Opposite responses by an intertidal predator to increasing aquatic and aerial temperatures

Abstract

Predicting the effects of climate change on ecosystems requires an understanding of how temperature alters organismal physiology and behavior. Because predation can shape patterns of abundance and diversity across a community, it is critical to understand the effect of temperature on predator behavior. Climate change in intertidal systems will comprise changes in both air and water temperatures, yet most previous marine intertidal studies have focused on either air or water temperature alone. In a 20 d laboratory study, we examined the effect of changing emersed and submersed body temperatures on the feeding and growth rates of Nucella ostrina, a common northeastern Pacific intertidal gastropod that feeds primarily on the barnacle Balanus glandula. Our results revealed a large increase in both predation and growth rates with higher submersion temperatures (13.5°C compared with 11°C). In contrast, we observed a large decrease in the feeding and growth of N. ostrina exposed to the highest emersed body temperature (28°C) when compared with intermediate (20°C) and cooler (12°C) aerial temperatures. Thus, while B. glandula may suffer greater predation-related mortality in warmer water temperatures, it may actually experience a release from predation if air temperatures warm. Our study points to the importance of considering temperatures reached during both submersion and emersion separately, and examining behavioral responses in light of physiologically relevant temperatures and thermal regimes.

The importance of thermal history: costs and benefits of heat exposure in a tropical, rocky shore oyster

“…The combination of these two functional parameters, however, shows that the oysters emersed at lower temperatures are able to maximise their energy absorption as compared with those emersed at 40°C, indicating a clear trade-off between enhanced thermal tolerance, driven by the energetically costly hsp response, and the capacity to optimise energy intake and assimilation following heat stress. Increasing water temperatures have been demonstrated to enhance predation activity and feeding rates of mobile intertidal gastropods (Yamane and Gilman, 2009). In contrast, within each air exposure treatment of the present study, feeding performance of the oyster did not differ between the two temperatures, indicating that these traits may be less susceptible to temperature change in sessile molluscs.…”

Survival and arm abscission are linked to regional heterothermy in an intertidal sea star

“…Biophysical studies have emphasized that body temperature varies not only as a function of microhabitat (Denny et al, 2011), but also with factors such as body size, which can affect an organism's thermal inertia (Turner, 1988;Helmuth, 1998;Pincebourde et al, 2009). These studies have also been used successfully to explore the impacts of environmental change in terms of growth and reproduction (Kearney et al, 2010;Schneider et al, 2010;Sarà et al, 2011), and rates of predation and thus interaction strengths between species (Sanford, 2002;Yamane and Gilman, 2009;Monaco and Helmuth, 2011).…”

Thermal tolerance of the crab Pachygrapsus marmoratus: intraspecific differences at a physiological (CTMax) and molecular level (Hsp70)

“…Temperature exerts its effects at different levels of organization for instance molecular, biochemical, physiological, and behavioral (Mora and Ospina 2001;Hochachka and Somero 2002;Dent and Lutterschmidt 2003). It also affects community interactions (Yamane and Gilman 2009) and ecosystem structure (Glynn 1988). Thermal stress leads to changes in energy allocation for the organism's activities such as growth, reproduction and foraging, with consequences in performance and fitness.…”

“…The intertidal zone and its inhabiting communities have served as models in climate studies (see Helmuth et al 2006;Yamane and Gilman 2009). Organisms living in greater vertical shore heights have evolved specific adaptations that allow them to cope with environmental stress due to exposure to terrestrial conditions (Stillman 2002).…”