Low-amplitude noise elicits the Lombard effect in plainfin midshipman mating vocalizations in the wild

Boat noise impacts Lusitanian toadfish breeding males and reproductive outcome

“…The only study that has thus far evaluated the effect of boat noise on reproductive success in situ showed that the oyster toadfish Opsanus tau, nesting in areas with real motorboat noise exposure had lower reproductive success as more nests had no egg clutches or the number of embryos per clutch was significantly lower than in quiet areas (Krahforst, 2017), consistent with the present study. In contrast, Brown et al (2021) did not find an effect of exposure to artificial tonal noise on reproductive success in the plainfin midshipman fish in the field.…”

“…Males in the boat noise treatment showed a continued depressed calling activity compared to control males. A detrimental effect in calling activity has been found in other batrachoidids namely the oyster toadfish (Krahforst, 2017;Mackiewicz et al, 2021) and the plainfin midshipman (Brown et al, 2021), in sciaenids such as the black drum Pogonias courbina (Ceraulo et al, 2021) and the meagre Argyrosomus regius (Vieira et al, 2021c), and in two gobies, Gobiusculus flavescens and P. pictus (de Jong et al, 2018a). Besides from decreasing calling activity, which is essential to attract and court mates in several fish species (Amorim et al, 2015), reproduction may be further impaired by the reduction in the communication active space (Alves et al, 2016), by masking (Alves et al, 2021;Pine et al, 2021) or changing the receivers' physiology by causing stress and/or distraction (Simpson et al, 2016;Butler and Maruska, 2021).…”

“…Besides from decreasing calling activity, which is essential to attract and court mates in several fish species (Amorim et al, 2015), reproduction may be further impaired by the reduction in the communication active space (Alves et al, 2016), by masking (Alves et al, 2021;Pine et al, 2021) or changing the receivers' physiology by causing stress and/or distraction (Simpson et al, 2016;Butler and Maruska, 2021). Interestingly, some species compensate for communication loss by increasing vocalization rates (such as the brown meagre Sciaena umbra; Picciulin et al, 2012), by changing the frequency and/or amplitude of their vocalizations (Brown et al, 2021), or by shifting to other sensory modalities (de Jong et al, 2018b).…”

“…In a recent study, de Jong et al (2020) showed that underwater noise, particularly boat noise, has a high likelihood to impact different stages of reproduction such as sexual maturation, establishment of spawning grounds, spawning success and hatching success. Yet, very few studies have addressed the impact of anthropogenic noise on fish reproduction especially in the natural environment, either freshwater or marine (courtship behaviour -Krahforst, 2017;Brown et al, 2021;clutch number and size -Krahforst, 2017;parental care -Nedelec et al, 2017;Maxwell et al, 2018;offspring survival -Nedelec et al, 2017;Faria et al, 2022). To date, only two studies have assessed the impact of boat noise on reproductive outcome in marine fish in situ, and both found deleterious effects (Krahforst, 2017;Nedelec et al, 2017).…”

Sound production and mechanism in the cryptic cusk‐eelParophidion vassali

“…Birds, mammals and frogs may increase the amplitude of their signals in order to elevate the signal‐to‐noise ratio of their call relative to background noise, a phenomenon referred to as the Lombard effect (Harlan & Bernard, 1971; Lopez et al, 1988; Oliveira & Canário, 2000). This ability is known in few fish species only (Brown et al, 2021; Holt & Johnston, 2014; Luczkovich et al, 2016). Although P. vassali are quite small (no more than 20 cm and 15 gr), they produce loud sounds, up to 137 dB, indicating that their sounds should be easily detected in the soundscape.…”