Valeria Elena González Borasca

Soundscape Analysis on a Humpback Whale (Megaptera novaeangliae) Breeding Ground in the Northern Colombian Pacific

Humpback whales annually migrate between feeding and breeding areas. Specifically, Stock G uses the waters of the Colombian Pacific, and specifically the Gulf of Tribugà, to mate and calve between June and October of each year. The acoustic communication system of the humpback whale relies on an individual’s ability to establish and maintain contact with conspecifics across vast and proximate distances. Noise from industrial, commercial, and tourism activities that support the livelihood of local communities in the Gulf of Tribugá could mask critical communications for whales to find, mate with, and protect one another.

This project is a replication of Dr. Seger`s 2016 dissertation research in Baja California, Mexico, to map the soundscape in an effort to track the influence of biotic and abiotic acoustic levels. To obtain acoustic data, two battery-operated Ecological Acoustic Recorders (EARs) using HTI-96-MIN (High Tech Inc.) hydrophones with -171 dB re 1V/Pa sensitivity, have been deployed in two areas of the Gulf of Tribugá: one in Nuquí, which represents an area exposed to noise pollution from fishing and tourism boats, and the other in Morro Mico, which represents a more pristine acoustic environment with little anthropogenic noise. The EARs will remain underwater from mid-July to mid-September 2018. Once the hydrophones are recovered, acoustic data will be processed using an in-house Matlab GUI written by Drs. Aaron Thode, Jit Sarkar, and Kerri Seger. Power spectral densities (PSDs) will be computed in dB re 1 μPa2/Hz and estimated to 3-Hz resolution each minute, by averaging FFT snapshots (overlapped 50%) over one minute intervals. This will result in an acoustical mapping of physical, biological, and anthropogenic activity in areas that are known to be more or less frequented by humans and humpback whales. More specific details about the GUI and digital signal processing can be found in Seger et al. (2016).

The results obtained in this study will be used as a Before-After Control-Impact (BACI) marine study. The two EAR deployment locations in 2018 will represent the “before / control” portion of the study. Subsequent years of data collection will be used to assess any changes to both anthropogenic and biologic sounds, especially those of humpback whales, as the “after / impact” portion.

For further information contact:

E-mail: silveria66@hotmail.com
Website: www.researchgate.net/project/PHySIC-Ports-Humpbacks-y-Sound-In-Colombia
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