Markus Horning - US grants

The focus of this collaborative research project is on the behavioral and energetic adaptations enable Weddell seals to forage in the cold, dark, Antarctic fast-ice environment. To answer this question, hypotheses related to general foraging strategy, foraging location, searching mode, prey detection, locomotor performance, the cost of diving and foraging efficiency of free-ranging Weddell seals (Leptonychotes weddellii) will be tested. In addition, locomotor performance and behavior during diving to estimate the costs associated with hunting and the benefits gained from hunting (type and frequency of prey captures) will be examined. This study will provide unique insight into marine mammal foraging tactics and will contribute to fields of physiology (diving and energetics) and ecology (foraging theory and behavioral ecology). The proposed study builds on research on Weddell seals in McMurdo Sound using an animal-borne video system/data logger to record the behavior, physiology and locomotor performance of marine mammals at depth. This provided first observations of Weddell seal hunting strategies, predator-prey interactions and corresponding estimates of diving metabolism. The isolated-ice-hole protocol used in the study allows seals to choose the depth and duration of a dive, but they must return to a single place to breathe, which limits their range of movement. In addition, they are unable to haul out of the water or interact with other seals and may be exposed to lower prey densities than when foraging naturally. The new focus is the behavior and energetics of completely free-ranging seals, for which all significant constraints have been removed. Although the current study has demonstrated important new principles in Weddell seal foraging and has increased understanding of diving behavior and swimming performance, it is now essential to determine whether those principles apply to unconstrained animals. The study will continue to employ a multidisciplinary team of scientists with highly skilled technical support. The results will advance the understanding of the foraging ecology of Weddell seals and create a basis for similar research on other species of marine mammals that are more difficult to study in the open ocean. Finally, by extending the study from an isolated ice hole to completely free-ranging conditions, this research will provide new insight into the role of Weddell seals as apex predators in the Antarctic marine ecosystem.

The goal of this project is the development of a local area imaging network for polar regions that is remotely accessible via satellite high-speed data link. The primary purpose of this imaging network will be the performance of close-range three-dimensional photogrammetry for the remote determination of accurate spatial dimensions. By incorporating 3D-photogrammetry into the imaging system, the PIwill transform remote, close-range imaging from a simple observational tool to into a sophisticated quantitative tool for the accurate assessment of biological and physical systems in extreme environments.

The rationale for this system is a critical knowledge deficit of vital life-history
data on polar pinnipeds and seabirds. In northern regions, significant marine life management decisions are being made in the absence of adequate data. In the Bering Sea ecosystem in particular, apex predators such as Steller sea lions have declined to about ten percent of peak population levels. Despite years of intense research, hypothesized competition between marine apex predators and fisheries industry remains untested, predominantly for lack of viable research approaches for obtaining crucial life history data. Such data include frequent accurate census and age structure information in rookeries, as well as body mass and condition estimates of individual animals prior to, during and after fishing seasons. In a novel approach, we propose to use remote 3D-photogrammetry to significantly increase temporal resolution and numerical accuracy of remote census operations, to determine the age structure of rookeries through measurements of animals lengths, and to use photogrammetric volume determinations as estimators of body mass, in a technique recently validated by our laboratories. The proposed Satellite-Linked Data collection and Photogrammetric imaging system (SLiDaP system) will consist of initially four independent sub-stations, linked via wireless LAN to a fifth core-station. All stations will contain ultra-high-resolution digital still cameras and PCs, and will be independently powered by solar panels and batteries. The core station will be remotely accessible via an INMARSAT high speed data link. Key system design criteria will center around extreme ruggedness, highest reliability with minimal service requirements, low temperature capability, complete independence from any local power and communications infrastructure, rapid system deployment capability, as well as very low environmental impact.

Two prototype SLiDaP systems. The first system will be tested in Astoria, or for greater accessibility and early developmental refinement. The second prototype system will be tested under realistic field conditions on Ugamak Island, in the Aleutian Island chain.

This cooperative proposal between Texas A&M University Laboratory for Applied
Biotelemetry & Biotechnolgy and the National Marine Mammal Laboratory (NMFS), brings together leading academic research and marine resource management laboratories, as well as the industry leaders in photogrammetry and mobile archival tag design. Our efforts aredesigned to enhance basic biological research as well as marine ecosystem management. The proposed system will have applications far beyond our projected use: geologists, glaciologist and vulcanologist should profit from the availability of accurate remote close-range measurements for monitoring of shore degradation, land movement hazards, or volcano hazards to arctic air traffic routes along the Aleutians.

The primary objectives of this research are to investigate the proximate effects of aging on diving capability in the Weddell Seal and to describe mechanisms by which aging may influence foraging ecology, through physiology and behavior. This model pinniped species has been the focus of three decades of research in McMurdo Sound, Antarctica. Compared to the knowledge of pinniped diving physiology and ecology during early development and young adulthood, little is known about individuals nearing the upper limit of their normal reproductive age range. Evolutionary aging theories predict that elderly diving seals should exhibit senescence. This should be exacerbated by surges in the generation of oxygen free radicals via hypoxia-reoxygenation during breath-hold diving and hunting, which are implicated in age-related damage to cellular mitochondria. Surprisingly, limited observations of non-threatened pinniped populations indicate that senescence does not occur to a level where reproductive output is affected. The ability of pinnipeds to avoid apparent senescence raises two major questions: what specific physiological and morphological changes occur with advancing age in pinnipeds and what subtle adjustments are made by these animals to cope with such changes? This investigation will focus on specific, functional physiological and behavioral changes relating to dive capability with advancing age. The investigators will quantify age-related changes in general health and body condition, combined with fine scale assessments of external and internal ability to do work in the form of diving. Specifically, patterns of oxidative status and oxygen use with age will be examined. The effects of age on muscular function, contractile capacity in vascular smooth muscle, and exercise capacity via exercise performance in skeletal muscle will be examined. Data will be compared between Weddell seals in the peak, and near the end, of their reproductive age range. An assessment will be made of the ability to do external work (i.e. diving) as well as muscle functionality (ability to do internal work). The investigators hypothesize that senescence does occur in Weddell seals at the level of small-scale, proximate physiological effects and performance, but that behavioral plasticity allows for a given degree of compensation. Broader impacts include the training of students and outreach activities including interviews and articles written for the popular media. Photographs and project summaries will be available to the interested public on the project website. This study should also establish diving seals as a novel model for the study of cardiovascular and muscular physiology of aging. Research on Weddell seals could validate this model and thus develop a foundation for similar research on other species. Advancement of the understanding of aging by medical science has been impressive in recent years and the development of new models for the study of aging has tremendous potential benefits to society at large

A grant has been awarded to Texas A&M University at Galveston under the direction of Dr. Markus Horning for partial support of the development the Satellite-linked Data Acquisition and Photogrammetry (SLiDAP) system. The SLiDAP remote imaging network uses digital still pictures transmitted through a satellite data link, to reconstruct virtual 3D models of individual animals and their colonies. The development of the SLiDAP system was initiated to address significant gaps in the knowledge about many declining species of seals and sea lions in remote, polar regions. Specifically, information on year round trends in body condition and health of the Steller sea lion is vital to test the suggestion that a reduction in food abundance or quality, possibly related to extensive commercial fishing, may be contributing to the decline of this endangered species. Under this new funding, infrared cameras will be integrated into the SLiDAP system. Infrared cameras will allow users to remotely collect accurate temperature measurements on individual sea lions. The infrared images will be used to extend animal census operations into low light conditions, and to diagnose the health status of individual sea lions. The integration of infrared imaging into the existing SLiDAP system will be a substantial enhancement of the efforts to test the possible effects intense fishing on a declining marine mammal species.
To integrate infrared cameras into the SLiDAP system, several software and hardware elements of the system will be extensively modified. The software that controls the imaging system and allows for remote operations will be adapted to accommodate the new camera type. The glass viewport that allows pictures to be collected by cameras protected from a fairly extreme environment, will be modified to permit accurate temperature measurements, since the current design is not transparent to heat radiation essential to infrared imaging. The current ice removal system was developed by undergraduate students with Texas A&M University's Marine Engineering Technology department, and the revision of the system will also be carried out by undergraduate engineering students. Simultaneously, Dr. Jo-Ann Mellish and her student will calibrate the relationship between infrared signatures of individual sea lions held at the Alaska Sea Life Center, and the extent of body fat stored by the sea lions under their skin. This calibration will permit an accurate estimation of changes in the sea lions' body condition throughout the year.

The SLIDAP remote data collection network will open many inaccessible regions for long-term scientific observations that currently cannot be performed by other means, in addition to facilitating the collection of vital data on the biology of many animals species in a rapidly changing Alaskan ecosystem. The integration of remote temperature measurements will be a significant enhancement of the ability of the SLiDAP network to collect accurate measurements from animals and their environment. The development of a web-based multi-user shared access control interface for the SLiDAP network is being planned. Through this interface, the SLiDAP resource can be shared by many different institutions in different locations.

Oceans comprise the majority of the Earth's biosphere, and marine ecosystems are faced with profound changes driven by natural and anthropogenic factors, including resource extraction and climate change. Many upper trophic marine linkages remain unresolved, largely due to a lack of viable approaches for collecting life history and vital rate data from species that are often impossibly to observe directly. Essential data include age specific survival as well as causes of mortality such as predation. Such data are crucial to assess prevalence of top down (consumer driven) and bottom up (resource driven) effects, essential to our understanding of challenged marine ecosystems, but cannot yet be collected by single experimental approaches at comparable temporal and spatial resolutions.
Building on a successful proof-of-concept development that provided the first direct at-sea determination of predation on a marine mammal from post-mortem satellite transmissions, a miniaturized implantable life-long satellite monitor will be developed to provide high resolution data on mortality, predation and vital rates in marine homeotherms. The new Life History Transmitters are designed to be implanted into animals as small as sea otters, and will record vital data through the life of the host. Data on reproductive events and causes of mortality will be transmitted post-mortem via satellite. The new instrument will allow innovative experimental paradigms for the study of predator-prey relationships in multi-species upper trophic marine assemblages, and should lead to a surge in our understanding of complex marine ecosystems, upper trophic linkages and prevalence of consumer- and resource-driven effects.
This joint development will be led by Oregon State University's Pinniped Ecology Applied Research Laboratory, with Oregon State's School of Mechanical, Industrial and Manufacturing Engineering and Wildlife Computers Inc. (Redmond, WA), a leading manufacturer of marine vertebrate telemetry devices. Undergraduate and graduate students in the Computational Mechanics and Applied Design Laboratory will participate in the multi-disciplinary integrative application of technological innovation to promoting transformative biological research. The engineering students will design a programmable pressure-cycling dive simulator, as well as an antenna cover for the implantable device from advanced composite materials. Existing miniaturized satellite transmitter components will be modified by Wildlife Computers to allow the targeted size reduction to 50% (by volume) of the proof-of-concept device. Computational algorithms will be developed by the Pinniped Ecology Laboratory to allow determination of reproductive events and predation by the operational software of the devices.
Through a dedicated education and outreach package, the linkages between technological innovation and biological research will be brought to a broad public audience including potential users of the new instrument, other scientists, public people of all ages, as well as K-12 school children. The outreach package will utilize a purpose built exhibit at the Hatfield Marine Science Visitor Center in Oregon, a Sea Grant supported marine education venue serving over 150,000 visitors and 12,000 K-12 students, as well as a project dedicated web site (www.sealtag.org), and will provide specifically developed curriculum elements that meet National Science Education Standards and Ocean Literacy Principles. Curricula will be made available via the project website and to the wider Sea Grant audiences. After completion of the development, the new instrument will be made commercially available through Wildlife Computers (www.wildlifecomputers.com).

Despite being an essential physiological component of homeotherm life in polar regions, little is known about the energetic requirements for thermoregulation in either air or water for high- latitude seals. In a joint field and modeling study, the principal investigators will quantify these costs for the Weddell seal under both ambient air and water conditions. The field research will include innovative heat flux, digestive and locomotor cost telemetry on 40 free-ranging seals combined with assessments of animal health (morphometrics, hematology and clinical chemistry panels), quantity (ultrasound) and quality (tissue biopsy) of blubber insulation, and determination of surface skin temperature patterns (infrared thermography). Field-collected data will be combined with an established individual based computational energetics model to define cost-added thresholds in body condition for different body masses. This study will fill a major knowledge gap by providing data essential to modeling all aspects of pinniped life history, in particular for ice seals. Such parameterization of energetic cost components will be essential for the accurate modeling of responses by pinnipeds to environmental variance, including direct and indirect effects driven by climate change. The study also will provide extensive opportunities in polar field work, animal telemetry, biochemical analyses and computational modeling for up to three undergraduate students and one post-doctoral researcher. Integrated education and outreach efforts will educate the public (K-12 through adult) on the importance of quantifying energetic costs of thermoregulation for marine mammals and the need to understand responses of species to environmental variance. This effort will include a custom-built, interactive hands-on mobile exhibit, and development of content for an Ocean Today kiosk.

An award is made to the Alaska SeaLife Center (Seward, AK) to develop a miniaturized, implantable, life-long vital rate monitor for warm-bodied marine animals. This study will provide one postdoctoral researcher and a technical research associate the opportunity to participate in the multi-disciplinary integration of science and technology, and the application of technological innovation to promoting innovative biological research. Through a custom education and outreach package, the development efforts and linkages between technological innovation and biological research will be brought to a broad public audience including potential users of the new instrument, other scientists, public people of all ages, as well as grades 6-12 school children. The outreach package will enhance an existing, standards conforming STEM curriculum, downloadable from a project-specific website. Through addition of a geo-referenced data and information portal to this website (under development via separate funding, to go live in 2016), in combination with regionally available resources (distributed classroom activities kits) and remotely accessible training opportunities, modern science and technology learning opportunities will be brought to under-served rural classrooms in Alaska.

The purpose of the Life History Transmitter (LHX tag) is to determine survival, causes and locations of mortality of host animals. In female hosts, LHX tags also determine the age at birth of their first pup and the number of pups born over their life. Oceans comprise the majority of the Earth's biosphere, and marine ecosystems are faced with potentially dramatic changes driven by natural and human factors, including use of natural resources and climate change. Many linkages between causes of changes, and effects in complex marine ecosystems, specially those involving top level consumers as well as their predators and prey, remain poorly understood, largely due to a lack of feasible ways to observe many marine species that spend most of their life at sea or under water. To overcome this difficulty, a new monitoring device was developed under previous IDBR funding that enables the collection of predation, survival and female reproductive data by a single instrument, no matter where the host might move to, feed, breed, and die. Building on the success of this new telemetry device that provided the first direct at-sea determination of predation rates on a large marine predator from satellite-linked transmissions initiated only after the death of the host, this project will improve the capabilities and enable the production of the Life History Transmitter, for collaborative studies on many top level species of interest and concern. This will enable researchers from a broad community of potential users to conceive and apply new experimental designs to provide a major surge in our understanding of marine ecosystems, food chain linkages, as well as consumer driven and resource driven effects within the many unresolved knowledge gaps.

Marine animals must contend with ongoing environmental shifts and increased human activities in the ocean. Disturbances can affect the behavior of marine mammals, yet associated physiological costs remain unknown. Because their impressive capacity for diving is based on specialized physiology, it is likely that physiological costs limit and define the sensitivity of marine mammals to disturbances. This project will investigate variability of dive physiology in northern elephant seals by using experimental at-sea disturbances that elicit responses to noise - a stressor of global concern. The methods build on state-of-the-art logging technologies and will develop a new probe that will be capable of detecting oxygen management in the body. Cardiovascular physiology and oxygen use of the seals will be measured during routine diving, and compared with animals that experience a remote experimental disturbance while at sea. The project goal is to understand the physiological range and limits of this species, and to provide data that could predict marine mammal resilience to natural and anthropogenic stressors. These data will have wide-reaching implications for sensitive ecosystems and other species of concern that are not easily studied. It will be directly applicable to conservation and management of marine species and habitats. The project will train undergraduates, graduate students and a postdoctoral researcher, and will include extensive public outreach via state parks, and a public aquarium.

Environmental changes, including noise pollution, represent a fundamental challenge to the structure and sustainable function of marine ecosystems. The goal of this project is to identify physiological variability in the oxygen management of a diving seal that can be directly linked to individual success in the ocean. The project's three objectives will be achieved using at-sea data collected from translocated juvenile elephant seals, via integrated measurements of cardiovascular physiology (EKG and oxygen sensors in blood or muscle) with simultaneously collected time-depth records and 3-dimensional acceleration data to interpret underwater activity. Objective 1 will provide the first comprehensive picture of the dive phenotype in the open ocean by characterizing interrelationships among heart rate, blood oxygen depletion, muscle perfusion, and fine scale dive behavior. It will also assess molecular markers of perfusion capability in muscles with different underwater oxygen demands. Objectives 2 & 3 are based on experimentally inducing the behavioral effects of acoustic disturbance observed in many aquatic species - extended dive durations and increased cost of transport. Both objectives will examine oxygen management strategies in response to stimuli. Comparing natural versus perturbed dives permits an assessment of individual plasticity in the dive phenotype, incorporating behavior and physiology. This is a critical first step in determining the capacity of a model species to extend diving, their response to at-sea disruptions in natural dive patterns, and, ultimately, to predict thresholds of disturbance beyond which they cannot compensate.