New paper on integrated approaches to studying baleen whales – Ari Friedlaender on BioScience cover!

A new paper was recently published in BioScience, involving a number of SEA partners and BRS collaborators.

Integrative Approaches to the Study of Baleen Whale Diving Behavior, Feeding Performance, and Foraging Ecology

Jeremy A. Goldbogen, Ari S. Friedlaender, John Calambokidis, Megan F. McKenna, Malene Simon and Douglas P. Nowacek

BioScience Vol. 63, No. 2 (February 2013), pp. 90-100

 available at:

Abstract: For many marine organisms, especially large whales that cannot be studied in laboratory settings, our ability to obtain basic behavioral and physiological data is limited, because these organisms occupy offshore habitats and spend a majority of their time underwater. A class of multisensor, suction-cup-attached archival tags has revolutionized the study of large baleen whales, particularly with respect to the predatory strategies used by these gigantic bulk filter feeders to exploit abundant oceanic resources. By integrating these data with those from other disciplines, researchers have uncovered a diverse and extraordinary set of underwater behaviors, ranging from acrobatic diving maneuvers to extreme feeding events during which whales engulf volumes of prey-laden water that are much larger than their own body. This research framework not only improves our knowledge of the individual performance and behavior of these keystone predators but also informs our ability to understand the dynamics of complex marine ecosystems.


SEA’s own Dr. Ari Friedlaender (in action above) appeared on the cover of BioScience as the article was featured in the most recent issue.

Dr. Ari Friedlaender’s Smithsonian Blog on Blue Whale Feeding

We are proud to note that our very own Ari Friedlaender wrote a great blog for the Smithsonian’s Ocean Hall on our recent paper lead by Jeremy Goldbogen on feeding mechanics in blue whales <see:>.

The text is below and you can find it online at <>


I have a vivid childhood memory of sitting under the Blue Whale model hanging in the Natural History Museum, eating an ice cream and wondering how in the world did that whale get so big!  Over the past several years a group of researchers have been asking similar questions about just how do whales get so big and how do they eat.

Using small, state-of-the-art suction-cup tags and new visualization tools we can now understand the underwater movements of these ocean giants and how they are able to feed on dense patches of prey to consume up to 1 ton of food a day!  Blue whales are in a family of whales that have evolved comb-like baleen and large mouths to gulp huge volumes of prey-rich water and then sieve out the small crustaceans or fish that are their main food source.

What we recently found out was that blue whales, the largest animal to have ever lived on planet Earth, sometimes feed by conducting 360° rolls when they open up their cavernous mouths and lunge into an unsuspecting patch of krill.  We found that as the whale approaches the prey patch, it rolls over 180°, on to its back, lunges with mouth agape, and then continues to complete the full roll as it closes its mouth full of prey-laden water.  This maneuver is powered by several powerful fluke strokes and tilting its pectoral flippers to help guide the whale through this energetically costly and acrobatic maneuver.

We think that this behavior improves the whales’ chances of engulfing the most krill as possible in a single gulp.  Krill, small crustaceans like shrimp, have evolved ways to try and escape from predators when they can see them coming, and blue whales are easier to see than anything else in the ocean given their enormous size.  However, if the blue whale feeds from coming up from below the krill where it is dark, they may be able to avoid being detected until the last moment when krill cannot avoid them.  The rolling behavior we observed is likely part of an ambush strategy to feed directly from below the krill.  The rolling half way over before opening the mouth likely helps to maximize the amount of krill the whale can consume at once.

By coming up from below the krill patch, the whale is also taking advantage of counter-shading, and can see the size and shape of the krill patch as it approaches.  The rolling behavior helps the whale because their eyes are on the sides of its head and rolling would allow the whale to see the patch with both eyes and help make its ambush approach as accurate as possible.

While we have not observed such dramatic rolling maneuvers by other baleen whales, we still know very little about how these ocean giants feed and we expect to keep researching these incredible animals to learn new and valuable information on how they live.  One thing is for sure, whales are big because they are really good at what they do!

NOAA Issues Cetacean and Sound Mapping Working Group Report

NOAA recently announced the release of a report from a workshop last summer on new tools for visualizing cetacean density and anthropogenic sound. The report is entitled:

National Oceanic and Atmospheric Administration. 2012. Mapping Cetaceans and Sound: Modern Tools for Ocean Management. Final Symposium Report of a Technical Workshop held May 23-24 in Washington, D.C. 83 pp.

and it is available online at: <>.

Brandon Southall served as a co-chair of the sound field mapping working group in this overall effort.

New Paper on Blue Whale Feeding Behavior



We are proud to announce the publication of a new paper on blue whale feeding behavior that features tagging data collected within the Southern California Behavioral Response Study (SOCAL-BRS) project. The paper is entitled “Underwater acrobatics by the world’s largest predator: 360° rolling manoeuvres by lunge-feeding blue whales“ Dr. Jeremy Goldbogen, a post-doctoral researcher at Cascadia Research, was the lead author paper with a number of other colleagues, including partners from the SOCAL-BRS team.

You can link to the paper at: <> and to the video supplement at:

The full citation of the paper is: Goldbogen JA, Calambokidis J, Friedlaender AS, Francis J, DeRuiter SL, Stimpert AK, Falcone E, Southall BL. 2012. Underwater acrobatics by the world’s largest predator: 360° rolling manoeuvres by lunge-feeding blue whales. Biol Lett 9:20120986. and the abstract of the paper is given below.


ABSTRACT: The extreme body size of blue whales requires a high-energy intake and therefore demands efficient foraging strategies. As an obligate lunge feeder on aggregations of small zooplankton, blue whales engulf a large volume of prey-laden water in a single, rapid gulp. The efficiency of this feeding mechanism is strongly dependent on the amount of prey that can be captured during each lunge, yet food resources tend to be patchily-distributed in both space and time. Here, we measured the three-dimensional kinematics and foraging behaviour of blue whales feeding on krill, using suction-cup attached multi-sensor tags. Our analyses revealed 360° rolling lunge-feeding manoeuvres that reorient the body and position the lower jaws so that a krill patch can be engulfed with the whale’s body inverted. We also recorded these rolling behaviours when whales were in a searching mode in between lunges, suggesting that this behavior also enables the whale to visually process the prey field and maximize foraging efficiency by surveying for the densest prey aggregations. These results reveal the complex manoeuvrability that is required for large rorqual whales to exploit prey patches and highlight the need to fully understand the three-dimensional interactions between predator and prey in the natural environment.


Additionally, please see the following links to some of the media coverage of these new and intriguing findings about foraging behavior in blue whales.’_diet_and_exercise_rolled_into_one


One final note is that many of the above links include photos of blue whales from the SOCAL-BRS project such as the one below. This and all other photos taken during the SOCAL-BRS project were taken under NMFS permit #14534 by different researchers (in this case Ari Friedlaender).

Blown out to end SOCAL-12…

Well our marginal weather conditions ended and Mother Nature rendered the last few days of our SOCAL-BRS project this year ones of just trying to get back safely. We did and while we broke some things fortunately they were just things. We had to duck into Santa Barbara Island and hide in the minuscule wind shadow afforded by that speck of land and then forge north through 30 knot gusts and 6-8 foot seas yesterday (see above) to just get back. We have been blessed on this project with many periods of favorable weather and beautiful seas, but got the other end of the stick this time.

As we come to the end of our field work for this calendar year, I want to say particular thanks to a really amazing crew of dedicated and talented researchers, to all those outside our team from NOAA and other organizations that have helped us succeed, and especially to our program sponsors at the Navy’s Environmental Readiness Program (Living Marine Resources) and the Office of Naval Research. I will post a final summary of our SOCAL-12 accomplishments and status of our data analysis and upcoming publications in the next few days and will provide regular updates as well as they come about. As always, we remain dedicated to an open and transparent process with regard to this program’s goals, actions, and findings, and I encourage anyone to post comments to this blog or to contact me directly at

Below is a parting view of the sunrise over Santa Catalina Island – just one of the very different and beautiful places in the amazing Channel Islands.

Angels of Avalon…

To be honest, today was a bit frustrating for us on SOCAL-BRS. High winds and rough seas early and much of the day searching for an acoustic buoy without finding it meant we used the break forced upon us by Mother Nature to do a final reprovisioning and refueling in the port of Avalon on Santa Catalina Island. We also repositioned for what looks like a last shot at good weather tomorrow and part of Tuesday. If the forecast matches reality, we will hopefully be 50+ miles offshore for the next few day – and consequently without cell or internet contact until mid-week. We will let you know as soon as possible how we are faring out here at sea for the last few days of the second phase of our project – we will be at sea until Thursday.

Misty offshore fin whales

Yesterday, like today, was grey and misty with occassional rain offshore here in SOCAL. With the rain and stronger winds further offshore in the afternoon we again couldn’t get all the way out to the deep-water areas we wanted to. However, we did manage to work out of Catalina to the west and by mid-morning came across a group of fin whales. The photo below (taken under NMFS permit #14534 – photo credit E. Falcone) shows one of these whales with Catalina in the grey background and bumpy seas.

We managed to tag one and followed it for the rest of the day conducting visual observations, mapping potential prey fields along it’s track, and ultimately conducting a controlled sound exposure experiment. The animal continued it’s southward track until the tag came off later in the day and our small boat recovered it before a wet and dark ride back to meet us. Our work out here is certainly exciting and enjoyable and we believe we are addressing important questions, but it’s definitely hard work especially on days like yesterday. We are very fortunate on this project to have so many talented and hard-working people from many different organizations (see: for more details).

SOCAL BRS – Traveling blue whales and breezy seas

We’ve had some less than ideal weather the past few days out at sea for SOCAL-BRS but we have still managed to get some work done. We’ve worked offshore as much as possible but with Santa Ana winds several days ago shifting the prevailing winds around and complicating some of our typical sheltered areas we haven’t been able to work some of the preferred areas. Yesterday we had several acoustic detections of beaked whales in deeper water near Catalina Island and spent much of the day trying to tag Rissos dolphins, but the sea conditions were just a little too rough. We did get two suction cup tags attached to common dolphins, although neither remained attached long enough to conduct a controlled exposure experiment (CEE).

One of the behavioral conditions we are interested in testing responses within for baleen whales are calling animals. We have found several slowly traveling and apparently calling blue whales as we have been working offshore. These animals are typically harder to get tags attached to, especially in the rougher conditions you can see, and we struck out once but did get one caller tagged and a CEE done. Below is a photo of a DTAG attached to a traveling/calling blue whale from two days ago south of Santa Barbara Island (photo taken under NMFS permit #14343 – credit: A. Friedlaender).

We had a variety of listening sensors in the water while this animal was tagged, including the tag itself which collected dozens of calls of several types (see below – courtesy A. Stimpert). This animal was traveling slowly and conducting relatively long but shallow dives consistent with calling behavior. There were several animals calling that we heard, but these clear signals were most likely coming from the tagged animal. Having these clear call records synchronized with fine scale moving behavior in the context of a behavioral response experiment provides us with some important new information about responses to sound in animals with different behavioral contexts.



BEGIN SOCAL-12 PHASE II – An old friend (again) and some new species

For everyone following the SOCAL-BRS from-the-field blog over the past few seasons, welcome back! We just got going on our field project again for the second phase of our field efforts this year and have some new things to report. The weather hasn’t been ideal at the start here although we have had a few workable windows. Additionally, we aim to have a variety of options to work with different priority species given that weather is sometimes difficult offshore, but the very warm and clear surface water off southern California right now is resulting in very few plankton-feeding baleen whales in coastal areas and limiting our options to some degree. But despite these challenges for the first few days we have made some interesting observations and had some successes.

For about the 7th different time in this project over the last three years we had a repeat encounter with our old friend Mango the sperm whale. He is a robust animal who clearly covers large areas in the southern California Bight but returns to a lot of the areas we do. We did not attempt any  subsequent tagging efforts with him but did obtain additional photo ID records. Below is a nice short of his broad tail (Photo taken under NMFS permit #14534 by A. Friedlaender).


We have also had quite a few sightings of coastal and offshore bottlenose dolphins, including this nice shot of a mom-calf (Photo credit: A. Friedlaender), but given our lack of success getting suction cup acoustic tags to stay on this species we have not attempted subsequent tagging or CEEs.


Yesterday we found an interesting mixed-species feeding aggregation of birds, humpback whales, sea lions, and dolphins, each of which (including the humpback whales actually) were focused on large schools of small fish. We focused on the humpback whales, which are important for this project because of their endangered species status and the fact that their responses to these kinds of sounds are almost entirely unknown.

We observed this feeding aggregation (see above- photo credit: A. Friedlaender) for several hours before attaching suction cup acoustic tags to two of the animals and continuing to monitor them and other animals in the area. With three boats monitoring the group in an area sufficiently offshore, we conducted a controlled exposure experiment within our specified safety and experimental criteria. As has happened several times in our project, an interested sea lion came over to check out our sound source during the transmissions and despite it seeming more interested than annoyed or impacted by it, we diligently shut the sound source down as specified in our research permits; the data were still important and useful as this was within just a few minutes of the specified period. One of the tags on the humpbacks remained on the animal a full 24 hours which will provide a wealth of information on any potential responses and behavior later yesterday and today; the animal was relocated fairly nearby and monitored for several hours in normal behavioral modes with the same other humpbacks today until we recovered the tag.

The offshore weather forecast for the next few days off southern California looks quite favorable so we will be heading back offshore tomorrow so do realize that we will be without internet access for this period. We will provide a detailed update on our status and progress as soon as possible. Thanks so much for all the encouragement, interest, support, and feedback through the blog and by emails on our efforts to better understand the basic biology of marine mammals in southern California and their response to sounds. If you missed it on the blog while we were between research phases, please do note that we recently had a paper on our experimental methods published in the Marine Technology Society Journal

<please see:>


SOCAL-BRS paper published in Marine Technology Society Journal

We are pleased to announce the publication of a new paper regarding new technologies and the evolution of experimental methods in the first two years of the Southern California Behavioral Response Study (SOCAL-BRS). The reference, abstract, and where to acquire the article are given below.

Brandon L. Southall, David Moretti, Bruce Abraham, John Calambokidis, Stacy L. DeRuiter, Peter L. Tyack. (2012).    Marine Mammal Behavioral Response Studies in Southern California: Advances in Technology and Experimental Methods.  Marine Technology Society Journal 46(4), 46-59.

ABSTRACT: Behavioral response studies (BRS) are increasingly being conducted to better understand basic behavioral patterns in marine animals and how underwater sounds, including from human sources, can affect them. These studies are being enabled and enhanced by advances in both acoustic sensing and transmission technologies. In the design of a 5-year project in southern California ( SOCAL-BRS), the development of a compact, hand-deployable, ship-powered, 15-element vertical line array sound source enabled a fundamental change in overall project configuration from earlier efforts. The reduced size and power requirements of the sound source, which achieved relatively high output levels and directivity characteristics specified in the experimental design, enabled the use of substantially smaller research vessels. This size reduction favored a decentralization of field effort, with greater emphasis on mobile small boat operations capable of covering large areas to locate and tag marine mammals. These changes in configuration directly contributed to significant increases in tagging focal animals and conducting sound exposure experiments. During field experiments, received sound levels on tagged animals of several different species were within specified target ranges, demonstrating the efficacy of these new solutions to challenging fi eld research problems.

Keywords: marine mammals, noise, underwater sound, transducer, behavioral response study

A .pdf of this article is available for professional use at or by request from Information regarding MTSJ and this issue of the journal is given below:

“The Marine Technology Society is a not-for-profit, international, professional association.  Founded in 1963, the Society believes that the advancement of marine technology and the productive, sustainable use of the oceans depend upon the active exchange of ideas between government, industry and academia. See”

Access the MTS Journal online at 

Techniques, and Strategies for Ocean Exploration

Volume 46, Number 4

Journal Preview

The world’s seafloor for which we have first-hand accounts, detailed maps, and samples remains minuscule, new vehicles, instrumentation, and strategies will be needed to shape our current and future exploration programs. This issue presents a number of papers that illuminate different aspects of ocean exploration.

Table of Contents

Message from the MTSJournal Editor
Ann E. Jochens

Multiplatform Ocean Exploration: Insights From the NEEMO Space Analog Mission
Arthur C. Trembanis, Alex L. Forrest, Douglas C. Miller, Darlene S. S. Lim,
Michael L. Gernhardt, William L. Todd

The Untethered Remotely Operated Vehicle PICASSO-1 and Its Deployment From Chartered Dive Vessels for Deep Sea Surveys Off Okinawa, Japan, and Osprey Reef, Coral Sea, Australia
Dhugal J. Lindsay, Hiroshi Yoshida, Takayuki Uemura, Hiroyuki Yamamoto, Shojiro Ishibashi, Jun Nishikawa, James D. Reimer, Robin J. Beaman, Richard Fitzpatrick, Katsunori Fujikura,Tadashi Maruyama

A New System for Three-Dimensional High-Resolution Geophysical Surveys
Peter Sack, Tor Haugland, Graeme Stock

Implementation of a Seafloor Sediment Corer With a Novel Hydrostatic Motor
Jianjun Wang, Huawei Qin, Ying Chen

Marine Mammal Behavioral Response Studies in Southern California: Advances in Technology and Experimental Methods
Brandon L. Southall, David Moretti, Bruce Abraham, John Calambokidis,
Stacy L. DeRuiter, Peter L. Tyack

Observations of Nepheloid Layers in the Yangtze Estuary, China, Through Phase-Corrupted Acoustic Doppler Current Profiler Speeds
Zhenyi Cao, Xiao Hua Wang, Weibing Guan, Les J. Hamilton, Qi Chen, Dedi Zhu

Investigating the Influence of the Added Mass Effect to Marine Hydrokinetic Horizontal-Axis Turbines Using a General Dynamic Wake Wind Turbine Code
David C. Maniaci, Ye Li


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

Southall Environmental Associates, Inc.

Reducing environmental impacts from essential human activities requires unique approaches to meet challenging conservation objectives in the 21st century. SEA, Inc. works globally with diverse scientific teams and cutting-edge technologies to provide real-world solutions. Learn more about SEA