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SC/69B/SH/17
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Resource ID
22159
Access
Open
Document Number
SC/69B/SH/17
Full Title
Trends in cetacean occurrence from long-term passive acoustic monitoring near the South Shetland Islands/ Islas Shetland del Sur
Author
Lauren M. Baggett, Clara Schoenbeck , Simone Baumann-Pickering, John A. Hildebrand, Mariana L. Melc n, Natalie Posdaljian, M. Vanesa Reyes Reyes , Ally Rice, Ana ?irovi?, Alba Solsona-Berga, Jennifer S. Trickey, Miguel A. I iguez Bessega
Authors Summary
A variety of cetacean species inhabit the productive waters near the South Shetland Islands/Islas Shetland del Sur in the western Antarctic Peninsula. Cetacean acoustic activity was monitored at three different sites and three consecutive years. Acoustic time series were generated for a variety of cetacean acoustic signals, including mysticete (blue whale D and Z calls, fin whale 20 Hz calls, and humpback whale calls) and odontocete signals (killer whale clicks, long-finned pilot whale clicks, sperm whale clicks, and a variety of unknown beaked whale (BW) FM pulse types (BW29, BW37, and BW58)). Acoustic recorder deployments covered between 131 and 353 days of effort per year, fin whales, blue whales, humpback whales, long-finned pilot whales, sperm whales, BW29, and BW37 seemed to be visiting the sites seasonally with spatial preferences and variability. The time series were compared to sea ice data from the respective period and site, to make observations between sea ice coverage and cetacean presence. When no sea ice was present, there tended to be higher acoustic signal densities of sperm whales, pilot whales, BW29, and BW37. When sea ice coverage began to decrease, humpback whale occurrence appeared to increase. These trends could be further explored by using statistical models to quantify the relationships between environmental covariates and cetacean acoustic presence. Understanding seasonal and spatial trends in cetacean occurrence in this region is key for conservation of these populations, some of which have historically been decimated by whaling and all of which may be vulnerable to impacts from anthropogenic climate change.
Publisher
IWC
Publication Year
2024
Abstract
A variety of cetacean species inhabit the productive waters near the South Shetland Islands/Islas Shetland del Sur in the western Antarctic Peninsula. Cetacean acoustic activity was monitored at three different sites and three consecutive years. Acoustic time series were generated for a variety of cetacean acoustic signals, including mysticete (blue whale D and Z calls, fin whale 20 Hz calls, and humpback whale calls) and odontocete signals (killer whale clicks, long-finned pilot whale clicks, sperm whale clicks, and a variety of unknown beaked whale (BW) FM pulse types (BW29, BW37, and BW58)). Acoustic recorder deployments covered between 131 and 353 days of effort per year, fin whales, blue whales, humpback whales, long-finned pilot whales, sperm whales, BW29, and BW37 seemed to be visiting the sites seasonally with spatial preferences and variability. The time series were compared to sea ice data from the respective period and site, to make observations between sea ice coverage and cetacean presence. When no sea ice was present, there tended to be higher acoustic signal densities of sperm whales, pilot whales, BW29, and BW37. When sea ice coverage began to decrease, humpback whale occurrence appeared to increase. These trends could be further explored by using statistical models to quantify the relationships between environmental covariates and cetacean acoustic presence. Understanding seasonal and spatial trends in cetacean occurrence in this region is key for conservation of these populations, some of which have historically been decimated by whaling and all of which may be vulnerable to impacts from anthropogenic climate change.