https://www.selleckchem.com/products/n-ethylmaleimide-nem.html Anthropogenic noise sources range from intermittent to continuous, with seismic and navy sonar technology moving towards near-continuous transmissions. Continuous active sonar (CAS) may be used at a lower amplitude than traditional pulsed active sonar (PAS), but potentially with greater cumulative sound energy. We conducted at-sea experiments to contrast the effects of navy PAS vs. CAS on sperm whale behaviour using animal-attached sound and movement-recording tags (n=16 individuals) in Norway. Changes in foraging effort and proxies for foraging success and cost during sonar and control exposures were assessed while accounting for baseline variation (individual effects, time of day, bathymetry and blackfish [pilot/killer whale] presence) in generalized additive mixed models. We found no reduction in time spent foraging during exposures to medium-level PAS (MPAS) transmitted at the same peak amplitude as CAS. In contrast, we found similar reductions in foraging during CAS (df=1, F=8.0, p=0.005) and higher amplitude PAS (df=1, F=20.8, p less then 0.001) when received at similar energy levels integrated over signal duration. These results provide clear support for sound energy over amplitude as the response driver. We discuss the importance of exposure context and need to measure cumulative sound energy to account for intermittent vs. more continuous sources in noise impact assessments. © 2020. Published by The Company of Biologists Ltd.Organisms with wide environmentally-induced morphological plasticity and cosmopolitan distribution, e.g., the common freshwater rotifer Keratella cochlearis, are ideal models to study the evolution of plastic polymorphisms and the capacity of zooplankton to adapt to local selection conditions. We investigated population-level differences (population-by-environment interaction) in sensitivity to food availability and temperature-induced phenotypic plasticity between two clone