Noise Affects Multimodal Communication During Courtship in a Marine Fish

Abstract

Selection pressures on signals can be substantially modified by a changing environment, but we know little about how modified selection pressures act on multimodal signals. The currently increasing levels of anthropogenic noise in the ocean may affect the use of acoustic signaling relative to other modalities. In the Painted Goby (Pomatoschistus pictus), visual and acoustic signals are associated during courtship behavior, but females usually rely more heavily on acoustic signals than on visual signals in mate choice. In an aquarium experiment, we compared male courtship behavior and female spawning decisions between silent treatments and treatments with additional noise. We found that the relationships between male characteristics, male visual and acoustic courtship, and spawning success were affected by noise. A path analysis revealed that females pay more attention to visual courtship in noisy circumstances compared to control. We conclude that environmental stressors can cause shifts in the use of different signaling modalities for spawning decisions and discuss how selection pressures on multimodal signals may change with increasing noise-levels.

Passive acoustic monitoring shows no effect of anthropogenic noise on acoustic communication in the invasive round goby (Neogobius melanostomus)

“…We found no behavioural effects by our measure even with heavy boating activity and noise levels in excess of 140 dB re: 1 μPa, suggesting that round goby calling is unlikely to be affected by moderate levels of anthropogenic noise. Previous research in laboratory settings also finds little effect of prolonged sound exposure on pressure‐insensitive species for hearing ability (Scholik & Yan, ; Smith, Kane, & Popper, ; Wysocki, Amoser, & Ladich, ) or even overall health (Wysocki, Davidson, et al., ), although De Jong, Amorim, Fonseca, Fox, and Heubel () and De Jong, Amorim, Fonseca, and Heubel () do show changes in signalling displays and spawning success in laboratory sound exposures on other gobiids. Sound exposure guidelines are critically needed for underwater environments (Hawkins & Popper, ; Hawkins et al., ; Nolet, ; Popper et al., ) and have been developed for pressure‐sensitive fish species (Popper et al., ).…”

“…While there is good evidence for noise effects in marine systems (Hawkins & Popper, ), there is much less evidence of noise effects in freshwater systems based on field studies (Desjonquères et al., ; Mickle & Higgs, ). In laboratory studies, increased noise levels can affect calling rate in other gobiid species (De Jong, Amorim, Fonseca, Fox, & Heubel, ; De Jong, Amorim, Fonseca, & Heubel, ) and noise may affect spawning success of gobiids using acoustic modalities (De Jong, Amorim, Fonseca, Fox, & Heubel, ; De Jong, Amorim, Fonseca, & Heubel, ). While it is difficult to equate laboratory acoustic experiments to field settings (Popper & Hawkins, ) it may be that the sound exposures in our current study were lower than those in the De Jong, Amorim, Fonseca, Fox, and Heubel () and De Jong, Amorim, Fonseca, and Heubel () laboratory studies so we may still see effects in the field at higher intensities.…”

“…In laboratory studies, increased noise levels can affect calling rate in other gobiid species (De Jong, Amorim, Fonseca, Fox, & Heubel, ; De Jong, Amorim, Fonseca, & Heubel, ) and noise may affect spawning success of gobiids using acoustic modalities (De Jong, Amorim, Fonseca, Fox, & Heubel, ; De Jong, Amorim, Fonseca, & Heubel, ). While it is difficult to equate laboratory acoustic experiments to field settings (Popper & Hawkins, ) it may be that the sound exposures in our current study were lower than those in the De Jong, Amorim, Fonseca, Fox, and Heubel () and De Jong, Amorim, Fonseca, and Heubel () laboratory studies so we may still see effects in the field at higher intensities. Long‐term exposure to motorboat noise in brackish waters had no effect on the stress response of Eurasian perch ( Perca fluviatilis ) and roach ( Rutilus rutilus ; Johansson, Sigray, Backström, & Magnhagen, ), although short‐term ship noise exposure did elevate metabolic oxygen demand in European eels ( Anguilla anguilla ) in a field setting (Simpson, Purser, & Radford, ) and there are numerous reports of fish avoiding noise generated by larger ships in the field (Handegard, Michalsen, & Tjøstheim, ; Mitson & Knudsen, ; Vabø, Olsen, & Huse, ).…”

“…Anthropogenic noise is a known ecological stressor in many aquatic habitats (Mickle & Higgs, ; Popper & Hawkins, ) and the levels of noise continue to increase in both marine and freshwater habitats (Frisk, ; Slabbekoorn et al., ). The main driver of increases in anthropogenic noises is boat and ship noise (Frisk, ) and these have been shown to induce behavioural effects in at least some fish species (De Jong, Amorim, Fonseca, Fox, & Heubel, ; De Jong, Amorim, Fonseca, & Heubel, ; De Robertis & Handegard, ; Engås, Misund, Soldal, Horvei, & Solstad, ; Picciulin, Sebastianutto, Codarin, Farina, & Ferrero, ; Sarà et al., ). All fish tested to date can detect the particle motion component of sound waves, especially predominant at frequencies below approximately 800 Hz close to the sound source (Popper & Hawkins, ), but to detect the pressure component of sound, fish must have evolved some specialised relationship between a gas‐filled structure and the ear to change the pressure waves into particle displacement (Schulz‐Mirbach & Ladich, ).…”

Ecology of sound communication in fishes

“…This is opposite to the expected behaviour and undermines the hypothesis that signalling fish compensate the loss in acoustic information by other signal modalities. While there is no evidence of compensation on the part of the male sender, female receivers paid more attention to visual courtship signalling in the noise experiments (sensory compensation hypothesis; Partan, ; De Jong, Amorim, Fonseca, & Heubel, ). This is because the females probably did not perceive male courtship calls at all due to masking of their already low hearing abilities (Lugli & Fine, ).…”