Multiscale spatio-temporal patterns of boat noise on U.S. Virgin Island coral reefs

Abstract

Sound-sensitive organisms are abundant on coral reefs. Accordingly, experiments suggest that boat noise could elicit adverse effects on coral reef organisms. Yet, there are few data quantifying boat noise prevalence on coral reefs. We use long-term passive acoustic recordings at nine coral reefs and one sandy comparison site in a marine protected area to quantify spatio-temporal variation in boat noise and its effect on the soundscape. Boat noise was most common at reefs with high coral cover and fish density, and temporal patterns reflected patterns of human activity. Boat noise significantly increased low-frequency sound levels at the monitored sites. With boat noise present, the peak frequencies of the natural soundscape shifted from higher frequencies to the lower frequencies frequently used in fish communication. Taken together, the spectral overlap between boat noise and fish communication and the elevated boat detections on reefs with biological densities raises concern for coral reef organisms.

Listening forward: approaching marine biodiversity assessments using acoustic methods

“…Separation of these three contributors should be an initial step of any soundscape evaluation. Some analyses may aim to assess and compare the overall soundscape contributions of biological and anthropogenic sounds [ 123 , 124 ], or to assess the influence of abiotic sounds (e.g. wind and wave noise) on biological functions [ 125 ].…”

Monitoring of a Nearshore Small Dolphin Species Using Passive Acoustic Platforms and Supervised Machine Learning Techniques

“…The models were fitted using the R package "mgcv" (R Core Team, 2019; Wood, 2019), and the splines library was used to build cyclic cubic regression splines (Wood, 2017). Knots were capped at four smooths following the method described by Dinh et al (2018). The number of clicks recorded during the entire day and night phase was also inspected, based on the mean time of sunrise and sunset in the study area (25 February-10 May; sunrise: 07:02, sunset: 18:26; acquired from the Time and Date AS website 1 ).…”

Assessing anthropogenic noise impacts and relevant soundscape cues for marine invertebrates: leveraging squid and coral reefs as model systems

“…Predominant coral reef sounds within their hearing ranges include abiotic sounds from wind and wave motion, often below 100 Hz, and sounds produced by fish, often below 1000 Hz (Montgomery et al, 2006;Tricas & Boyle, 2014). Anthropogenic boat noise is also in this frequency range, and is present daily in many nearshore habitats, including coral reefs (Butler et al, 2021;Dinh et al, 2018). Broadband choruses of snapping shrimp snaps are omnipresent in many coral reef soundscapes, and usually have peak frequencies at or above 2000 Hz (Au & Banks, 1998;.…”

“…The presence and influences of anthropogenic sounds on coral reefs are also important to understand. Noise from recreational vessels and commercial shipping is frequent in many coastal habitats, including coral reefs (Bittencourt et al, 2020;Dinh et al, 2018;. Boat noise can have a multitude of adverse effects on invertebrates and fishes, such as physiological changes indicative of stress (Filiciotto et al, 2016), disruptions to feeding, antipredator, settlement, or orientation behaviors (Bruintjes et al, 2016;Holles et al, 2013;Magnhagen et al, 2017;Mensinger et al, 2018;Simpson et al, 2016;Wale et al, 2013a), and masking of ecologically relevant cues (Pine et al, 2016).…”

“…These reefs have been the focus of ecological research for decades (Edmunds, 2013;Edmunds et al, 2020). Recent studies focusing on sound pressure have investigated multiple facets of soundscape ecology at these sites, including temporal variability , across-reef spatial variability (Lillis, Caruso, et al, 2018), patterns in snapping shrimp activity , settlement behavior of corals (Lillis, Apprill, et al, 2018), larval fish settlement (Suca et al, 2020), and boat noise patterns (Dinh et al, 2018;. These studies provide valuable observations based on sound pressure, with which we can compare trends in particle motion data.…”