Date of Award

2021

Degree Type

Thesis

Degree Name

Master of Science in Biological and Environmental Sciences (MSBES)

Department

Biological Sciences

First Advisor

Andrew J. Davies

Abstract

Sentinel indicators are quantifiable variables that are sensitive to environmental changes and represent a key component or process of the ecosystem being monitored. In this study, we explored whether a sentinel monitoring approach, based on passive acoustic recordings, could shed light on specific environmental and oceanographic conditions within deep-sea habitats. Passive acoustics can capture rich multidimensional information about ecosystems, including local and distant events and natural or anthropogenic activities, using a single instrument. A benthic lander collected data for three months from April 2019 at a cold-water coral reef known as the Richardson Reef Complex (Southeast USA). In addition to several environmental sensors, a hydrophone passively recorded acoustic frequencies between 10 Hz and 64 kHz. The strength of associations between sound level and environmental variables were assessed with general additive models and showed significant relationships between sound levels and horizontal current velocity, vertical current velocity, and turbidity. Changepoint analysis identified significant shifts in environmental and acoustic data that revealed the substantial signature of the Gulf Stream on the soundscape at Richardson Reef, as current-driven sound levels increased. While passive acoustic recordings of the deep sea have not previously been used to provide information about current dynamics, we show their significant potential for monitoring variability of abiotic environmental parameters in logistically challenging environments.

Available for download on Friday, January 05, 2024

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