Physiological and ecological effects of increasing temperature on fish production in lakes of Arctic Alaska

Abstract

Lake ecosystems in the Arctic are changing rapidly due to climate warming. Lakes are sensitive integrators of climate-induced changes and prominent features across the Arctic landscape, especially in lowland permafrost regions such as the Arctic Coastal Plain of Alaska. Despite many studies on the implications of climate warming, how fish populations will respond to lake changes is uncertain for Arctic ecosystems. Least Cisco (Coregonus sardinella) is a bellwether for Arctic lakes as an important consumer and prey resource. To explore the consequences of climate warming, we used a bioenergetics model to simulate changes in Least Cisco production under future climate scenarios for lakes on the Arctic Coastal Plain. First, we used current temperatures to fit Least Cisco consumption to observed annual growth. We then estimated growth, holding food availability, and then feeding rate constant, for future projections of temperature. Projected warmer water temperatures resulted in reduced Least Cisco production, especially for larger size classes, when food availability was held constant. While holding feeding rate constant, production of Least Cisco increased under all future scenarios with progressively more growth in warmer temperatures. Higher variability occurred with longer projections of time mirroring the expanding uncertainty in climate predictions further into the future. In addition to direct temperature effects on Least Cisco growth, we also considered changes in lake ice phenology and prey resources for Least Cisco. A shorter period of ice cover resulted in increased production, similar to warming temperatures. Altering prey quality had a larger effect on fish production in summer than winter and increased relative growth of younger rather than older age classes of Least Cisco. Overall, we predicted increased production of Least Cisco due to climate warming in lakes of Arctic Alaska. Understanding the implications of increased production of Least Cisco to the entire food web will be necessary to predict ecosystem responses in lakes of the Arctic.

Generalist feeding strategies in Arctic freshwater fish: A mechanism for dealing with extreme environments

“…In a climate scenario study, young-of-year lake trout have difficulty acquiring adequate zooplankton resources to compensate for increased metabolic rates (McDonald et al, 1996). In contrast, the effects of warming were less dire for least cisco, a species with generalist feeding behaviours; a bioenergetics model predicted increased growth among all age classes of fish provided they can maintain their current feeding rates (Carey & Zimmerman, 2014). In contrast, the effects of warming were less dire for least cisco, a species with generalist feeding behaviours; a bioenergetics model predicted increased growth among all age classes of fish provided they can maintain their current feeding rates (Carey & Zimmerman, 2014).…”

“…Future climate projections for the region indicate an annual temperature increase of 7.3°C by the end of the century (Martin et al, 2009). The balance between available food and metabolic need will ultimately determine future fish production (Carey & Zimmerman, 2014;McDonald et al, 1996). Climatic changes may also enhance planktonic primary production (Rautio et al, 2011) and increase fish metabolic needs and their associated food requirements .…”

An ecohydraulics virtual watershed: Integrating physical and biological variables to quantify aquatic habitat quality

“…These impacts may force changes to water resources development, operation, and management in the future. Interaction between flow releases, timing, and dam operation on stream thermal regimes are key elements for aquatic habitat quality (Carey & Zimmerman, 2014;Danehy, Colson, Parrett, & Duke, 2005;Hébert, Caissie, Satish, & El-Jabi, 2015;Johnson, Saito, Anderson, Andre, & Fontane, 2004;Lessard & Hayes, 2003;Loinaz, Davidsen, Butts, & Bauer-Gottwein, 2013;Torgersen, Price, Li, & McIntosh, 1999). The interaction between key habitat elements is often overlooked and a major gap in current environmental flow assessments (Olden & Naiman, 2010).…”

Impacts of deforestation‐induced warming on the metabolism, growth and trophic interactions of an afrotropical stream fish

“…When energy is limited, the "metabolic costs" of warming can translate into lower investment in growth and reproduction and ultimately a decline in fitness. Fishes, for example, can suffer growth impairment due to the metabolic costs of warming in laboratory experiments when ration is restricted (Cui & Wootton, 1988) or in nature when prey availability is low (Carey & Zimmerman, 2014). However, when energy supply is sufficient and when warming is not severe enough to exceed thermal tolerance limits, ectotherms can compensate for metabolic costs of warming by increasing their energy intake and achieve similar or even higher growth rates (Carey & Zimmerman, 2014;Cui & Wootton, 1988;Neuheimer, Thresher, Lyle, & Semmens, 2011;O'Gorman et al, 2016).…”