Climate change effects on arctic freshwater fish populations

May 7, 2012, 12:41 pm

This is Section 8.5.3 of the Arctic Climate Impact Assessment
Lead Authors:  Frederick J.Wrona,Terry D. Prowse, James D. Reist;  Contributing Authors: Richard Beamish, John J. Gibson, John Hobbie, Erik Jeppesen, Jackie King, Guenter Koeck, Atte Korhola, Lucie Lévesque, Robie Macdonald, Michael Power,Vladimir Skvortsov,Warwick Vincent;  Consulting Authors: Robert Clark, Brian Dempson, David Lean, Hannu Lehtonen, Sofia Perin, Richard Pienitz, Milla Rautio, John Smol, Ross Tallman, Alexander Zhulidov


The ability of fish to adapt to changing environments is species-specific. In the case of rapid temperature increases associated with climate change, there are three possible outcomes for any species: local extinction due to thermal stress, a northward shift in geographic range where dispersive pathways and other biotic and abiotic conditions allow, and genetic change within the limits of heredity through rapid natural selection. All three are likely to occur, depending on the species[1]. Local extinctions are typically difficult to project without detailed knowledge of critical population parameters (e.g., fecundity, growth, mortality, population age structure, etc.). Dispersal and subsequent colonization are very likely to occur, but will very probably be constrained by watershed drainage characteristics and ecological and historical filters[2]. In watershed systems draining to the north, increases in temperature are very likely to allow some species to shift their geographic distribution northward (see section In watershed systems draining to the east or west, increases in temperature will possibly be compensated for by altitudinal shifts in riverine populations where barriers to movements into headwaters do not exist. Lake populations needing to avoid temperature extremes are very likely to be confined to the hypolimnion during the warmest months provided anoxic conditions do not develop. Patterns of seasonal occurrence in shallower littoral zones are very likely to change, with consequent effects on trophic dynamics. Changes in species dominance will very probably also occur because species are adapted to specific spatial, thermal, and temporal characteristics that are very likely to alter as a result of climate-induced shifts in precipitation and temperature.

Before successful range extensions can occur, habitat suitability, food supply, predators, and pathogens must be within the limits of the niche boundaries of the species. In addition, routes to dispersal must exist. Physiological barriers to movement such as salinity tolerances or velocity barriers (i.e., currents) will possibly restrict range extensions where physical barriers to migration (e.g., waterfalls, non-connected drainage basins) do not exist. Against this background of dynamic physical and biotic changes in the environment, some regional and species-specific climate change projections have been made.

Region 1: European percids (

Under scenarios of climate change, spawning and hatching of spring and summer spawning populations are likely to occur earlier in the year. For example, European perch are very likely to advance spring spawning by as much as a month[3] and juveniles will very probably experience longer growth periods and reach larger sizes at the end of the first summer. However, this species may not realize the potential benefits of increased size if higher egg incubation temperatures are associated with smaller larvae having smaller yolk sacs and increased metabolic rates[4]. Small larvae are more susceptible to predation, have higher mortality rates, and have a shorter period during which they must adapt to external feeding to survive[5]. In addition, increased overwinter survival is very likely to be associated with increased demand for prey resources and will possibly lead directly to population stunting (i.e., smaller fish sizes).

The zander (Sander lucioperca) is a eurythermal species distributed widely in Europe whose growth and recruitment success correlates with temperature[6]. The present northern distribution coincides with the July 15°C isotherm and is likely to shift northward with climate change. Successive year-class strengths and growth rates in northern environments are also likely to increase as temperatures increase. Increases in both abundance and size are very likely to have consequences for the competitiveness of resident coldwater-guild fishes if concomitant increases in lake productivity fail to yield sufficient ration to meet the needs of expanding populations of zander and other percids. Evidence that northward colonization is already occurring comes from the Russian portion of Region 1. Over the last 10 to 15 years, northern pike, ide (Leuciscus idus), and roach (Rutilus rutilus lacustris) have become much more numerous in the Pechora River Delta and the estuary Sredinnaya Guba (~68° N) of the Barents Sea[7].

Region 2: Fishes in Siberian rivers (

Many species of fish in the large northward flowing rivers of Siberia have the potential for significant northward range extensions and/or responses to climate change. Several species in the Yenisey and Lena Rivers that prefer warmer boreal-plain habitats (e.g., roach, ide, common dace – Leuciscus leuciscus baicalensis, European perch, and ruffe – Gymnocephalus cernuus) are likely to move into the northern mouth areas of these rivers that are currently dominated by whitefishes and chars. Overall, fish species diversity is likely to increase, but this probably will be at the expense of the coldwater salmonids. The speed at which this process might occur is uncertain, however, it may already be occurring and is likely to be within approximately the next ten years. In addition, as environments change, intentional stocking of other species (e.g., carp bream – Abramis brama and zander) is likely to occur in the area, which is likely to result in additional pressures upon native arctic fish populations.

Region 3: Alaskan game fish (

Nutrient availability often determines food availability and lotic productivity, which are believed to be major controlling factors in riverine fish production. Several studies have found that fish density and growth correlate with nutrient status and food availability in streams, with larger standing crops in nutrient-rich streams[8]. In particular, salmonid biomass in nutrient-poor environments varies with nutrient levels, habitat type, and discharge[9]. The bottom-up propagation of nutrients through algal and invertebrate production to fish has been projected to be a possible result of climate-induced increases in nutrient additions associated with permafrost degradation. However, this premise has rarely been tested, and the relationship between nutrient loading and fish production is poorly understood[10]. Shifts in stable carbon and nitrogen isotope distributions have demonstrated a coupling between the stimulation of benthic algal photosynthesis and accelerated growth in stream-resident insect and fish populations[11]. In addition, experimental fertilization of Alaskan tundra rivers has demonstrated increased growth rates for adult and young-of-the-year Arctic grayling, with the strongest response observed in the latter[12].

Temperature increases associated with climate change are also likely to be associated with lower flows, with which growth of adult Arctic grayling is also highly correlated. At low flows, adult growth is low, whereas young-of-the-year continue to grow well[13]. As Arctic grayling in many Alaskan systems are already food-limited, the associated increases in metabolic costs are likely to be associated with decreased survival unless nutrient loading associated with permafrost degradation offsets the increased metabolic costs of low-flow conditions[14].

Lake trout are a keystone predator in many Alaskan lakes. Low food supply and temperatures, however, keep the species near physiological limits for survival with the result that lake trout will possibly be particularly sensitive to changes in either temperature or food supply initiated by climate change[15]. Increases in temperature are very likely to increase metabolic demands, which will very probably lead to lower realized growth rates unless met by sufficient increases in ration.

Many populations are already food-limited, which suggests that further increases in temperature are very likely to have significant effects on population abundance. Bio-energetic modeling of juvenile populations of lake trout in the epilimnion of Toolik Lake suggests that they will not survive a 3°C increase in mean July epilimnetic temperatures given existing ration, and would require a greater than eight-fold increase in food to achieve historical end-of-year sizes[16]. Documented increases in epilimnetic temperatures, however, have not been associated with increased food availability. If recent changes in the lake foreshadow long-term trends, these modeling results suggest that young lake trout will not overwinter successfully, and the associated changes in mortality patterns may lead to local extinction and the disruption of lake-trout control of the trophic structure in many arctic lakes[17].

Region 4: Northern Québec and Labrador salmonid and pike populations (

Among the salmonids of northern Québec and Labrador, the response to temperature changes is very likely to track physiological preferences for warmer waters. Several species, such as native Atlantic salmon and brook trout (Salvelinus fontinalis) and introduced brown trout and rainbow trout (Oncorhynchus mykiss), are very likely to extend their ranges northward. While the warmer-water percid and cyprinid species are restricted to the southwest and unlikely to extend their range to the north (unless moved by humans) because of dispersal barriers[18], the euryhaline salmonids are able to move from estuary to estuary as conditions allow. For example, Dumont et al.[19] documented the successful movement of rainbow and brown trout and exotic salmon species in the estuary of the Gulf of St. Lawrence, and there is some indication that brown trout dispersal in Newfoundland has been temperature-limited[20]. As a result of probable range extensions, Arctic char are very likely to be reduced or replaced by anadromous Atlantic salmon and/or anadromous brook trout throughout much of the southern portion of the region and brook trout are very likely to become a more important component of native subsistence fisheries in rivers now lying within the tundra zone[21]. Lake trout are likely to disappear from rivers and the shallow margins of many northern lakes and behave as currently observed in temperate regions[22].

Northern pike habitats in much of subarctic North America and Europe are projected to sustain some of the most severe consequences of global climate change. Adult northern pike actively avoid surface temperatures in excess of 25°C, which are very likely to become more frequent as air temperatures increase throughout much of the distributional range. In shallower lakes, changes in lake chemistry associated with temperature increases will possibly result in cooler bottom waters becoming anoxic and a restriction of suitable habitat[23]. Studies in Ohio impoundments have shown that although northern pike show summer growth, there is an associated weight loss during the periods of habitat restriction[24]. Accordingly, northern pike throughout much of their current range are expected to be restricted in both numbers and size as a result of climate change.

Attempts to relate fish yields and mean annual air temperatures have been coupled with geographic information techniques to project shifts in both distribution and yields of important freshwater fishes in this region[25]. In general throughout subarctic Québec, yields for lake whitefish are projected to increase by 0.30 to >1.0 kg/ha/yr. Northern pike yields in southern portions of the Hudson Bay drainage are projected to increase by 0.03 to 0.10 kg/ha/yr, and those in northern portions to increase marginally (0.01–0.03 kg/ha/yr). Walleye yields in the southern drainage basin of Hudson Bay are projected to increase by 0.01 to 0.10 kg/ha/yr. These changes are projected to result from occupancy of new, presently unsuitable areas in the north, and increased overall productivity throughout the entire area. Declining production in southern areas that become unsuitable due to suboptimal thermal regimes for these species or local population extirpation may possibly offset the overall productivity gains.


Chapter 8: Freshwater Ecosystems and Fisheries
8.1. Introduction
8.2. Freshwater ecosystems in the Arctic
8.3. Historical changes in freshwater ecosystems
8.4. Climate change effects
        8.4.1. Broad-scale effects on freshwater systems
        8.4.2. Effects on hydro-ecology of contributing basins
        8.4.3. Effects on general hydro-ecology
        8.4.4. Changes in aquatic biota and ecosystem structure and function
8.5. Climate change effects on arctic fish, fisheries, and aquatic wildlife
        8.5.1. Information required to project responses of arctic fish
        8.5.2. Approaches to projecting climate change effects on arctic fish populations
        8.5.3. Climate change effects on arctic freshwater fish populations
        8.5.4. Effects of climate change on arctic anadromous fish
        8.5.5. Impacts on arctic freshwater and anadromous fisheries
        8.5.6. Impacts on aquatic birds and mammals
8.6. Ultraviolet radiation effects on freshwater ecosystems
8.7. Global change and contaminants
8.8. Key findings, science gaps, and recommendations


  1. ^ Lehtonen, H., 1996. Potential effects of global warming on northern European freshwater fish and fisheries. Fisheries Management and Ecology, 3:59–71.
  2. ^ Tonn, W.M., 1990. Climate change and fish communities: a conceptual framework. Transactions of the American Fisheries Society, 119:337–352.
  3. ^ Lehtonen, H., 1996. Potential effects of global warming on northern European freshwater fish and fisheries. Fisheries Management and Ecology, 3:59–71.
  4. ^ Blaxter, J.H.S., 1992. The effect of temperature on larval fishes. Netherlands Journal of Zoology, 42:336–357.
    –Peterson, R.H., H.C.E. Spinney and A. Sreedharan, 1977. Development of Atlantic salmon (Salmo salar) eggs and alevins under varied temperature regimes. Journal of the Fisheries Research Board of Canada, 34:31–43.
  5. ^ Blaxter, J.H.S., 1992. Op.cit.
  6. ^ Colby, P.J. and H. Lehtonen, 1994. Suggested causes for the collapse of zander Stizostedion lucioperca (L.) populations in northern and central Finland through comparisons with North American walleye, Stizostedion vitreum (Mitchill). Aqua Fennica, 24:9–20.
  7. ^ A. Kasyanov, 2004. Pers. comm. Institute of Inland Waters, Russian Academy of Sciences.
  8. ^ Bowlby, J.N. and J.C. Roff, 1986. Trout biomass and habitat relationships in southern Ontario streams. Transactions of the American Fisheries Society, 115:503–514.
    –McFadden, J.T. and E.L. Cooper, 1962. An ecological comparison of six populations of brown trout (Salmo trutta). Transactions of the American Fisheries Society, 91:53–62.
    –Murphy, M.L., C.P. Hawkins and N.H. Anderson, 1981. Effects of canopy modification and accumulated sediment on stream communities. Transactions of the American Fisheries Society, 110:469–478.
  9. ^ Gibson, R.J. and R.L. Haedrich, 1988. The exceptional growth of juvenile Atlantic salmon (Salmo salar) in the city waters of St. John's, Newfoundland, Canada. Polskie Archiwum Hydrobiologii, 35:385–407.
  10. ^ Peterson, B.J., J.E. Hobbie, T.L. Corliss and K. Kriet, 1983. A continuous-flow periphyton bioassay: tests of nutrient limitation in a tundra stream. Limnology and Oceanography, 28:583–591.
  11. ^ Peterson, B.J., L. Deegan, J. Helfrich, J.E. Hobbie, M. Hullar, B. Moller, T.E. Ford, A. Hershey, A. Hiltner, G. Kipphut, M.A. Lock, D.M. Fiebig, V. McKinley, M.C. Miller, J.R. Vestal, J. Robie, R. Ventullo and G. Volk, 1993. Biological responses of a tundra river to fertilization. Ecology, 74:653–672.
  12. ^ Deegan, L.A. and B.J. Peterson, 1992. Whole-river fertilization stimulates fish production in an Arctic tundra river. Canadian Journal of Fisheries and Aquatic Sciences, 49:1890–1901.
  13. ^ Ibid.
  14. ^ Rouse, W.R., M.S.V. Douglas, R.E. Hecky, A.E. Hershey, G.W. Kling, L. Lesack, P. Marsh, M. McDonald, B.J. Nicholson, N.T. Roulet and J.P. Smol, 1997. Effects of climate change on the freshwaters of Arctic and subarctic North America. Hydrological Processes, 11:873–902.
  15. ^ McDonald, M.E., A.E. Hershey and M.C. Miller, 1996. Global warming impacts on lake trout in Arctic lakes. Limnology and Oceanography, 41:1102–1108.
  16. ^ Ibid.
  17. ^ Ibid.
  18. ^ Power, G., 1990b. Salmonid communities in Quebec and Labrador: temperature relations and climate change. Polskie Archiwum Hydrobiologii, 37:13–28.
  19. ^ Dumont, P., J.F. Bergeron, P. Dulude, Y. Mailhot, A. Rouleau, G. Ouellet and J.-P. Lebel, 1988. Introduced salmonids: where are they going in Québec watersheds of the Saint-Laurent River? Fisheries, 13:9–17.
  20. ^ Crossman, E.J., 1984. Introduction of exotic fishes into Canada. In: W.R. Courtenay Jr. and J.R. Stauffer Jr. (eds.). Distribution, Biology and Management of Exotic Fishes, pp. 78–101. John Hopkins University Press, Baltimore.
  21. ^ Power, G., 1990b. Salmonid communities in Quebec and Labrador: temperature relations and climate change. Polskie Archiwum Hydrobiologii, 37:13–28.
  22. ^ Martin, N.V. and C.H. Olver, 1980. The lake charr, Salvelinus namaycush. In: E.K. Balon (ed.). Charrs: Salmonid Fishes of the Genus Salvelinus, pp. 205–277. Dr.W. Junk Publishers.
  23. ^ Schindler, D.W., K.G. Beaty, E.J. Fee, D.R. Cruikshank, E.R. DeBruyn, D.L. Findlay, G.A. Linsey, J.A. Shearer, M.P. Stainton and M.A. Turner, 1990. Effects of climate warming on lakes of the central boreal forest. Science, 250:967–970.
  24. ^ Headrick, M.R. and R.F. Carline, 1993. Restricted summer habitat and growth of northern pike in two southern Ohio impoundments. Transactions of the American Fisheries Society, 122:228–236.
  25. ^ Minns, C.K. and J.E. Moore, 1992. Predicting the impact of climate change on the spatial pattern of freshwater fish yield capability in eastern Canadian lakes. Climatic Change, 22:327–346.
  26. ^ Power M. and Power, 1994, Op. cit.
  27. ^Shuter, B.J. and J.R. Post, 1990. Climate, population viability, and the zoogeography of temperate fishes.Transactions of the American Fisheries Society, 119:314–336.
  28. ^Power, G., 1990a., Op. cit.
  29. ^Doucett, R.R., 1999. Food-web relationships in Catamaran Brook, New Brunswick, as revealed by stable-isotope analysis of carbon and nitrogen. Ph.D Thesis, University of Waterloo, Ontario.






Committee, I. (2012). Climate change effects on arctic freshwater fish populations. Retrieved from


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