Monitoring spatial and temporal soundscape features within ecologically significant U.S. National Marine Sanctuaries

Abstract

The U.S. National Oceanic and Atmospheric Administration’s Office of National Marine Sanctuaries manages a system of marine protected areas encompassing more than 2,000,000 km2. U.S. National Marine Sanctuaries (NMS) have been designated to provide protection for their conservation, recreational, ecological, historical, scientific, cultural, archaeological, educational, or aesthetic qualities. Due to the large variability of attributes among NMS, designing coordinated system‐wide monitoring to support diverse resource protection goals can be challenging. Underwater sound monitoring is seeing increasing application to marine protected area management because it is able to support this wide variety of information needs. Passive acoustics are providing invaluable autonomous information regarding habitat associations, identifying species spatial and temporal use, and highlighting patterns in conditions that are otherwise difficult to survey. Using standardized equipment and analysis methods this study collected ambient underwater sound data and derived measurements to investigate temporal changes in sound pressure levels and power spectral density, identify presence of select species of importance and support within and among site comparison of ambient underwater sound among eight sites within four U.S. NMS. Broadband sound pressure levels of ambient sound (10–24,000 Hz) varied as much as 24 dB re 1 µPa (max difference 100–124 dB re 1 µPa) among the recording sites, sanctuaries, and seasons. Biotic signals, such as snapping shrimp snaps and vocalizations of fishes, exhibited distinct diel and seasonal patterns and showed variation among sites. Presence of anthropogenic signals, such as vessel passage, also varied substantially among sites, ranging from on average 1.6–21.8 h/d. The study identified measurements that effectively summarized baseline soundscape attributes and prioritized future opportunities for integrating non‐acoustic and acoustic variables in order to inform area‐specific management questions within four ecologically varying U.S. National Marine Sanctuaries.

Sounding the Call for a Global Library of Underwater Biological Sounds

“…PAM is already used for a multitude of biological applications. Examples include monitoring, characterizing and delineating underwater soundscapes, and investigating aquatic communities (e.g., Desjonquères et al, 2015;Erbe et al, 2015;Menze et al, 2017;Mooney et al, 2020;Stanley et al, 2021); documenting the distribution and migration patterns of the great whales (e.g., Risch et al, 2014;Tsujii et al, 2016;Davis et al, 2020;Warren et al, 2021); characterizing the spatial and temporal responses of fish choruses to environmental drivers like temperature, salinity, lunar phase, tide, and time of sunset (e.g., Barrios, 2004;Rountree et al, 2006;Parsons, 2010;Straight et al, 2015;Rice et al, 2016;McWilliam et al, 2017;Parsons et al, 2016;Karaconstantis et al, 2020;Linke et al, 2020); understanding how animals change their behavior and distribution in response to climate change (Gordon et al, 2018), anthropogenic noise sources (e.g., Thompson et al, 2013;Cerchio et al, 2014;Erbe et al, 2019;Meekan et al, 2021), algal blooms (e.g., Rycyk et al, 2020) and extreme weather events like hurricanes (e.g., Locascio and Mann, 2005;Fandel et al, 2020;Boyd et al, 2021;Schall et al, 2021); understanding how prey change their sound production rates or behaviors with the presence of predators (e.g., Luczkovich and Keusenkothen, 2007;Hughes et al, 2014;Bailey et al, 2019;Burnham and Duffus, 2019); and how noise and propagation conditions can affect communication spaces (e.g.,…”