Repeated exposure reduces the response to impulsive noise in European seabass

Abstract

Human activities have changed the acoustic environment of many terrestrial and aquatic ecosystems around the globe. Mounting evidence indicates that the resulting anthropogenic noise can impact the behaviour and physiology of at least some species in a range of taxa. However, the majority of experimental studies have considered only immediate responses to single, relatively short‐term noise events. Repeated exposure to noise could lead to a heightened or lessened response. Here, we conduct two long‐term (12 week), laboratory‐based exposure experiments with European seabass (Dicentrarchus labrax) to examine how an initial impact of different sound types potentially changes over time. Naïve fish showed elevated ventilation rates, indicating heightened stress, in response to impulsive additional noise (playbacks of recordings of pile‐driving and seismic surveys), but not to a more continuous additional noise source (playbacks of recordings of ship passes). However, fish exposed to playbacks of pile‐driving or seismic noise for 12 weeks no longer responded with an elevated ventilation rate to the same noise type. Fish exposed long‐term to playback of pile‐driving noise also no longer responded to short‐term playback of seismic noise. The lessened response after repeated exposure, likely driven by increased tolerance or a change in hearing threshold, helps explain why fish that experienced 12 weeks of impulsive noise showed no differences in stress, growth or mortality compared to those reared with exposure to ambient‐noise playback. Considering how responses to anthropogenic noise change with repeated exposure is important both when assessing likely fitness consequences and the need for mitigation measures.

Anthropogenic noise alters dwarf mongoose responses to heterospecific alarm calls

“…Chan et al, 2010;Meillère et al, 2015;Simpson et al, 2015Simpson et al, , 2016Shannon et al, 2016). Longer-term studies are needed to consider such aspects as compensation and changing responses (Bejder et al, 2009), because individuals may become more or less tolerant with repeated exposure (Scholik and Yan, 2001;Wale et al, 2013b;Radford et al, 2016). In terms of vocalisations, there is evidence that anthropogenic noise could lead to signallers adjusting acoustic parameters plastically (Patricelli and Blickley, 2006;Templeton et al, 2016) or alterations occurring across generations (Slabbekoorn and Ripmeester, 2008;Lowry et al, 2012), to improve the effectiveness of communication.…”

The impact of experimental impact pile driving on oxygen uptake in black seabream and plaice

“…The increased oxygen uptake suggests heightened stress during exposure to pile driving (Barton, 2002). Other species, such as European eels (Anguilla anguilla) and European sea bass also increased oxygen uptake when exposed to playback of anthropogenic sounds Radford et al, 2016), whereas an in situ pile driving study using European sea bass found a decrease in oxygen uptake (Debusschere et al, 2016).…”

Mitigation provisions to be implemented for marine seismic surveying in Latin America: a review based on fish and cetaceans

“…The signals produced by seismic surveying have been documented to cause some fish to flee (Fewtrell & McCauley 2012), although the response to impulsive noise is reduced after repeated exposure (Radford et al 2016). Seismic signals can elicit a startle response in coral reef fishes (Boeger et al 2006) and a change in their swimming pattern, whereby individuals move to the bottom of the water column and swim faster in tighter groups (Pearson et al 1992, Fewtrell & McCauley 2012, Neo et al 2015; the latter behavior is also called atypical mass stranding in squids (Guerra et al 2004(Guerra et al , 2011.…”

“…Respiration and oxygen con-sumption rates have been used as measures of direct physiological response in fish (Radford et al 2016), cephalopods (Kaifu et al 2007), and lobsters (Filiciotto et al 2014). As an example, European seabass exposed to playbacks of recordings of pile-driving and seismic surveys exhibited increased ventilation rates in relation to control individuals exposed to ambient-noise playback (Radford et al 2016).…”

“…Respiration and oxygen con-sumption rates have been used as measures of direct physiological response in fish (Radford et al 2016), cephalopods (Kaifu et al 2007), and lobsters (Filiciotto et al 2014). As an example, European seabass exposed to playbacks of recordings of pile-driving and seismic surveys exhibited increased ventilation rates in relation to control individuals exposed to ambient-noise playback (Radford et al 2016). Meanwhile, adrenaline and cortisol rates (Sverdrup et al 1994, Santulli et al 1999, heat shock proteins, as well as immune responses have been used as indirect measures of physiological response; these responses may lead to an energy trade-off and thus influence survival and reproduction.…”