On behalf of lead author John Durban and our co-authors, we would like to bring to your attention the recent publication on the novel integration of several different kinds of research approaches to quantify the behavior and behavioral responses to controlled exposure experiments (CEEs) for several species of common, social delphinid cetaceans. Baseline and potential disturbed behavior has proven challenging to study in these species using conventional methods. Several new advances and insights are presented herein, with results from several dozen CEEs with two species of common dolphins recently collected to follow. The paper is available via open access at <https://www.sciencedirect.com/science/article/pii/S0025326X21012285?via%3Dihub>. The citation and abstract are provided below.

Citation: Durban, J.W., Southall, B.L., Calambokidis, J., Casey, C., Fearnbach, H., Joyce, T.W., Fahlbusch, J., Oudejans, M.G., Fregosi, S., Friedlaender, A.S., Kellar, N.M., Visser, F. (2021). Integrating remote sensing methods during controlled exposure experiments to quantify group responses of dolphins to navy sonar. Marine Pollution Bulletin. https://doi.org/10.1016/j.marpolbul.2021.113194

Abstract: Human noise can be harmful to sound-centric marine mammals. Significant research has focused on characterizing behavioral responses of protected cetacean species to navy mid-frequency active sonar (MFAS). Controlled exposure experiments (CEE) using animal-borne tags have proved valuable, but smaller dolphins are not amenable to tagging and groups of interacting individuals are more relevant behavioral units for these social species. To fill key data gaps on group responses of social delphinids that are exposed to navy MFAS in large numbers, we describe novel approaches for the coordinated collection and integrated analysis of multiple remotely-sensed datasets during CEEs. This involves real-time coordination of a sonar source, shore-based group tracking, aerial photogrammetry to measure fine-scale movements and passive acoustics to quantify vocal activity. Using an example CEE involving long-beaked common dolphins (Delphinus delphis bairdii), we demonstrate how resultant quantitative metrics can be used to estimate behavioral changes and noise exposure-response relationships.

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Brandon Southall, Ph.D

President, Senior Scientist - Southall Environmental Associates, Inc.

Research Associate - UC Santa Cruz Institute of Marine Science

Adjunct Assistant Professor - Nicholas School of the Environment, Duke University

Senior Scientist, California Ocean Alliance

Brandon.Southall@sea-inc.net

831.661.5177 (office)

831.332.8744 (cell)

9099 Soquel Dr., suite 8

Aptos CA 95003 USA

www.sea-inc.net

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