What’s all that racket! Soundscapes, phenology, and biodiversity in estuaries

during spring of 2017 was the highest (i.e. + 1.21˚C than the 6 year average) of all 6 years moni- tored (S3 Table). On the other hand, the mean spring temperature in 2013 was the lowest (i.e. -1.33˚C than the 6 year average), and the first peak in snapping shrimp acoustic activity was detected 9 days later than the 6 year average at station 9M, while fish acoustic activity was detected 4 days later. We found similar patterns at stations 14M and 37M (S3 and S4 Tables). We found negative correlations between mean spring water temperature and the timing of the first peak in probability of change for high, low, and broadband SPLs at stations 9M and 14M (Fig 3D–3F). In addition, during the winter of 2017–2018, we recorded the lowest, minimum water temperature and the lowest SPL values of all three winters monitored (Figs 1 and 2). During the spring 2018, the first peak in SPL was detected later than in the years with higher winter and spring tempera- tures (S3 and S4 Tables). In the years with higher fluctuations in spring water temperature, there were more abrupt changes in SPLs (S5–S13 Figs). Soundscape and biodiversity We used haul seines to estimate species richness, the Shannon-Wiener diversity index, and total abundance of species in the May River estuary between 2016 and 2018. In total, we caught Fig 3. Relationship between mean spring water temperature and day of year of first Posterior Probability (PP) of change � 0.5. Left panels: lines with dots represent day of year of first PP � 0.5 of sound pressure level in (A) high

(7000–40,000 Hz), (B) low (50–1200 Hz), and (C) broadband (1–40,000 Hz) frequency range, while lines with squares represent mean spring water temperature at stations 9M and 14M. Right panels: relationship between mean spring water temperature and day of year of first PP � 0.5 of sound pressure level in (D) high (7000–40,000 Hz), (E) low (50– 1200 Hz), and (F) broadband (1–40,000 Hz) frequency range with corresponding mean spring water temperature at stations 9M and 14M. This dataset did not contain files with physical sounds and anthropogenic noise. https://doi.org/10.1371/journal.pone.0236874.g003 PLOS ONE Estuarine soundscapes and biodiversity PLOS ONE | https://doi.org/10.1371/journal.pone.0236874 September 3, 2020 5 / 18