, temperature, and 17b-estradiol.  Fisheries Science 61: 29–35.

Potts, P. J.  1987.  A handbook of silicate rock analysis.  Chapman and Hall, New York, New York.

Reed, S. J. B.  1997.  Electron microprobe analysis, Second edition.  Cambridge University Press, New York, New York.

Reist, J. D., and W. A. Bond.  1988.  Life history characteristics of migratory coregonids of the lower Mackenzie River, Northwest Territories, Canada.  Finnish Fisheries Research 9: 133-1444.

Russell, R.  1980.  A fisheries inventory of waters in the Lake Clark National Monument area.  Alaska Department of Fish and Game.

Secor, D. H., A, Henderson-Arzapalo, and P. M. Piccoli,  1995.  Can otolith microchemistry chart patterns of migration and habitat utilization in anadromous fishes?  Journal of Experimental Marine Biology and Ecology 192: 15–33.

Stickman, K. A., A Balluta, M. McBurney, and D. Young.  2003.  K’ezghlegh Nondalton traditional ecological knowledge of freshwater fish.  USFWS Office of Subsistence Management, Fisheries Resource Monitoring Program, Final Program, Final Report.

Westing C., S. Morstad, K.A. Weiland, T. Sands, L. Fair, F. West, and C. Brazil. 2005. Annual Management Report 2004, Bristol Bay Area. Alaska Department of Fish and Game, Fishery Management Report No. 05-41, Anchorage. 130 pp.

Wilkens, A. X.  2002.  The limnology of Lake Clark, Alaska.  Masters thesis.  Univerisity of Alaska Fairbanks.

Woody, C.A.  2004.  Population monitoring of sockeye salmon from Lake Clark and the Tazimina River, Kvichak River watershed, Bristol Bay, Alaska, 2000-2003.  Final Report 01-095.  U.S. Fish and Wildlife Service Office of Subsistence Management. Anchorage, Alaska.

Young, D. B. and C. A. Woody.  2006.  Lake Clark sockeye salmon escapement and population monitoring.  Annual Report for Study FIS 05-402.  U.S. Fish and Wildlife Service Office of Subsistence Management. Anchorage, Alaska.

Zimmerman, C. E. and G. H. Reeves.  2000.  Population structure of sympatric anadromous and nonanadromous Oncorhynchus mykiss: evidence from spawning surveys and otolith microchemistry.  Canadian Journal of Fisheries and Aquatic Sciences 57:2152-2162.

Appendix I.  Example of the humpback whitefish ACCESS database documenting sampling locations, general habitat type and whether humpback whitefish were captured in that habitat.