SEA Presentations at 21st Biennial Conference on the Biology of Marine Mammals

Researchers from Southall Environmental Associates were involved in many presentations of cutting-edge marine mammal science at the recent 21st Biennial Conference on the Biology of Marine Mammals in San Francisco. It was an outstanding meeting, culminating with a reception at City Hall (see below) to commemorate the return of the biennial meetings to the city in which the first meeting was held 42 years ago.





Here are some of the abstracts involving SEA Senior Scientist Dr. Brandon Southall:

Southall, B., DeRuiter, S., Friedlaender, A., Hazen, E.L., Goldbogen, J.A., Stimpert, A.K., Langrock, R., Harris, C.M., Thomas, L., Schorr, G., Allen, A., Gailey, G., Falcone, E., Moretti, D., and Calambokidis, J. (2015). Complementary analyses of behavioral responses to sonar in blue whales (Balaenoptera musculus).

Benoit-Bird, K., Arranz, P, Tyack, P.L. Moline, M, and Southall, B. (2015). Predator-prey dynamics in the mesopelagic: Odontocete foraging ecology and antipredatory behavior of prey.

Nowacek, D.P., Clark, C.W., Donovan, G., Gailey, G., Golden, J., Jasny, M., Mann, D.A., Miller, P.J., Racca, R., Reeves, R.R., Rosenbaum, H., Southall, B., Vedenev, A., and Weller, D.W. (2015). Marine seismic surveys and ocean noise: mitigation, monitoring and a plan for international management.

Stimpert, A.K., DeRuiter, S., Falcone, E., Joseph, J., Douglas, A.B., Moretti, D., Friedlaender, A., Calambokidis, J., Gailey, G., Tyack, P.L., Southall, B., and Goldbogen, J.A. (2015). Tagged fin whale call production, associated behavior, and response to anthropogenic sound in the Southern California Bight.

DeRuiter, S., Isojunno, S., Noirot, Stimpert, A.K., Zimmer, W., Leung, M.R., Harris, C.M., Thomas, L., Southall, B., Tyack, P.L., and Miller, P.J. (2015). Sperm whale foraging behavior in response to anthropogenic sound.

Ellison, W.T., Clark, C.W., Mann, D.A., Southall, B., and Tollit, D.J. (2015). A risk assessment framework to assess the biological significance of noise exposure on marine mammals.

Fregosi, S., Klinck, H., Horning, Markus, Mellinger, D.K., Costa, D.P., Mann, D.A., Sexton, K., Huckstadt, L.A., and Southall, B. (2015). Turn down for what: Animal-borne controlled exposures as an innovative tool for dive manipulation in free-ranging marine mammals.

Heenehan, H.L., Bejder, L, Tyne, J.A., Southall, B., Southall, H., and Johnston, D.J. (2015). Using soundscape metrics to describe changes to ambient noise levels in the resting bays of Hawaiian spinner dolphins (Stenella longirostris).

Allen, A., Goldbogen, J.A., Friedlaender, A., Calambokidis, and Southall, B. (2015). An automated lunge detector for baleen whale tag data: application and results for fin whales off Southern California.

Bowers, M., DeRuiter, S.L., Friedlaender, A.S., Nowacek, D.P., Quick, N.J., Southall, B., Read, A.J. (2015). Short-finned pilot whales and Risso’s dolphins respond strongly and divergently to biphonic calls of mammal-eating killer whales.

Harris, C.M., Isojunno, S., Thomas, L., A.S., Southall, B., Miller, P.J., Read, A.J., and Tyack, P.L. (2015). Behavioral responses of cetaceans to anthropogenic sound: A community persective on research priorities and future steps.

Jason, J., Blackwell, S.B., Heide-Jorgense, M.P., Southall, B., Friedlaender, A., Thometz, N.M., and Williams, T.M. (2015). Measuring instantaneous energetic costs in highly maneuverable marine mammals.

Brandon Southall Publishes “Science at Sea” Featured Column (Times Publishing)

SEA President and Senior Scientist was recently invited to publish a featured column in the Science at Sea series in the Aptos, Capitola/Soquel, and Scotts Valley Times newspapers. His piece is available in the current version of these publications and is available online:

026_Sunrise over Catalina_B Southall

The text of the first several paragraphs of the article are given here – reprints are available on request.

Views can be spectacular looking out on the ocean, but our Monterey Bay marine layer often obscures your gaze. And when you dip below the waves and peer into the sea, other than those rare moments of wavering clarity, the darkness is enveloping. But listen to the living underwater soundscape and a whole new world emerges.

From the rhythmic ocean metronome of waves to the clicks and moans of animals and from the rumble of underwater earthquakes to the crack of lightning striking the surface, nature fills the sea with sound. Unlike our early perceptions, there is little silence in the ocean.

Animals have made sound under water for millions of years. They use social calls to track their young and compete with one another. Some even use songs to attract mates. Many species use sound as a general means of orientation – knowing where they are going and if predators are around. Some specialized animals, the dolphins and porpoises, have specialized biosonar sounds like bats to focus in on individual prey while they are feeding.

Sound is so critical to many marine animals, particularly those with backbones, in part because light is so limited in the ocean. While many species can see quite well and some smell or feel things close to them, the physics of water means that making and listening to sounds is simply the best way to accomplish these key life functions.

(please see the above link for more…)



Tagged blue whale in SOCAL-BRS project (Taken under NMFS permit #14534, J. Calambokidis)

We wanted to pass along a recent manuscript on optimal foraging in blue whales as a function of oxygen use and prey density.

Hazen, E., Friedlaender, A., & Goldbogen, J. A. 2015. Blue whales change their foraging strategies relative to prey density. Scientific Advances, e1500469

The abstract is below and the full text is open access and available at:


Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold. It is thought that diving predators optimize their foraging success when oxygen use and energy gain act as competing currencies, but this hypothesis has not been rigorously tested because it has been difficult to measure the quality of prey that is targetedby free-ranging animals. We used high-resolution multisensor digital tags attached to foraging blue whales (Balaenoptera musculus) with concurrent acoustic prey measurements to quantify foraging performance across depth and prey density gradients. We parameterized two competing physiological models to estimate energy gain and expenditure based on foraging decisions. Our analyses show that at low prey densities, blue whale feeding rates and energy intake were low to minimize oxygen use, but at higher prey densities feeding frequency increased to maximize energy intake. Contrary to previous paradigms, we demonstrate that blue whales are not indiscriminate grazers but instead switch foraging strategies in response to variation in prey density and depth to maximize energetic efficiency.


Please also see a subset of media resulting from this article (click to link to each)

End SOCAL-15 Phase II

Well we have come to the end of our field effort for the SOCAL-BRS summer 2015 effort. We have had some good accomplishments, including tagging 9 animals of three of our four focal species (fin and blue whales plus Risso’s dolphin – we did not manage to tag a beaked whale this time). We were also able to conduct five full experimental sequences among these tagged animals (including the blue whale pictured below; J. Calambokidis taken under NMFS permit #14534), including one coordinated with a real Navy ship in the course of it’s normal training operation.

Tagged Blue Whale_J Calambokidis

However, this has been among the more challenging periods of effort on this project for a number of reasons. Among them was the predominately offshore and thin distribution of whales off southern California. The very warm waters have brought in a lot of more typically southern species, including lots of tuna, mahi mahi, and hammerhead sharks, but they have also pushed the whales more offshore and to areas further to the north through effects on their prey distribution. Our being offshore so much during this period limited the blog updates and also meant we worked less in some of our more familiar and typical areas such as around Long Beach and Palos Verdes. Lastly, we unfortunately had two of our recording tags fail and were not (yet!) recovered. Last year we lost one and someone kayaking in LaJolla found it. So if you are out down there and see something shiny and gold/black with an antenna popping out of it, make sure to grab it and give us a call!

Two tagged fins_Friedlaender

Many people are required to complete the kind of complex, dispersed, and physically challenging efforts that these projects are. I want to personally thank all of our field team for their dedicated effort. I would also like to thank the crew of the Truth from Truth Aquatics, notably Davey Woodland. We also very much appreciate the continued help, support, and encouragement from Diane Alps and our friends at the Cabrillo Marine Aquiarium. We will be back on the water in a smaller shore-based contingent in about a month and I will pick the blog back up then. We expect to have at least one new paper coming out between now and then so stay tuned. You can find more resources and information on the project through the webpage <> and look for the drop down menus for each year. Or email me personally at with questions, comments, or to get any reprints of our papers not already available on the site.



Warm Waters and Offshore Whales

SOCAL-BRS is progressing well in some ways, despite the extremely limited distribution of large baleen whales in some of our typical coastal areas. As you may have read, the strong El Nino conditions that are setting up off California have resulted in some very warm water temperatures. As a result, we are seeing a lot more large whales spread out and much further offshore in deeper water and typically in some deeper diving modes where they can be a little harder to approach and tag. We have been in some of the offshore waters and have had some success in tagging and conducting three experimental sequences so far in the first five days of this field phase. We have tagged several fin whales and blue whales (including the one below) and a single Risso’s dolphin (though just briefly on the later).




Tagged Blue Whale_J Calambokidis

DTAG on a blue whale off southern California (J. Calambokidis, permit #14534)


We have been searching all day and night for one wayward tag with some important data on it (if you are off Oceanside fishing and you see something gold floating in the water…). We have also included some longer term TDR kinds of sensors that let us track animals for longer periods but with less resolution and we are using these in concert with the high resolution shorter term tags. The weather forecast for some of the further offshore areas doesn’t look great for the next few days but we will get back out there and hope to have some workable periods. We will report some additional results and post some additional photos in the next few days

Good start with fin whales

SOCAL-BRS is now operational for our second field phase of 2015. We are working with several research vessels including the Truth out of Santa Barbara and have been searching the coastal and offshore waters for our focal species. These include endangered blue and fin whales as well as beaked whales and Risso’s dolphins. Again, you can find much more information about our objectives and methods in the SOCAL-15 Public Summary linked from the SOCAL-15 page in the drop down menu on the SOCAL-BRS main page.This blog will serve to provide short updates of our field progress.

The first few days have seen a few good things, but honestly a fair amount of area covered without a lot of focal animals. The very warm surface ocean temperatures you may have been reading about almost certainly has a lot to do with that and we are simply not seeing many large whales feeding in areas where we commonly see them. This is proving a little challenging, but the approach on this project has always been to have contingency areas and focal species. Accordingly, we have moved to some slightly more offshore areas. Yesterday we tagged a Risso’s dolphin but the tag was off quickly and today we had some good success in managing to tag an adult fin whale with an acoustic and movement recording tag (see below – credit: J. Calambokidis taken under NMFS permit # 14534).

DTAG fin whale_Calambokidis

We hope to move a little further offshore tomorrow to search some new areas with relatively good weather. If we stay out there our communications are quite limited, but we will update the blog with more information. In the meantime, please do check out the rest of the site for some of our work, including the many recent papers announced and linked from the site resulting from our experimental research on this project.

SOCAL-BRS in the Field – Follow us!

On behalf of all the collaborators and partnering organizations that are a part of the amazing field research effort known as the Southern California Behavioral Response Study (SOCAL-BRS), I would like to make folks who follow our blog aware that we have just started another phase of field work in this continuing project.

You can find more information specifically on this year’s plans and objectives at <> and specifically <>. There is a .pdf public summary describing the work there and many of the dozen peer-reviewed scientific publications from this prolific project are available there. I serve as the Chief Scientist of this project and am willing and completely available to address any questions or comments or requests for reprints or informations <>

We have made an very specific point to be very transparent and open in our interactions and information about this project. The above referenced summary is an example, as is our from-the-field blog which will appear here and will give semi-regular updates on our progress. There will be postings every several days at this site to provide that information, including photos to show focal species and tagged animals. Today was our first day on the water and while the distribution of baleen whales looks to be quite thin right now – owing almost certainly to the quite warm water – we did have visual detections and tag attempts on blue and fin whales and Risso’s dolphins today (but had just one very short attachment).
Thanks for your interest in our work and for following the from the field blog. Please do provide appropriate feedback and comments here or by email.


New SOCAL-BRS publication on fin whale vocalizations



The SOCAL-BRS team is proud to announce the publication of an important new paper on the calling behavior of endangered fin whales (like the one below, tagged with one of the sensors described in the paper – credit J. Calambokidis under NMFS permit #14534).

DTAG fin whale copy

Dr. Alison Stimpert of Moss Landing Marine Laboratory led the study, which provides key baseline information on the calling and kinematic movement behavior of these amazing animals. The reference for this paper and the DOI number is given below – you can freely obtain this paper through Open Access.


Stimpert et al. Animal Biotelemetry (2015) 3:23

DOI 10.1186/s40317-015-0058-3

Sound production and associated behavior of tagged fin whales (Balaenoptera physalus) in the Southern California Bight

Alison K Stimpert1*, Stacy L DeRuiter2,3, Erin A Falcone4, John Joseph5, Annie B Douglas4, David J Moretti6, Ari S Friedlaender7,8, John Calambokidis4, Glenn Gailey4, Peter L Tyack9 and Jeremy A Goldbogen10


1 Vertebrate Ecology Laboratory, Moss Landing Marine Laboratories, Moss Landing, CA, USA.

2 Centre for Research into Ecological and Environmental Modelling, School of Mathematics and Statistics, University of St Andrews, The Observatory, Buchanan Gardens, St Andrews, Fife KY16 9LZ, Scotland, UK.

3 Mathematics and Statistics Department, Calvin College, 3201 Burton SE, Grand Rapids, MI 49546, USA.

4 Cascadia Research Collective, 218 1/2 W.Fourth Ave., Olympia, WA 98501, USA.

5 Ocean Acoustics Laboratory, Department of Oceanography, Naval Postgraduate School, Monterey, CA, USA.

6 Naval Undersea Warfare Center, Newport, RI, USA.

7 Department of Fisheries and Wildlife, Marine Mammal Institute, Hatfield Marine Science Center, Oregon State University, Newport, OR 97365, USA.

8 Southall Environmental Associates, Aptos, CA 95003, USA.

9 Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, St Andrews KY16 8LB, Scotland, UK.

10 Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Blvd., Pacific Grove, CA 93950, USA.


The new SOCAL-15 page on is now available at: <>. On this page you will find a public summary of our research plans for 2015 <>.

We expect to have our primary research efforts in August and October-November this year and we will provide a blog announcement of the beginning of the from-the-field blog posts that a number of people have enjoyed following as we report our progress in (near) real time from the field.



Blue whale tagged off Palos Verdes (J. Calambokisis, NMFS permit #14534)



On behalf of the research team collaborating on the SOCAL-BRS project to study the behavior of marine mammals in southern California and their responses to human sounds including military sonar, I am pleased to report the completion of our 2014 annual research report. This includes some work that ran later in the season this year and we recently completed the report and are glad to make it publicly available.

The report is available at <>


Risso’s dolphins in social interactions off California (Credit: B. Southall; NMFS permit #14534)

Within this report we provide details on our activities and accomplishments in 2014. We also reference the increasing number of scientific publications the project has and continues to generate. A number of these papers are referenced in the report and available in our resources page here and linked from the main SOCAL-BRS page available at <>. Any of these are also available by email at


Southall, B. L., J. Calambokidis, P. Tyack, D. Moretti, J, Hildebrand, C. Kyburg, R. Carlson, A. Friedlaender, E. Falcone, G. Schorr, A. Douglas, S. DeRuiter, J. Goldbogen, J. Barlow. (2011). Project report: Biological and Behavioral Response Studies of Marine Mammals in Southern California, 2010 (SOCAL-10).

Southall, B. L., J. Calambokidis, P. Tyack, D. Moretti, J, Hildebrand, C. Kyburg, R. Carlson, A. Friedlaender, E. Falcone, G. Schorr, A. Douglas, S. DeRuiter, J. Goldbogen, J. Barlow. (2012). Project report: Biological and Behavioral Response Studies of Marine Mammals in Southern California, 2011 (SOCAL-11).

Southall, B. L., D. Moretti, B. Abraham, J. Calambokidis, P.L. Tyack. (2012). Marine Mammal Behavioral Response Studies in Southern California: Advances in Technology and Experimental Methods. Marine Technology Society Journal 46, 46-59.

Goldbogen J.A., Calambokidis J., Friedlaender A.S., Francis J., DeRuiter S.L., Stimpert A.K., Falcone E., Southall B.L. (2012). Underwater acrobatics by the world’s largest predator: 360° rolling manoeuvres by lunge-feeding blue whales. Biology Letters 9:20120986.

Southall, B. L., J. Calambokidis, P. Tyack, D. Moretti, J, Hildebrand, C. Kyburg, R. Carlson, A. Friedlaender, E. Falcone, G. Schorr, K. Southall, A. Douglas, S. DeRuiter, J. Goldbogen, J. Barlow. (2013). Project report: Biological and Behavioral Response Studies of Marine Mammals in Southern California, 2012 (SOCAL-12).

DeRuiter S.L., Southall B.L., Calambokidis J., Zimmer W.M.X., Sadykova D., Falcone E.A., Friedlaender A.S., Joseph J.E., Moretti, D., Schorr G.S., Thomas L., Tyack P.L. (2013). First direct measurements of behavioural responses by Cuvier’s beaked whales to mid-frequency active sonar. Biology Letters 9: 20130223.

Goldbogen J.A., Southall B.L., DeRuiter S.L., Calambokidis J., Friedlaender A.S., Hazen E.L., Falcone E.A., Schorr G.S., Douglass A., Moretti D.J., Kyburg C., McKenna M.F., Tyack P.L. (2013). Blue whales respond to simulated mid-frequency military sonar. Proceedings of the Royal Society B: 20130657.

Yack, T.M., J. Barlow, J. Calambokidis, B. Southall, S. Coates. (2013). Identification of previously unknown beaked whale habitat in the Southern California Bight using a towed hydrophone array. J. Acoust. Soc. Amer. 134, 2589-2597.

Southall, B. L., J. Calambokidis, P. Tyack, D. Moretti, A. Friedlaender, E. Falcone, G. Schorr, K. Southall, A. Douglas, S. DeRuiter, J. Goldbogen, J. Barlow. (2014). Project report: Biological and Behavioral Response Studies of Marine Mammals in Southern California, 2013 (SOCAL-13).

Friedlaender A.S., Goldbogen, J..A. Hazen E.L., Calambokidis, J.A., Southall, B.L. (2014). Feeding performance of sympatric blue and fin whales exploiting a common prey resource. Marine Mammal Science. DOI: 10.1111/mms.12134.

Goldbogen, J. A., A. K. Stimpert, S. L. DeRuiter, J. Calambokdis, A. S. Friedlaender, G. S. Schorr, D. J. Moretti, P. L. Tyack, B. L. Southall. (2014). Using accelerometers to determine the calling behavior of tagged baleen whales. The Journal of Experimental Biology, jeb-103259.

Stimpert, A. K., DeRuiter, S. L., Southall, B. L., Moretti, D. J., Falcone, E. A., Goldbogen, J. A., Friedlaender, A., Schorr, G.S., & Calambokidis, J. (2014). Acoustic and foraging behavior of a Baird’s beaked whale, Berardius bairdii, exposed to simulated sonar. Scientific Reports, 4: 7031. DOI: 10.1038/srep07031.

Goldbogen, J. A., Hazen, E. L., Friedlaender, A. S., Calambokidis, J., DeRuiter, S. L., Stimpert, A. K., & Southall, B. L. (2014). Prey density and distribution drive the three‐dimensional foraging strategies of the largest filter feeder. Functional Ecology. DOI: 10.1111/1365-2435.12395.


SOCAL-BRS is a study of basic behavior and responses to controlled sound exposures in a variety of marine mammal species.

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