Underwater Sound Recording and Marine Acoustic Ecology Research
Waterways are a cacophonous blend of marine animal sounds, as sound travels quickly over long distances in water, making sound an efficient means for marine life to know each other and their surroundings. Today, these waterways are also full of human-made sounds that can emit disruptive noise in an aquatic acoustic ecology, and oysters, like many species, are affected.
Oysters’ bodies are extremely viscous, and close to the density of water, a quality that makes them extremely sensitive to sound. (Charifi et. al. 2017) Oysters need their seabeds to have certain conditions to settle and reproduce, and they identify these areas by distinguishing sound signatures in underwater soundscapes. In fact, oysters are highly acoustically perceptive and are drawn to distinct soundscapes that signal healthy reefs to settle in. (Eggleston et al 2016) They seek frequencies in the 1–2-kHz range, which indicates an ideal acoustic ecology that includes sounds of toadfish and snapping shrimp, among other marine organisms that call a healthy oyster reef habitat home. Given this phenomenon, it’s speculated that the onset of noise from cargo, passenger and recreational marine traffic disrupts oysters’ settling process. For instance, marine traffic may mask sound signatures that indicate safe habitats. In addition, studies found that oysters are sensitive to low frequency sine tones that range from 10 – 200Hz. Since their valves close at the onset of these frequencies, it’s also posited that ships that emit frequencies in this range, at loud amplitudes, may disrupt their reproductive and filtering process. (Charifi et. al. 2017)
To work through this research, we investigated the soundscapes of three reef restoration sites in New York’s East River, established by the Billion Oyster Project, a NYC-based nonprofit working to ecologically restore the city’s waterways through oyster repopulating initiatives. Using hydrophones, we recorded data at sites in the Williamsburg Field Station, including the Bushwick Inlet and North 5th Street Pier, and in Manhattan at the East 90th Street Ferry Terminal. Each station had unique sonic qualities and shared acoustic features.
Big thanks to BOP team Agata Poniatowski, Robina Taliaferrow and Chris.
Our goal was to document soundscapes of selected habitats, determine possible disruption caused by human induced noise, establish reference points for future comparison, and gather field recordings for the installation, Serenades for Settling. Each station had unique sonic qualities and shared acoustic features. Following are sound samples from the sites.
North 5th Street Pier Sample #1, Williamsburg, NY, recorded June 8, 2022 12:29pm
In this sound sample we hear water and waves against the pier and toad fish. Most prominent is the sound of a NYC ferry as it berths at the adjacent pier, where the North Williamsburg ferry terminal is located. The sound of the ferry as it hits wooden pilings at 0:35 in the recording is particularly note worthy.
East 90th Street Ferry Terminal Sample #2, Manhattan, NY, recorded June 8, 2022 4:10pm
In this sound sample we hear a NYC ferry as it departs from the adjacent terminal. Listen for a sudden break in audible intensity as the ferry briefly cuts its engines at 0:03 and 0:28 in the recording. During those breaks we hear water flowing, air bubbles popping and a resonant drone from an unidentified source, which is the sites soundscape baseline.
Bushwick Inlet Sample #4, Williamsburg, NY, recorded June 7, 2022 @ 10:38am
In this sound sample we hear water flowing within the inlet, air bubbles popping, toad fish, and a NYC ferry as it passes by. The ferry was about 2500 feet away from our recording location in the inlet. You can hear the peak of its passing at about 0:25 in the recording. Also audible are waves caused by the ferry passing, and a rope as it rubs against the rocking dock, agitated by waves.
D.B. Eggleston, A. Lillis, D.R. Bohnenstiehl, “Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds,” in The Effects of Noise on Aquatic Life II. Advances in Experimental Medicine and Biology, eds. A. Popper, A. Hawkins (eds) vol 875 (2016). Springer, New York, NY. https://doi.org/10.1007/978-1-4939-2981-8_30
M Charifi, M Sow, P Ciret, S Benomar, J-C Massabuau, “The sense of hearing in the Pacific oyster,”, Magallana gigas, PLoS ONE 12(10) (2017): e0185353. Accessed February 12, 2022, https://doi.org/10.1371/journal.pone.0185353