Stephen Riley


My work focuses on the ecology of fish communities in the Great Lakes, particularly in Lake Huron.  I conduct work on the ecology and dynamics of the deepwater demersal fish community in Lake Huron, and also lake trout ecology.  I have been involved in research on thiamine deficiency in lake trout, and also on botulism in Lake Michigan.  I am currently the editor of the North American Journal of Fisheries Management and a member of the Board of Technical Experts of the Great Lakes Fishery Commission.


Journal articles

Riley, S.C., A.T. Bielak, and G. Power. 1984. The Atlantic salmon stock of the Grand Watshishou River (Quebec): a historical perspective. Naturaliste Canadien 111:219-228.


Riley, S.C. and G. Power. 1987. Age at maturity in landlocked and anadromous Atlantic salmon parr from two Quebec Rivers. Environmental Biology of Fishes 19:223-228.


Adams, N.J., D.R. Barton, R.A. Cunjak, G. Power, and S.C. Riley. 1988. Diel patterns of activity and substrate preference in young Arctic char of the Koroc River, northern Quebec. Canadian Journal of Zoology 66:2500-2502.


Riley, S.C., G. Power, and P.E. Ihssen. 1989. Meristic and morphometric variation in parr of Ouananiche and anadromous Atlantic salmon from rivers along the North Shore of the Gulf of St. Lawrence. Transactions of the American Fisheries Society 118:515-522.


Bestgen, K.R., K.D. Fausch, and S.C. Riley. 1991. Rediscovery of a relict southern population of Lake Chub, Couesius plumbeus, in Colorado. Southwestern Naturalist 36:125-127.


Riley, S.C., and K.D. Fausch. 1992. Underestimation of trout population size by maximum likelihood removal estimates in small streams. North American Journal of Fisheries Management 12:768-776.


Riley, S.C., K.D. Fausch, and C. Gowan. 1992. Movement of brook trout (Salvelinus fontinalis) in four small subalpine streams in northern Colorado. Ecology of Freshwater Fish 1:112-122.


Riley, S.C., R.L. Haedrich, and R.J. Gibson. 1993. Negative bias of removal estimates of Atlantic salmon parr abundance in relation to stream size. Journal of Freshwater Ecology 8:97-101.


Gowan, C., M.K. Young, K.D. Fausch, and S.C. Riley. 1994. Restricted movement in stream salmonids: a paradigm lost? Canadian Journal of Fisheries and Aquatic Sciences 51:2626-2637.


Riley, S. C., and K. D. Fausch. 1995. Trout population response to habitat enhancement in six northern Colorado streams. Canadian Journal of Fisheries and Aquatic Sciences 52:34-53.


Fausch, K.D., C. Gowan, A. Richmond, and S.C. Riley. 1995. The role of dispersal in trout population response to habitat formed by large woody debris in Colorado mountain streams. Bulletin Francais de la Peche et de Pisciculture, 337/338/339:179-190.


Kocovsky, P.M., C. Gowan, K.D. Fausch, and S.C. Riley. 1997. Spinal injury rates in three wild trout populations in Colorado after eight years of backpack electrofishing. North American Journal of Fisheries Management 17:308-313.


Latterell, J.J., K.D. Fausch, C. Gowan, and S.C. Riley. 1998. Relationship of trout recruitment to snowmelt runoff flows and adult trout abundance in six Colorado mountain streams. Rivers 6:240-250.


Bult, T.P., S.C. Riley, R.L. Haedrich, R. J. Gibson, and J. Heggenes. 1999. Density-dependent habitat selection by juvenile Atlantic salmon (Salmo salar L.) in experimental riverine habitats. Canadian Journal of Fisheries and Aquatic Sciences 56:1298-1306.


Berejikian, B.A., E.P. Tezak, S.C. Riley, and A. LaRae. 2001. Competitive ability and social behaviour of juvenile steelhead reared in enriched and conventional hatchery tanks and a stream environment. Journal of Fish Biology 60:600-613.


Riley, S.C., H.J. Fuss, and L.L. LeClair. 2004. Ecological effects of hatchery-reared juvenile chinook and coho salmon on wild salmonids in two Washington streams. North American Journal of Fisheries Management 24:506-517.


Riley, S.C., C.P. Tatara and J.A. Scheurer.  2005. Aggression and feeding of hatchery-reared and naturally reared steelhead (Oncorhynchus mykiss) fry in a laboratory flume and a comparison with observations in natural streams.  Canadian Journal of Fisheries and Aquatic Sciences 62: 1400-1409.


Savino, J.F., S.C. Riley, and M.J. Holuszko.  2007.  Activity, aggression and habitat use of ruffe (Gymnocephalus cernuus) and round goby (Neogobius melanostomus) under laboratory conditions.  Journal of Great Lakes Research 33: 326-334.


Riley, S.C., J.X. He, J.E. Johnson, T.P. O’Brien, and J.S. Schaeffer.  2007.  Evidence of widespread natural reproduction by lake trout Salvelinus namaycush in the Michigan waters of Lake Huron.  J. Great Lakes. Res. 33: 917-921.


Riley, S.C., and A.N. Evans.  2008.  Phylogenetic and ecological characteristics associated with thiaminase activity in Laurentian Great Lakes fishes. Transactions of the American Fisheries Society 137: 147-157.


Tatara, C.P., S.C. Riley, and J.A. Scheurer.  2008.  Environmental enrichment in steelhead (Oncorhynchus mykiss) hatcheries: field evaluation of aggression, foraging and territoriality in natural and hatchery fry.  Canadian Journal of Fisheries and Aquatic Sciences 65: 744-753.


Riley, S.C., K.R. Munkittrick, A.N. Evans, and C.C. Krueger.  2008.  Understanding the ecology of disease in Great Lakes fish populations.  Aquatic Ecosystem Health and Management 11: 321-334.


Riley, S.C., E.F. Roseman, S.J. Nichols, T.P. O’Brien, C.S. Kiley, and J.S. Schaeffer.  2008.  Deepwater demersal fish community collapse in Lake Huron.  Transactions of the American Fisheries Society 137: 1879-1890. 


Kiffney, P.M., G.R. Pess, J.H. Anderson, P. Faulds, K. Burton, and S.C. Riley.  2009.  Changes in fish communities following recolonization of the Cedar River, WA, USA by Pacific salmon after 103 years of local extirpation.  River Research and Applications 25: 438-452.


Roseman, E.F., and S.C. Riley. 2009. Biomass of deepwater demersal forage fishes in Lake Huron, 1994-2007: implications for offshore predators.  Aquatic Ecosystem Health and Management 12: 29-36.


Tillitt, D.E., S.C. Riley, A.N. Evans, S.J. Nichols, J.L. Zajicek, J. Rinchard, C.A. Richter, and C.C. Krueger.  2009.  Dreissenid mussels from the Great Lakes contain elevated thiaminase activity.  Journal of Great Lakes Research 35: 309-312.


Tatara, C.P., S.C. Riley, and J.A. Scheurer.  2009.  Growth, survival and habitat use of naturally reared and hatchery steelhead fry in streams: effects of an enriched hatchery rearing environment.  Transactions of the American Fisheries Society 138: 441-457.


Roseman, E.F., W. Stott, T.P. O’Brien, and S.C. Riley. 2009. Heritage strain and diet of wild young of year and yearling lake trout in the main basin of Lake Huron. Journal of Great Lakes Research 35:620-626.


Riley, S.C., C.P. Tatara, B.A. Berejikian and T.A. Flagg. 2009.  Behavior of steelhead fry in a laboratory stream is affected by fish density but not rearing environment. North American Journal of Fisheries Management 29: 1806-1818.


Bunnell, D.B., J.V. Adams, O.T. Gorman, C.P. Madenjian, S.C. Riley, E.F. Roseman, and J.S. Schaeffer.  2010.  Population synchrony of a native fish across three Laurentian Great Lakes: evaluating the effects of dispersal and climate.  Oecologia 162: 641-651.


Riley, S.C., and J.V. Adams.  2010.  Long-term trends in habitat use of offshore demersal fishes in western Lake Huron suggest large-scale ecosystem change.  Transactions of the American Fisheries Society 139: 1322-1334.


Lafrancois, B.M., S.C. Riley, D.S. Blehert, and A. Ballmann. 2011. Links between type-E botulism outbreaks, lake levels, and surface water temperatures in Lake Michigan. Journal of Great Lakes Research.37: 86-91.


Tatara, C. P., S. C. Riley, and B. A. Berejikian.  2011.  Effects of hatchery fish density on emigration, growth, survival, and predation risk of natural steelhead fry in an experimental stream channel.  North American Journal of Fisheries Management 31: 224-235. 


Riley, S.C., J. Rinchard, M. P. Ebener, D. E. Tillitt, K. R. Munkittrick, J. L. Parrott, and J. D. Allen.  2011.  Thiamine concentrations in lake whitefish eggs from the upper Great Lakes are related to maternal diet.  Journal of Great Lakes Research 37: 732-737. 


Riley, S. C., J. Rinchard, D. C. Honeyfield, A. N. Evans, and L. Begnoche.  2011.  Increasing thiamine concentrations in lake trout eggs from lakes Huron and Michigan coincide with low alewife abundance.  North American Journal of Fisheries Management 31: 1052-1064.


He, J. X., M. P. Ebener, S. C. Riley, A. Cottrill, A. Kowalski, S. Koproski, L. Mohr, and J. E. Johnson.  2012.  Lake trout status in the main basin of Lake Huron, 1973-2010.  North American Journal of Fisheries Management 32: 402-412.


Richter, C. A., A. N. Evans, M. K. Wright-Osment, J. L. Zajicek, S. A. Heppell, S. C. Riley, C. C. Krueger, and D. E. Tillitt.  2012.  Paenibacillus thiaminolyticus is not the cause of thiamine deficiency impeding lake trout recruitment in the Great Lakes.  Canadian Journal of Fisheries and Aquatic Sciences 69: 1056-1064.    


Dunlop, E. S., and S. C. Riley.  In review.  The contribution of cold winter temperatures to the 2003 alewife population collapse in Lake Huron.   Journal of Great Lakes Research.


Collingsworth, P. D.,  D. B. Bunnell, C. P. Madenjian and S. C. Riley.  In review.  Comparative recruitment dynamics of alewife (Alosa pseudoharengus) and bloater Coregonus hoyi) in lakes Michigan and Huron.  Canadian Journal of Fisheries and Aquatic Sciences.


Bunnell, D. B., R. P. Barbiero, S. A. Ludsin, C. P. Madenjian, G. J. Warren, D. M. Dolan, T. O. Brenden, R. Briland, O. T. Gorman, J. X. He, T. H. Johengen, B. F. Lantry, T. F. Nalepa, S. C. Riley, C. M. Riseng, T. J. Treska, I. Tsehaye, D. M. Warner, M. G. Walsh, and B. C. Weidel.  In review. Evaluating bottom-up and top-down regulation in Great Lakes food webs.  Bioscience.


Selected Reports


Riley, S.C., and G. Power. 1987. Potential interactions between Atlantic salmon (Salmo salar) and other fishes in Lake Ontario. Lake Ontario Atlantic Salmon Research Workshop, Guelph, Ontario.


Riley, S.C. 1992. Relationships among egg deposition, parr density, and smolt production in a small Newfoundland river. Canadian Atlantic Fisheries Scientific Advisory Committee working paper 92/220.


Riley, S.C., and T.J. Elms-Cockrum. 1995. Salmon spawning ground surveys, 1993. Idaho Dept. of Fish and Game, Annual Report 95-6, Boise, ID.


Bult, T.P., S.C. Riley, R.L Haedrich, and R. J. Gibson. 1995. Habitat use models for Atlantic salmon parr.  Report to the Canadian Centre for Fisheries Innovation, St. John’s, Newfoundland.


Riley, S.C., and J. Korman. 1995. Juvenile salmonid monitoring in the Cheakamus River: results of a pilot study and recommendations for monitoring design. Report to B.C. Hydro, Burnaby, B.C.


Riley, S.C., J. Korman, and S. Decker. 1997. Coquitlam River salmonid stock assessment. Report to B.C. Hydro, Burnaby, B.C.


Riley, S.C., and P.J. Lemieux. 1998. The effects of beaver on juvenile coho salmon habitat in Kispiox River tributaries. Report to Fisheries and Oceans Canada, Smithers, B.C.


Riley, S.C., J. Korman, J. Buszowski, R. Hill, and R.A. Ptolemy. 1998. Habitat-based assessment of steelhead production and escapement in the Mid-Fraser River. Report to the B.C. Ministry of Environment, Lands, and Parks, Victoria, B.C.


Riley, S.C, and E. Pucci. 1998. Fish and wildlife management on the traditional territories of the Allied Tsimshian Tribes. Report to the Allied Tsimshian Tribes, Port Simpson, B.C.


Riley, S.C., P.S. Higgins, and T. Nevin. 1998. Bridge River stream ecology and stock assessment program: 1997 Report. Report to B.C. Hydro, Burnaby, B.C.


Decker, S., J. Bratty, S.C. Riley, and J. Korman. 1999. Estimating coho salmon and cutthroat trout standing stock in a small stream: a comparison of sampling designs. Can. Tech. Rep. Fish. Aquat. Sci. 2282.


Scruton, D.A., S.C. Riley, B.A. Bennett, F.T. Bowdring, and K.D. Clarke. 2000. A review of habitat suitability criteria applicable to four salmonid species in Newfoundland, Canada. Can. Manuscr. Rep. Fish. Aquat. Sci. 2548.


Riley, S.C., P.M. Kiffney, and C. Inman. 2001. Cedar River habitat inventory and salmonid stock assessment.  Report to Seattle Public Utilities, Seattle, WA.


Riley, S.C., H.J. Fuss, and L. LeClair. 2001. Development of field methods to determine the effects of hatchery releases on wild juvenile salmonids. Report to the Hatchery Scientific Review Group, Olympia, WA.


Maynard, D.J., B.A. Berejikian, T.A. Flagg, and S.C. Riley. 2003. Development of a natural rearing system to improve supplemental fish quality.  Report to U. S. Department of Energy, Bonneville Power Administration. Project # 1991-05500, BPA Report DOE/BP00000548-01


Riley, S.C., J.A. Scheurer, C.V.W. Mahnken, and H.L. Blankenship. 2004. Assessing the potential for predation on wild salmonid fry by hatchery-reared salmonids in Washington.  Report to the Hatchery Scientific Review Group, Olympia, WA.


Riley, S. C., T. A. Flagg, J. A. Atkins, R. C. Endicott, and A. Larae.  2004. Effects of density and rearing environment on the agonistic behavior and habitat use of steelhead Oncorhynchus mykiss fry in the presence of competitors and predators in a laboratory stream.  Pages 88-110 in Maynard, D., S. Riley, and T. Flagg.  2004.  Development of a Natural Rearing System to Improve Supplemental Fish Quality.  2004 Final Report, Project No. 199105500, BPA Report DOE/BP-00004768-2.


Riley, S. C., C. P. Tatara, T. A. Flagg, R. C. Endicott and J. A. Atkins.  2004.  Growth and survival of hatchery- and naturally-reared steelhead fry in a semi-natural stream channel.  Pages 77-83 in Maynard, D., S. Riley, and T. Flagg.  2004.  Development of a Natural Rearing System to Improve Supplemental Fish Quality.  2004 Final Report, Project No. 199105500, BPA Report DOE/BP-00004768-2. 


Riley, S.C., B. A. Berejikian, and T. A. Flagg.  2004.  Effects of density and rearing environment on the behavior of steelhead Oncorhynchus mykiss fry in a laboratory stream.  Pages 44-76 in Maynard, D., S. Riley, and T. Flagg.  2004.  Development of a Natural Rearing System to Improve Supplemental Fish Quality.  2004 Final Report, Project No. 199105500, BPA Report DOE/BP-00004768-2. 


Riley, S.C., and C.P. Tatara. 2004. The ecology of residual hatchery-reared steelhead in Abernathy Creek, Washington.  Final report for USFWS Intragovernmental Agreement 13210-4-H001, Bonneville Power Administration Project 2003-063-00


Campton, D., W. Ardren, G. Zydlewski, J. Holmes, P. Crandell, K. Ostrand, W. Gale, J. Baumsteiger, B. Kennedy, S. C. Riley, and D. Seilor.  2005.  Natural reproductive success and demographic effects of hatchery origin steelhead in Abernathy Creek,Washington. 2004 Annual Report, Project No. 200306300, 65 electronic pages, (BPA Report DOE/BP-00016522-1)


Nichols, S. J., S. C. Riley, J. Craig, and G. Black.  2006.  Can zebra and quagga mussels colonize Isle Royale National Lakeshore?  Completion report to U. S. Park Service, September 2006.


Riley, S. C., K. R. Munkittrick, A. N. Evans, and C. C. Krueger.  2006.  Understanding the relationships between fish health and ecosystem dysfunction in the Great Lakes.  Research Theme Paper, Fishery Research Program, Great Lakes Fishery Commission.


Adlerstein, S., E. Rutherford, S. C. Riley, R. Haas, M. Thomas, D. Fielder, J. Johnson, J. He, and L. Mohr.  2007.  Impacts of multiple stressors on Lake Huron fish communities, 1970-2004: an integrative analysis.  Great Lakes Fishery Commission Project Completion Report, October 2007.


Ebener, M.P., L. C. Mohr, S. C. Riley, E. F. Roseman, and D. G. Fielder. 2008.  Whitefishes and ciscoes. In The state of Lake Huron in 2004. Edited by J.R. Bence and L.C. Mohr. Great Lakes Fish. Comm. Spec. Pub. 08-01. pp. 37-46.


Bence, J. R., J. E. Johnson, J. He, J. Schaeffer, S. C. Riley, R. J. Young, M. Ebener, D. Reid, L. Mohr, D. Gonder, A. Cottrill, A. Woldt, T. J. Morse, G. C. Christie, and M. Ridgway.  2008.  Offshore predators and their fish community.  In The State of Lake Huronin 2004.  Edited by J.R. Bence and L.C. Mohr.  Great Lakes Fish. Comm. Spec. Pub. 08-01. pp. 11-36.


Honeyfield, D. C., D. E. Tillit, and S. C. Riley.  Thiamine deficiency complex workshop: final report of the research coordination meeting on thiamine deficiency.   Great Lakes Fishery Commission Research Status Report.


Roseman, E. F., T. P. O’Brien, S. C. Riley, S. Farha, and J. R. P. French.  2009.  Status and trends of the Lake Huron deepwater demersal fish community, 2008.  Report submitted to the 2009 GLFC Lake Committee Meetings, Ypsilanti, MI, 27 March 2009.


Adams, J.V., S.C. Riley, and S.A. Adlerstein. 2009. Development of fishing power corrections for 12-m Yankee and 21-m wing bottom trawls used in Lake Huron. Great Lakes Fish. Comm. Tech. Rep. 68.


Daley, B.A., D.B. Bunnell, B.M. Davis, S.C. Riley, E.F. Roseman, J.F. Savino, and D.M. Warner.  2009.  The role of invasive species in Lake Huron food web disruptions.  Research Completion Report submitted to US EPA Great Lakes National Program Office, Chicago, Illinois.


Riley, S. C., E. F. Roseman, J. V. Adams, T. P. O’Brien, and S. A. Farha. 2010. Status and trends of the Lake Huron offshore demersal fish community, 1976-2009.  Report submitted to the 2010 GLFC Lake Committee Meetings, Windsor, ON, March 2010.


Roseman, E. F., S. C. Riley, J. V. Adams, S. A. Farha, and H. K. Avis.  2011.  Status and Trends of the Lake Huron Offshore Demersal Fish Community, 1976-2010.  Report submitted to the 2011 GLFC Lake Committee Meetings, Ypsilanti, MI, 22 March 2011.  


Ebener, M. P., S. C. Riley, J. Rinchard, and D. E. Tillitt.  2011.  Are thiamine levels in lake whitefish eggs in the upper Great Lakes lower in fish that consume dreissenid mussels?  Great Lakes Fishery Commission Project Completion Report, Ann Arbor, MI.


Popular articles


Riley, S.C. 1986. To sea or not to sea: how different are landlocked and anadromous salmon? Atlantic Salmon Journal, Sept. 1986.


Fausch, K.D., and S.C. Riley. 1992. Do log-drop structures increase trout? Colorado Trout Unlimited, Rocky Mountain Streamside, Summer 1992: 10-12.


Riley, S.C. 1993. Cape Race - a diamond in the rough.  Newfoundland Lifestyle 11(1):54.


Riley, S.C., and R.J. Gibson. 1993. Hydroelectric development in Newfoundland: Boon or boondoggle? Osprey (Newfoundland Natural History Society Quarterly) 24:50-58.


Riley, S.C., G. Power, and R.L. Haedrich. 1993. The absurd flaw in the management of wild salmon. Atlantic Salmon Journal, Winter 1993.


Fausch, K.D., C. Gowan, and S.C. Riley. 1996. Log drop structures: what’s the bottom line? Colorado Trout Unlimited, Rocky Mountain Streamside, Spring 1996:25-28.