New Marine Mammal Research Project – Integrating Visual and Acoustic Sensors to Study Behavior and Behavioral Response in Small Cetaceans

SEA is proud to partner with Cascadia Research Collective, NOAA/NMFS Southwest Fisheries Science Center, and Kelp Marine Research on a new marine mammal research project beginning off southern California.

                                             “Integrating remote sensing methods to measure social delphinid

baseline behavior and responses to Navy sonar”

This new research collaboration is being supported by the Office of Naval Research Marine Mammals and Biology Program. It builds on several recent and ongoing research efforts to provide high-resolution measurements of behavior and behavioral response of marine mammals to human noise in their environment using controlled exposure experiments. All research is authorized under NMFS permits #16111, 19091, and 19116 as well as numerous Institutional Animal Care and Use Committee and other federal, state, and local authorizations. All research is conducted with explicit monitoring and mitigation requirements in order to ensure studies are conducted safely and ethically while providing vitally needed information on understanding and managing the effects of noise on marine mammals. An initial evaluation of monitoring methods for this project will occur over the next several weeks with experimental work occurring in the fall and next summer. We will provide updates both here and through our research partners. Below is a simple summary of the project and more information is available on request from the project chief scientist at


Oceanic delphinids are generally not endangered or threatened, have typically not been observed in mass-stranding events associated with Navy sonar. Potential responses of these species are often inferred from laboratory measurements or from anecdotal observations in uncontrolled contexts, each of which has significant limitations in predicting responses in these common species for realistic sonar exposures. To date there have been no direct experimental studies of the potential responses of these animals in known, controlled conditions.

Building on related studies in a number of field sites, we will develop and utilize a novel integration of several established remote-sensing methods to quantify behavior and biopsy sampling to measure stress hormone levels in three delphinid species that are common and frequently exposed to Navy mid-frequency active sonar (MFAS) off California. We will evaluate potential responses to simulated mid-frequency active sonar (MFAS) using controlled exposure experiments (CEEs). The nature of the resulting data will be necessarily and categorically different from previous response studies involving tagging of single individuals. Beyond the fact that getting tags to stay on individuals has proven infeasible to date, these social species typically occur in groups and group members likely interact in their response to external stimuli. As such, the group, or part of the group, is likely the more relevant unit of analysis.


I.Develop integrated, cross-disciplinary methods to simultaneously track group movement and behavior using shore- or vessel-based visual observers, aerial photogrammetry, and remote-deployed acoustic recorders.

II.Apply group-sampling methods using integrated technologies to better characterize typical (undisturbed) behavioral parameters for these species.

III.Obtain biopsy samples for use in a collaborative research project to measure stress hormone levels

IV.Obtain direct measurements of group behavioral changes and stress hormone responses, if any, resulting from experimentally controlled simulated Navy MFAS for three delphinid species that occur in large numbers in Navy range areas, including common dolphins (Delphinus sp.), bottlenose dolphins (Tursiops truncatus), and Risso’s dolphin (Grampus griseus).


Building on our recent and ongoing research, we will develop and utilize a novel integration of three different complementary systems to measure aspects of baseline behavior and potential behavioral responses to simulated mid-frequency active sonar (MFAS) using controlled exposure experiments (CEEs) in three delphinid species. Standard biopsy sampling procedures will be used to obtain tissue samples. A custom vertical line array sound source will project simulated MFAS signals at much lower power than real military sonar systems during CEEs. These studies are intended to identify the nature of behavioral responses to potential disturbance from sonar signals and the onset of responses using carefully controlled methods, in order to inform our evaluation of potential responses to more realistic and louder exposures that may occur off California during regular authorized sonar training events.

Remote sensing methods include:

(1) Shore- and vessel-based visual sampling;

(2) Unmanned aerial systems (UAS) for photogrammetry;

(3) Remote-deployed passive acoustic sensors

Brandon Southall Leads Ocean Acoustics Panel at Capital Hill Oceans Weeks

This week is Capital Hill Oceans Week in Washington D.C. Organized by the National Marine Sanctuaries Program, this event brings together ocean policy makers and scientists from around the U.S. to discuss cutting edge issues in marine science and conservation. (please see:

The session is entitled “Cacophony: The decline of silent seas” and it take place on Wednesday, June 14, 2017 from 9:30 am to 10:30 am at the Ronald Reagan Building and International Trade Center (1300 Pennsylvania Ave NW, Washington, DC). The session will be led by SEA’s Dr Brandon Southall. Panelists include experts in marine noise reduction, commercial shipping operations, oil and gas exploration, and marine conservation. A summary of the session is given below.

NOTE: A full video of this panel discussion is now available online


“Diving under the waves often elicits images of a quiet and serene place, but the sea is no longer silent. As use of technology for everything from shipping to energy exploration and production, to military activity increases, our use of the ocean brings with it noise that travels long distances and has lasting effects throughout the marine environment. Numerous marine animals from invertebrates to mammals rely on sound for survival. We are just beginning to understand the full range of how sound is used by these animals – finding prey, mating, avoiding predators, navigating, and communicating – and how anthropogenic noise impacts these functions. This session will explore the current information that exists on ocean noise and its mitigation, with a focus on the development and implementation of noise reduction technology within industry.”


Public Outreach on Marine Acoustics in Monterey Bay

Dr. Brandon Southall will appear with colleagues from MBARI and the Monterey Bay National Marine Sanctuary this Friday March 3rd at 5pm for a First Friday public event entitled:

“Sounds in the Sanctuary: An Opportunity to Listen Beneath the Waves”

Recordings of sounds from animals and people recorded on a new passive acoustics listening system in Monterey Bay will be displayed and explained with an interactive exhibit.

Dr. Brandon Southall serves on United Nations ocean acoustics panel

An international group of ocean scientists and leaders from a range of international research and environmental organizations, government agencies, and industry partners (pictured below) participated in a special session on ship noise and ship strike issues related to marine conservation at a recent preparatory meeting for the United Nations Oceans Conference. SEA’s Brandon Southall was among the invited panelists, which also included the President of the General Assembly of the United Nations.

A summary of the concept note developed for this meeting and a summary of the event is available at the Oceans Conference website: and

Edited video and all the various documents available (including our final WG summary is also available at:


This event lead to the formation of a working group in preparation for the June UN Oceans Conference which has developed a set of voluntary commitments on the reduction of noise in the oceans, for which SEA is proud to be a participating member:

SEA Senior Scientist co-authors IUCN Best Practices Publication on Seismic Surveys

SEA Senior Scientist Dr. Brandon Southall and Dr. Doug Nowacek from Duke co-authored a new publication regarding responsible environmental practices for monitoring and mitigation of seismic airgun surveys. The document is entitled  “Effective planning strategies for managing environmental risk associated with geophysical and other imaging surveys.” It was launched at the World Conservation Congress last night in Honolulu. The PDF of the report is attached. It is also available on the IUCN’s Library Portal online:

Brandon Southall to give DOSITS webinar – Wed 16 March




Members of the international regulatory community have an expressed need for training materials on underwater acoustics as well as instructional resources that can be quickly accessed and viewed. To meet this need, the Discovery of Sound in the Sea (DOSITS) Team is facilitating a free, five-part webinar series on topics related to underwater sound.

Two webinars took place in 2015.  The first reviewed science of sound concepts, the second, sound production and reception in marine animals.  These webinars, PDF versions of the webinar presentations, and other associated resources, have been archived to the DOSITS website (

The third webinar will take place on Wednesday, March 16, 2016, at 12:00 pm (U.S. East Coast time).  Dr.’s Dorian Houser and Brandon Southall will review the potential effects of underwater sound on marine mammals.

Interested individuals must register in advance for this webinar.  To register please visit:

To learn more about this webinar series and view other, upcoming webinar dates and speakers, please visit the DOSITS webpage, Webinar Series for Regulators of Underwater Sound.

Questions?  Please contact Holly Morin at


New publication on Heterogenous Prey Distribution and Beaked Whales


Along with my co-authors Kelly Benoit-Bird and Mark Moline, I would like to bring to your attention a paper recently published in Proceedings of the Royal Society of London B (Biological Sciences) entitled Predator-guided sampling reveals biotic structure in the bathypelagic. The full reference, online location, and full abstract are provided below. We are happy to provide .pdf copies of the article on request by email ( or as a professional courtesy.

Brandon Southall


Benoit-Bird KJ, Southall BL, Moline MA. 2016. Predator-guided sampling reveals biotic structure in the bathypelagic. Proc. R. Soc. B 283: 20152457.

We targeted a habitat used differentially by deep-diving, air-breathing predators to empirically sample their prey’s distributions off southern California. Fine-scale measurements of the spatial variability of potential prey animals from the surface to 1200 m were obtained using conventional fisheries echosounders aboard a surface ship and uniquely integrated into a deep-diving autonomous vehicle. Significant spatial variability in the size, composition, total biomass, and spatial organization of biota was evident over all spatial scales examined and was consistent with the general distribution patterns of foraging Cuvier’s beaked whales (Ziphius cavirostris) observed in separate studies. Striking differences found in prey characteristics between regions at depth, however, did not reflect differences observed in surface layers. These differences in deep pelagic structure horizontally and relative to surface structure, absent clear physical differences, change our long-held views of this habitat as uniform. The revelation that animals deep in the water column are so spatially heterogeneous at scales from 10 m to 50 km critically affects our understanding of the processes driving predator–prey interactions, energy transfer, biogeochemical cycling, and other ecological processes in the deep sea, and the connections between the productive surface mixed layer and the deep-water column.


Marine Mammals and Noise in the Arctic


A recent media piece on noise in the Arctic was published online in Arctic Deeply. SEA Senior Scientist and close colleague Chris Clark of Cornell were among those featured in the article about the science and traditional knowledge of sound and mammal behavior in the Arctic. The link is below as well as several excerpt from the piece.

SE Alaskan horizon

Marine Mammals Unsettled as Arctic Noise Grows

February 19th, 2016 by Cheryl Katz

Industrial noise from ships, offshore development and military activity is exposing Arctic marine mammals to unprecedented amounts of man-made racket. With the retreat of the sea ice, scientists figure the Arctic Ocean will only get louder. Can they muffle the din?

Noise from industrial activities can disturb sea life throughout the world’s oceans, but the problem may be especially acute in the Arctic.Unnatural noise, such as airguns, ship engines, pile drivers and sonar pings, can damage a marine animal’s hearing, mask underwater communication and disrupt critical activities, including migration. The cacophony is compounded in the Arctic by weather noise that was once dampened by the ice blanketing the ocean.

Marine mammals, such as whales, rely on acoustic signals to forage, navigate, find mates and guide other key behaviors. The excess noise from human activities shrinks these animals’ acoustic habitat – the underwater area in which they are able to communicate – and this can hinder reproduction and jeopardize the population’s survival.

The problem can be especially pronounced in the Arctic, where the noise is heightened by the uniformly cold temperature of polar waters. Sound travels over longer distances and is closer to the surface in the Arctic than in temperate oceans – relaying noise across the same depths at which Arctic marine mammals spend most of their time. As a result, noise from a ship engine can be heard dozens of kilometers away and blasts from seismic airgun arrays, which fire several loud pulses a minute to map the ocean floor for oil and gas deposits, are audible for hundreds of kilometers.

“The sound scenes that we’re imposing on the Arctic Ocean are profoundly huge,” said Christopher Clark, a bioacoustics researcher at Cornell University in Ithaca, New York, who has studied bowhead whales in northern Alaska for more than 30 years. The underwater noise levels from airguns, ships and offshore construction can be several times higher than the loudest natural background sounds. “The Arctic situation is critical because man-made noise activities have been relatively infrequent” until fairly recently, Clark said.

Silenced Songs and Thwarted Migration

The effect of noise on marine mammals is determined by a complex interplay of factors. Pitch, frequency, ambient conditions, distance, whether the sound source is moving and other specifics all influence an animal’s response to sound, said Brandon Southall, a bioacoustics researcher at U.C. Santa Cruz and the former director of the U.S. National Oceanic and Atmospheric Administration’s ocean acoustics program.

For example, bowhead whale communication can be disrupted by relatively low noise levels in two distinct ways depending on the total amount of sound they receive over time. A recent study published in the journal PLOS One looked at the reaction of bowheads in the Beaufort Sea to noise from airguns during oil exploration from 2007 to 2010.

But other activities, such as military operations by nations with Arctic borders, appear to be ramping up. And ship traffic will likely increase in places as the sea ice continues to recede.

“I think we’ve learned enough, and there’s been enough responsible development, that it can be done in ways that minimize the effects,” said Southall. For starters, governments could restrict noisy activities during the spring when females with calves are present, and enforce “exclusion zones” that require airguns to stop if species such as bowheads or beluga come close.

“There’s some informed and adaptive ways,” Southall said. “But they need to be supported in a combination of science and traditional knowledge.”

Ocean Noise Feature on California Public Radio

SEA Senior Scientist Dr. Brandon Southall contributed to a recent feature story on ocean noise and some of the monitoring in the Cordell Bank NMSanctuary. The story aired on KQED public radio in San Francisco and is online as the featured post at KQED Science: and the link to the specific post is: The radio story is embedded in the post and there is an audio player at the top. This feature was also included in it’s entirety on the California report on all NPR stations across the state this past weekend.

B. Southall and Expert Working Group Present: “A Risk Assessment Framework to Assess the Biological Significance of Noise Exposure on Marine Mammals”

An expert working group consisting of B. Southall, W. Ellison, C. Clark, and D. Tollit presented a poster summarizing a recently developed risk assessment framework to evaluate the potential significance of noise exposure on marine mammals. The poster was presented at the 21st Conference on the Biology of Marine Mammals in San Francisco. The abstract of the poster is given below and a full version of the poster is available here (or is available from

EWG Framework_SMM posterEWG Framework_FINAL poster

Developing objective and defensible methods to predict potential noise impacts on marine mammals is a very challenging issue with a rapidly evolving scientific basis. An expert working group of biologists, engineers, and acousticians developed a risk-assessment framework for evaluating potential effects of discrete noise exposures. The objective was to develop a systematic, analytical process using certain logical elements of previous assessment methods to predict effects on hearing and behavior, integrated with a biologically relevant framework in which to interpret the significance of those predictions. The scope was deliberately narrow in considering potential effects of seismic airgun surveys on Gulf of Mexico marine mammals. However, the intent was to derive an analytical process that could be both readily modified as new data become available and more broadly applicable. The resulting framework includes several important components: (1) ecologically relevant means of predicting animal distribution; (2) variance in animal density estimates; (3) behavioral aversion in animal movement models; (4) quantitative means of evaluating potential population consequences of disturbance (PCOD) relative to exposure magnitude and duration; and (5) risk-assessment methods that account for uncertainty in key parameters for evaluating disturbance as a function of biological and environmental context. The framework includes sequential stages consistent with current U.S. regulatory assessment methods and additional processes designed to provide biologically meaningful context to interpret potential responses. It benefited from and applied several parallel, recent advances in noise exposure criteria, PCOD modeling, and environmental risk assessment. It represents a significant step in evolving from relatively simplistic methods to more sophisticated approaches that consider biological, environmental, and contextual covariates. Applications of the analytical framework to several real-world scenarios are presented in terms of the framework’s performance and practicality, together with envisaged next steps for advancing the framework. Key progressions include incorporating increasingly sophisticated species-typical social structure, behavioral aversion, and habitat-selection parameters, into movement models and considering multiple noise sources over ecologically relevant spatial and temporal scales.


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.

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