Meeting Abstract
Over the last few decades, underwater anthropogenic noise has increased ambient sound levels by >30dB in the range that most fishes detect and produce acoustic signals. Despite known effects on acoustic signaling, it remains largely unknown how social fishes cope with anthropogenic noise. In the territorial African cichlid fish Astatotilapia burtoni, social status is tied to reproductive success and is dependent on a male’s ability to obtain and defend a spawning territory. Males use agonistic behaviors that generate water movements, which can stimulate the mechanosensory and auditory systems of nearby fish, but these signals may be masked by increased background noise. By observing territorial interactions in silent and noise playback conditions, we examined how high background noise impacts agonistic interactions in this highly territorial and social fish. During noisy conditions, fish had an increased latency to fight, and fights occurred in bouts instead of a single fight. Although the total time spent fighting did not differ, the increased time to resolution of the territorial dispute can have consequences on the energy expenditure and predation risk of fish. This altered fight structure may indicate that fish were distracted by the noise or had increased stress levels. Interestingly, fish fighting in noisy conditions appeared more brightly colored and spent more time with their eyebar displayed than those in silent conditions, suggesting an increase in visual signaling due to disruption in other sensory channels. To our knowledge, this is one of the first studies to examine how anthropogenic noise impairs social behaviors in a site-attached, soniferous fish species. As such, these results have important conservation and management implications for protecting against noise-induced effects on territoriality and reproductive success.
