A perspective on the ecological and evolutionary consequences of phenological variability in lake ice on north-temperate lakes

Abstract

Climate change is leading to shifts in not only the average timing of phenological events, but also their variance and predictability. Increasing phenological variability creates a stochastic environment that is critically understudied, particularly in aquatic ecosystems. We provide a perspective on the possible implications for increasingly unpredictable aquatic habitats, including more frequent trophic asynchronies and altered hydrologic regimes, focusing on ice-off phenology in lakes. Increasingly frequent phenological extremes may limit the ability of organisms to optimize traits required to adapt to a warming environment. Using a unique, long-term ecological dataset on Escanaba Lake, WI, USA as a case study, we show that the average date of ice-off is shifting earlier and becoming more variable, thus altering limnological conditions and yielding uncoupled food web responses with ramifications for fish spawn timing and recruitment success. A genes-to-ecosystems understanding of the responses of aquatic communities to increasingly variable phenology is needed. Our perspective suggests that management for diversity, at the intra- and inter-specific levels, will become paramount for conserving resilient aquatic ecosystems.

Density‐dependent and environmental influences on juvenile walleye Sander vitreus (Mitchill) survivorship in northern Wisconsin lakes

“…Factors contributing to increased juvenile walleye mortality with increased May surface water temperature could be related to climate change, elevated larval walleye abundance, and predation from other species due to increased metabolic rates. Climate change has caused shorter winter ice durations and earlier and more variable ice‐off dates on north temperate lakes (Feiner et al, 2022; Jensen et al, 2007; Magnuson et al, 2000; Sharma et al, 2021). As a result, May surface water temperatures that have increased and become more variable over time could disturb average phenological processes and increase the potential for trophic mismatches in juvenile walleye (Cushing, 1990; Feiner et al, 2022).…”

“…Climate change has caused shorter winter ice durations and earlier and more variable ice‐off dates on north temperate lakes (Feiner et al, 2022; Jensen et al, 2007; Magnuson et al, 2000; Sharma et al, 2021). As a result, May surface water temperatures that have increased and become more variable over time could disturb average phenological processes and increase the potential for trophic mismatches in juvenile walleye (Cushing, 1990; Feiner et al, 2022). For example, earlier ice offs and elevated spring water temperatures could decouple peak abundance of phytoplankton and zooplankton (Winder & Schindler, 2004) and zooplankton and fish hatching (Ohlberger et al, 2014).…”

“…For example, earlier ice offs and elevated spring water temperatures could decouple peak abundance of phytoplankton and zooplankton (Winder & Schindler, 2004) and zooplankton and fish hatching (Ohlberger et al, 2014). Therefore, the positive correlation between age‐0 and age‐1 walleye mortality and May surface water temperature may be explained by an increasing prevalence of trophic mismatches during juvenile walleye ontogeny (Cushing, 1990; Feiner et al, 2022; Gostiaux et al, 2022). Higher May surface water temperatures may also increase piscivore metabolic rates and associated consumptive demand (Kitchell et al, 1977).…”

“…Lake stratification is likely to limit walleye habitat by limiting the area of a lake with optimal temperature and dissolved oxygen (Arend et al, 2011; Hansen et al, 2017). Additionally, duration of lake stratification is likely indicative of warmer or cooler annual trends in temperature, whereby longer periods of stratification are more likely to be associated with warm years and vice versa (Feiner et al, 2022; Hansen et al, 2017). Lake‐specific morphological data (lake surface area and SDF) were obtained from Hansen et al (2015).…”

“…Extreme temperatures (i.e. peak annual water temperature), variability in spring water temperature (coefficient of variation in temperature from zero to 30 days post-ice-out; CV 0-30 days) and winter severity (ice cover duration; days) have been shown to influence walleye recruitment (Feiner et al, 2022;Hansen et al, 1998Hansen et al, , 2015Hansen et al, , 2017Honsey et al, 2020). Additionally, temperature effects on metabolism and growth during early life stages (i.e.…”