Photo of the Week: Cetacean Signal


Biological oceanography student Rebecca Cohen tracks a radio signal from a tag placed on a blue whale earlier this week in this photo taken aboard R/V Sproul by staff research associate Jennifer Trickey of Scripps Acoustic Ecology Laboratory.

The research was part of a mix of activities on a cruise organized by assistant researcher Simone Baumann-Pickering to use passive and active acoustics to examine relationships of cetacean and prey densities. Baumann-Pickering's project was funded by the Office of Naval Research's Young Investigator Program.

"Through this project we have identified that sound is produced within the mesopelagic community and we are in the process of describing the long-term variability of these sounds based on fixed sensors," Baumann-Pickering wrote. "In conjunction with this, we investigate the relationship of intensity of acoustic backscatter and ambient sound across time and space. To link this to cetacean presence, we are using passive acoustics and visual observations for predictive modeling of cetacean presence on naval ranges and mitigation of impacts during naval exercises.

"For this cruise we paired up with Ana Širović ( and John Calambokidis (Cascadia Research Collective,, who are funded through the ONR and U.S. Navy Living Marine Resources programs to study behavioral context of blue and fin whale calling and to apply it to density estimation of these species at the Navy ranges. As part of that project we have been deploying acoustic tags on blue and fin whales."

The photo shows the use of a radio signal to track a blue whale tagged with an Acousonde tag by John Calambokidis and James Fahlbusch from Cascadia Research.

"These are archival tags, meaning that the data (acoustics, depth, accelerometer) are stored on the tag and we have to recover it once it falls off the whale to retrieve the data," Sirovic wrote. "We spent the night tracking the whale until the tag finally fell off the following morning and we successfully recovered it full of good-quality data."

More photos from the cruise and other activities of the Scripps Acoustic Ecology Laboratory are available on the lab's Twitter feed.

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