The oyster toadfish ( <i>Opsanus tau</i> ) alters active and diurnal calling amid vessel noise in New York City

While many studies have demonstrated the negative impacts of anthropogenic noise on aquatic animals, few studies have examined its effect on species that inhabit major ports. New York City provides habitat for the oyster toadfish (Opsanus tau), a species in which females must hear the male advertisement call to reproduce. This study had two equally important goals. First, vessel noise in the waters of New York City was characterized: An analysis of 480 vessel noise events revealed that noise incidence varied widely, while amplitude varied less. Second, toadfish calling behavior was quantified under noisy and quiet conditions. Toadfish called over twice as much in quiet samples, which occurred in the early morning, than in samples with noise. This early morning peak in calling behavior differs from those of non-urban populations and is evidence of diurnal call suppression. Furthermore, in samples with noise, toadfish actively called less when noise duration was longer, amplitude was greater, and the dominant frequency of noise overlapped the fundamental frequency of calls. Finally, toadfish did not change call amplitude, frequency or duration during noise. These results provide evidence that fishes living in vessel-heavy urban environments adjust their reproductive-related acoustic communication behavior to cope with noise.