Dear MARMAM community,

On behalf of my coauthors, I am pleased to share our recent publication in Royal Society Open Science:

Barlow DR, Estrada Jorge M, Klinck H, Torres LG. 2022. Shaken, not stirred: blue whales show no acoustic response to earthquake events. Royal Society Open Science. 9:220242. https://doi.org/10.1098/rsos.220242

Abstract: Quantifying how animals respond to disturbance events bears relevance for understanding consequences to population health. We investigate whether blue whales respond acoustically to naturally occurring episodic noise by examining calling before and after earthquakes (27 040 calls, 32 earthquakes; 27 January–29 June 2016). Two vocalization types were evaluated: New Zealand blue whale song and downswept vocalizations ('D calls'). Blue whales did not alter the number of D calls, D call received level or song intensity following earthquakes (paired t-tests, p > 0.7 for all). Linear models accounting for earthquake strength and proximity revealed significant relationships between change in calling activity surrounding earthquakes and prior calling activity (D calls: R² = 0.277, p < 0.0001; song: R² = 0.080, p = 0.028); however, these same relationships were true for ‘null’ periods without earthquakes (D calls: R² = 0.262, p < 0.0001; song: R² = 0.149, p = 0.0002), indicating that the pattern is driven by blue whale calling context regardless of earthquake presence. Our findings that blue whales do not respond to episodic natural noise provide context for interpreting documented acoustic responses to anthropogenic noise sources, including shipping traffic and petroleum development, indicating that they potentially evolved tolerance for natural noise sources but not novel noise from anthropogenic origins.

The full article is open access, and available online: https://royalsocietypublishing.org/doi/10.1098/rsos.220242

Cheers,

Dawn

Dawn Barlow, PhD (she/her)

Marine Mammal Institute | Department of Fisheries, Wildlife, and Conservation Sciences

Oregon State University | Hatfield Marine Science Center

Geospatial Ecology of Marine Megafauna Lab

dawn.barlow@oregonstate.edu