Temperature‐dependent ultraviolet responses in zooplankton: Implications of climate change

Abstract

Climate warming and stratospheric ozone depletion increase temperature and ultraviolet (UV) in mid‐ to highlatitude ecosystems; however, little is known about the interactive effects of temperature and UV on organisms. We exposed Daphnia catawba, Leptodiaptomus minutus, and Asplanchna girodi to UV‐B at four different temperatures: 10, 15, 20, and 25°C. Elevated temperatures increased UV tolerance in D. catawba and L. minutus, species that depend heavily on photoenzymatic repair (PER), but decreased UV tolerance in A. girodi, a species that has less PER. Also, body size in Daphnia decreased with increasing UV dose. These results demonstrate that climate change can alter responses to UV through temperature‐mediated effects in aquatic ecosystems, and these effects can be species‐specific and dependent on PER ability.

Differential tolerance to ultraviolet-B light and photoenzymatic repair in cladocerans from a Chilean lake

“…Pigmentation involves a trade-off between UV protection and predation risk, because animals with greater pigmentation are more vulnerable to predation by visual predators (Hansson 2000;Johnsen and Widder 2001). Photoenzymatic repair is temperature dependent and, consequently, its effectiveness will vary seasonally (Williamson et al 2002). Ultimately, each individual organism will exhibit particular capabilities to avoid or tolerate (either through preventive protection or repair mechanisms) the harmful effects of UV-B, depending on genetic constraints, physiological state and environmental conditions.…”

Roles of phosphorus and ultraviolet radiation in the strength of phytoplankton‐zooplankton coupling in a Mediterranean high mountain lake

“…High mountain lakes are climatically sensitive indicators useful in predicting global change (Williamson et al 2009). Although extrapolation of our experimental results to the full-scale system is limited, since natural conditions are not completely reproduced by mesocosms closed at the bottom (e.g., by preventing nutrient sedimentation and constraining zooplankton migration), both experimental and longterm approaches can help to qualitatively explain the phytoplankton-zooplankton relationship in Lake La Caldera.…”

“…While the role of global warming on PZC is well studied (Winder and Schindler 2004;Domis et al 2007;Sommer et al 2007), additional work is required to elucidate the contribution of other joint global factors. There has been enormous research interest in developing our understanding of the response of organisms and ecosystems to the interaction between UVR and other global stressors (Williamson et al 2002;Vinebrooke and Leavitt 2005). However, the nature of this interaction is difficult to predict, and effects are not necessarily straightforward.…”

“…We tested this hypothesis in an experiment in which large mesocosms were incubated in situ in the presence and absence of UVR across an experimental P gradient in a high mountain lake. High mountain lakes are ''sentinels of change'' (Williamson et al 2009), offering ideal natural scenarios for testing the effects and mechanisms of climate change. These types of lakes are ultrasensitive to atmospheric inputs, largely due to the oligotrophy associated with their remote location.…”

Effects of experimental warming and increased ultraviolet B radiation on the Mediterranean plankton food web

“…However, few multifactorial experiments have been dedicated to studying the effect of multiple global change stressors on aquatic ecosystems, and very few have studied the effects at several trophic levels. For example, it has been found that the effect of UVBR may be temperature dependent because temperature enhances photo-enzymatic repair (Williamson et al 2002;MacFadyen et al 2004). Another study (Doyle et al 2005) has shown that the effect of UVBR on phytoplankton growth is not only temperature dependent but also nutrient dependent.…”