Researchers and fisheries managers who use acoustic telemetry to tag and track fish know of all the challenges involved. Fish tagging costs time and money, and the range that these tags can be detected changes with the environment.
Findings in a new paper, led by UGA Skidaway Institute of Oceanography PhD student Frank McQuarrie, seek to help those using acoustic telemetry know when and where their equipment will be most successful, increasing their abilities to estimate the probability of detection and the effective range of their instruments.
McQuarrie found that wind speed has a direct relationship on the effectiveness of acoustic telemetry devices on Georgia’s coastal reefs. During storms, his team’s receivers were able to detect high-frequency transmissions from tagged fish to receivers far more often.
This discovery adds to past research, which has shown that detections are impacted by the tides, moon cycles, and seasons, among other environmental changes.
“We saw that, at high wind speed, when there were crashing waves, we could hear much better. We heard more detections, which we didn’t expect,” said McQuarrie.
Uniquely, a big piece in this equation is the snapping shrimp.
Snapping shrimp, which are common in coastal reefs, are the top interferers with acoustic telemetry, as they are some of the only animals that make noise at frequencies high enough for receivers to pick up. Their constant snapping can drown out the signals sent from tagged fish to receivers.
However, McQuarrie found that during storms, waves crash and create bubble layers that absorb the sounds caused by snapping shrimp, allowing high-frequency sounds sent from transmitters attached to fish to pass through and more effectively reach receivers.
McQuarrie calculated the noise lost to the surface and created an algorithm to demonstrate that winds don’t lower shrimp activity.
“Why should people care? Because fish tagging can be expensive, you should know when and where it will be successful,” said McQuarrie. “Fisheries managers and researchers need to estimate the probability of detection and the effective range of these instruments. My work helps inform those efforts.”
The full paper, titled A Reef’s High-Frequency Soundscape and the Effect on Telemetry Efforts: A Biotic and Abiotic Balance, is published in the Journal of Marine Science and Engineering.
About SkIO
The UGA Skidaway Institute of Oceanography (SkIO) is a multidisciplinary research and education institution located on Skidaway Island near Savannah, Georgia. The Institute was founded in 1967 with a mission to conduct research in all fields of oceanography. In 2013, SkIO was merged with the University of Georgia. The campus serves as a gateway to coastal and marine environments for programs throughout the University System. The Institute’s primary goals are to further the understanding of marine and environmental processes, conduct leading-edge research on coastal and marine systems, and train tomorrow’s scientists. For more information, visit www.skio.uga.edu.