Continuous but not intermittent noise has a negative impact on mating success in a marine fish with paternal care

Anthropogenic underwater noise is a global pollutant of increasing concern but its impact on reproduction in fish is largely unknown. Hence, a better understanding of its consequences for this important link to fitness is crucial. Working in aquaria, we experimentally tested the impact of broadband noise exposure (added either continuously or intermittently), compared to a control, on the behaviour and reproductive success of the common goby (Pomatoschistus microps), a vocal fish with exclusive paternal care. Compared to the intermittent noise and control treatments, the continuous noise treatment increased latency to female nest inspection and spawning and decreased spawning probability. In contrast, many other female and male pre-spawning behaviours, and female ventilation rate (proxies for stress levels) did not differ among treatments. Therefore, it is likely that female spawning decisions were delayed by a reduced ability to assess male acoustic signals, rather than due to stress per se and that the silent periods in the intermittent noise treatment provided a respite where the females could assess the males. Taken together, we show that noise (of similar frequency range as anthropogenic boat noise) negatively affects reproductive success, particularly under a continuous noise exposure.Financial support was provided by the Graduate School in Marine Environmental Research at the Gothenburg Centre for Marine Research, Helge Ax:son Johnssons stiftelse, Herbert & Karin Jacobssons stiftelse, Wilhem och Martina Lundgren, Rådman och Fru Ernst Collianders stiftelse (to E.L.B.), Linneus Centre for Marine Evolutionary Biology (to O.S. and C.K.), Fundação para a Ciência e Tecnologia (FCT), through the strategic project UID/MAR/04292/2019 granted to MARE (to M.C.P.A.) and the Swedish Research Council (to C.K.).