More ecological ERA: Incorporating natural environmental factors and animal behavior

Abstract

We discuss the importance of selected natural abiotic and biotic factors in ecological risk assessment based on simplistic laboratory bioassays. Although it is impossible to include all possible natural factors in standard lower-tier ecotoxicological testing, neglecting them is not an option. Therefore, we try to identify the most important factors and advocate redesigning standard testing procedures to include theoretically most potent interactions. We also point out a few potentially important factors that have not been studied enough so far. The available data allowed us to identify temperature and O2 depletion as the most critical factors that should be included in ecotoxicity testing as soon as possible. Temporal limitations and fluctuations in food availability also appear important, but at this point more fundamental research in this area is necessary before making decisions on their inclusion in risk assessment procedures. We propose using specific experimental designs, such as Box-Behnken or Central Composite, which allow for simultaneous testing of 3 or more factors for their individual and interactive effects with greater precision and without increasing the effort and costs of tests dramatically. Factorial design can lead to more powerful tests and help to extend the validity of conclusions. Finally, ecological risk assessment procedures should include information on animal behavior, especially feeding patterns. This requires more basic studies, but already at this point adequate mechanistic effect models can be developed for some species.

Exposure to a heat wave under food limitation makes an agricultural insecticide lethal: a mechanistic laboratory experiment

“…While there is a long history of identifying the relevance of delayed effects of stressors (e.g., Abel, ; Liess, ), our results feed the increasing concern for delayed interactions among stressors as these are typically ignored in risk assessment (Segner, ; Bednarska et al ., ). The here‐identified strong delayed synergism with heat waves and food shortage will indeed not be detected in standard ecotoxicological testing of pesticides, even when executed at different temperatures (Bednarska et al ., ).…”

Temperature-dependent effects of PFOS on risk recognition and fast-start performance in juvenile Spinibarbus sinensis

“…The increased toxicity of PFOS at the higher temperature was probably due to a faster uptake, absorption and bioaccumulation (Del Piero et al 2012). The observed temperature-dependent PFOS effects on risk recognition and fast-start performance of the fish provide further support to the appeal by Bednarska et al (2013) to include a range of realistic temperatures in standard eco toxicity tests. Our study indicates that PFOS as an environmental pollutant could have ecological consequences for wild fish by decreasing risk recognition and escape behaviors.…”

Biotic and abiotic factors investigated in two Drosophila species – evidence of both negative and positive effects of interactions on performance

“…This is in agreement with other studies finding species specific effects of multiple stressors3031, suggesting that the exact effects of interactions depend on the experimental setup, as well as on the species investigated. This highlights the potential problems of extrapolating results from studies investigating interactions on one species to, e.g., community scale or to ecological risk assessments12, and thereby emphasizing the need for further studies using standardised methods and/or multiple species. Interestingly, we found that the effects of the different treatments on composite performance were largely similar in the two species (Table 1), albeit highly variable between treatments.…”

“…This may result in underestimating the effect of multiple environmental factors on population persistency and the stability of communities4, a risk exemplified by the combination of thermal extremes and drought stress resulting from climate change10. The predictability and generalizability of responses to multiple environmental factors should be incorporated in general global climate change models11, and in ecological risk assessments212 for increased accuracy and prediction power of community assembly modelling6.…”