Dormancy in Pacific sand lance, Ammodytes personatus, may serve as a partial buffer against negative impacts of anthropogenic noise

Anthropogenic noise continues to increase every year. While noise has several negative effects on fish, few studies have addressed noise effects on forage fish - a group of key species in their ecosystems. Pacific sand lance, Ammodytes personatus (PSL), are a key forage fish and food source in the Northeastern Pacific Ocean. Research suggests that PSL in noisy compared to quiet environments are of poorer quality, potentially impacting their marine predators - especially marine birds that rely on them in the spring and summer. However, unlike other forage fish, PSL go dormant for several months during the food-scarce fall and winter to conserve energy and avoid predation. For breeding age fish, this is also the time in which they develop their gonads before spawning. While some aspects of dormancy have been studied (e.g., eating cessation) many gaps remain in our understanding of how other factors (e.g., oxygenation, stress) affect survival and emergence condition. We ask if dormancy in PSL a) buffers (e.g., if suppressed metabolism reduces physiological effects of stress), or b) exacerbates (e.g., increase stress changing the critical threshold necessary to survive dormancy) the effects of anthropogenic noise. To test this, we held fish in different acoustic environments for 10 weeks and measured their quality. We found that energy density didn't change among acoustic environments, but noise affected the weight-length relationship of non-breeding fish but not breeding fish. This suggests that dormancy may partially buffer breeding PSL but non-breeding fish may be susceptible to the effects of anthropogenic noise.