Interactive effects of contaminants and climate‐related stressors: High temperature increases sensitivity to cadmium

Abstract

An emerging issue in environmental toxicology is in understanding how climate change will alter responses of organisms to chemical contaminants. The objective of the present study was to characterize the interactive effects of cadmium and elevated temperature on life-stage-specific responses in the freshwater snail Physa pomilia. We exposed developing eggs, juveniles, and adults to Cd (5 µg/L, 15 µg/L, and 25 µg/L for eggs, and 250 µg/L for juveniles and adults) and 2 temperatures of 25 °C (control) and 35 °C (upper range of tolerance). In the absence of Cd, time to hatch was shorter at 35 °C compared with 25 °C, demonstrating a stimulatory effect of the higher temperature. However, when egg masses were reared at 35 °C and exposed to Cd, hatching success was significantly lower, and time-to-hatching was significantly longer. The effects of the higher temperature and Cd on newly hatched neonate survival were additive, except at the highest Cd concentration, at which effects of the 2 stressors were greater than additive. Overall, within the combined stressor treatments, adult snails generally survived significantly longer than did juvenile snails, and both were more tolerant than developing snails. Many climate projection models predict future increases in global temperatures. The present study shows that combined stressors may produce greater-than-additive effects, challenging predictive power. More studies are needed to better characterize the interactive effects of chemical contaminants and stressors related to climate change.

Assessing the impacts of dimethoate on rotifers′ reproduction through the pre-exposure history

“…Many evidences suggested that the timing when organisms experience stressful conditions could influence the onset and severity of the adverse effect (Wu et al, 2012;Kimberly and Salice, 2013). We found that the pre-exposure to sub-lethal concentrations of dimethoate produced the latent effects at later stages in the form of reduced reproduction and decreased lifespan.…”

Toxicity delayed in cold freshwaters?

“…Warmer temperatures generally result in increased toxicity of environmental contaminants (e.g., Heugens et al, 2001;Noyes et al, 2009;Kimberly and Salice, 2013;Zhou et al, 2014;Laetz et al, 2014). Temperature variability can also increase the sensitivity of aquatic organisms to toxicants (Kimberly and Salice, 2014) and, conversely, toxicants can increase the sensitivity of organisms to temperature (Little and Seebacher, 2015).…”

The pros and cons of ecological risk assessment based on data from different levels of biological organization

“…This is a significant limitation because the toxicity of many contaminants is often highly context dependent, changing with environmental conditions, such as light, pH, hydroperiod, and temperature gradients (Barron et al 2003, Kimberly and Salice 2013, Noyes et al 2009, Rohr et al 2004, Rohr, Johnson, et al 2013, Rohr and Palmer 2005, Rohr et al 2011, Stampfli et al 2011), and common intra- and interspecific interactions (Relyea 2003, Relyea et al 2005, Rohr and Crumrine 2005, Rohr, Raffel, et al 2008). For example, warming up cells, tissues, or organs in isolation will not necessarily produce the same results as warming up an entire organism.…”