Marine Mammal Biology Program Research Thrusts
The following is a listing of research interest areas, or thrusts, for the Office of Naval Research's Marine Mammal Biology (MMB) program:
Monitoring and Detection
ONR's Marine Mammals Monitoring and Detection topic strives to improve marine mammal monitoring capabilities over current methods by developing new and existing technology such as passive acoustics, radar, and others. Recent research efforts on passive acoustics include the development and testing of new autonomous hardware platforms and signal processing algorithms for detection, classification, and localization of marine mammals. Ultimately, our goal is to adapt those algorithms for use on a variety of fixed, towed, floating, and profiling platforms. For example, over the last several years we have adapted the use of autonomous ocean gliders for marine mammal monitoring with the desired capability of persistent, autonomous, passive acoustic monitoring of an area for marine mammal presence to provide timely, reliable, accurate and actionable information to support marine mammal mitigation. A key goal of ONR sponsored technology development is making the technology available to the broader research and Navy communities.
Integrated Ecosystem Research
ONR's Marine Mammal Integrated Ecosystem topic seeks to understand the patterns and causes of variability in distributions of marine mammals over space and time. This topic often utilizes a multidisciplinary approach using tagging, visual surveys, and passive acoustics to collect baseline measures of marine mammal behaviors and distributions relative to environmental features & prey fields. Recent research efforts have focused on: using animal tagging and passive acoustic monitoring to study behaviors and distributions of marine mammals relative to key environmental properties (biotic and abiotic); providing a context for interpreting behavioral responses to external stimuli, such as anthropogenic sound; providing basic knowledge needed for predictive models of species of concern; and mapping prey in relation to physical features and marine mammal distribution.
Sensing and Tag Development
ONR's Marine Mammal Biology Program has had a long-term interest in both the invention and early stage development of new marine mammal sensing technology with the goal of improving our understanding of the behavior, distribution, and movements of these animals. Recent advancements in sensor technology and the on-going miniaturization of electronics components offer great opportunities to increase our capacity to monitor marine mammals. Additionally, attaching sensors or tags to cetaceans is particularly problematic and continues to be one of the greatest technological challenges hampering research efforts. ONR's Marine Mammal Sensor and Tag Development topic seeks to facilitate research through the development of attachment mechanisms covering short, medium, and long-term time durations; development of broad sensor suites into tags; and improving accessibility of sensors, tags, and attachments to the research community. A key goal of ONR sponsored technology development is making the technology available to the broader research and Navy communities.
ONR hosted a workshop March 16-17, 2009, to discuss tag design and attachment issues with researchers, tag makers, veterinarians, and the permitting agency. Download: Final Workshop Proceedings for the Cetacean Tag Design Workshop
Effects of Sound on Marine Life
ONR's Effects of Sound on Marine Life topic seeks to better understand and characterize the behavioral, physiological, and potentially population-level consequences of sound exposure on marine life.
Hearing:
ONR's Marine Mammal Biology Program seeks to understand how marine mammals hear, produce sounds, and are affected by anthropogenic sounds in the marine environment. Recent research efforts have focused on: looking at the anatomy of hearing; creating audiograms to determine what marine mammals hear; determining threshold shifts; comparing behavioral psychophysical responses with auditory evoked potentials. We are also interested in how natural and anthropogenic sound fields create masking effects – reducing the capabilities of marine mammals to detect and identify sounds of interest.
Behavioral Response Studies (BRS)
ONR's Marine Mammal Biology Program strives to safely study responses of marine mammals to naval sources and other anthropogenic sounds to understand and characterize the causal chain of events leading from sound exposure to "biologically significant" behavioral reactions that might increase risks of stranding. Recent interdisciplinary research efforts have focused on defining / characterizing behavioral effects of sound exposure on tagged whales and to measure the exposure required to elicit responses that are safe but indicate potential for risk. The MMB Program co-sponsors several major BRS-related field programs involving U.S. federal scientists and an international team of academic researchers, examining responses of marine mammals to carefully controlled exposures to sound in Southern California (SOCAL BRS) , Norwegian waters (3S Program), and several places in the Mediterranean.
Physiology (Diving & Stress)
Diving Physiology: ONR's MMB Program seeks a better understanding of the gas management and kinetics (stores and use) in marine mammals and the mechanisms that enable marine mammals to dive to deep depths for long durations while mitigating if not avoiding health threats. It has recently been suggested that diving mammals vary their physiological responses according to multiple stressors, which suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence or absence of gas bubbles to diving behavior. Also, technological advances in imaging and remote instrumentation would potentially benefit the field.
Stress Physiology: Marine mammals are exposed to a variety of potentially stressful anthropogenic and natural environmental inputs in both the wild and captive environments. Little is known about long-term effects of stress on individuals and populations in marine mammals. Prolonged exposure to stress may result in immune system suppression, reproductive failure, accelerated aging, and slowed growth. ONR's Marine Mammal Physiology Program seeks to develop an understanding of the natural variation of stress markers; better understand and characterize the relationships among hormones or other biomarkers in different matrices; define and compare the quantitative and temporal relationships of hormones across the different matrices; and evaluate / characterize the relationship between the physiological stress response in marine mammals and acoustic exposure and ‘biologically significant’ disturbance.
Population Consequences of Acoustic Disturbance (PCAD)
A major hurdle with marine mammal conservation and management is to know if and when measurable short term behavioral and/or physiological responses of marine mammals result in ‘biologically significant’ or meaningful effects on individuals and/or their populations. The NRC report (2005) presented the Population Consequences of Acoustic Disturbance (PCAD) model, which is a heuristic model that defines several levels of potential effects of anthropogenic sound on marine mammals ranging from behavioral effects, to effects on life functions (e.g., feeding, breeding, migrating), to effects on vital rates (e.g. adult survival, reproduction), to population level effects. Recent and future efforts of the ONR MMB Program on this topic seek to develop statistical tools to allow mathematical models of the population consequences of acoustic disturbance to be fitted to data from marine mammal populations, and lead collaborative development of transferable models of the effects of disturbance on marine mammals.
Models and Databases
The Office of Naval Research’s (ONR) Marine Mammal Models & Databases for Environmental Compliance topic seeks to provide tools to support environmental compliance efforts and decision-making. Recent research efforts have focused on the collaborative program "Effects of Sound on the Marine Environment" (ESME), which is a multidisciplinary acoustic risk model that captures the state-of-the-art science to estimate risk to protected marine life from sound exposure. Components of ESME have been integrated into the One Navy Model that is being used for all TAP II (and TAP III) risk assessment modeling to Environmental Impact Statements (EIS) for all naval activities worldwide. Future investment under this topic will include improvements or changes to the model to incorporate emerging scientific information in an open architecture/open business model system.