Physiological and biochemical insights into the biology of marine vertebrates and the ecosystems within which they function

My research program combines the fields of lipid biochemistry and metabolism, energetics, comparative physiology and ecology of marine vertebrates to better understand their varied life history strategies and how they cope with, or may be constrained by, changing environmental conditions. We use a suite of tools ranging from biochemical tracers to tracking technology to whole animal energetic measurements, in conjunction with measures of other life history characteristics. A major goal of my program has been to use my studies on fatty acid (FA) metabolism and biosynthesis to understand deposition and processing of FAs from diet, in order to develop a relatively non-invasive method to determine diets of free-ranging marine and terrestrial animals from their metabolically active fat stores (quantitative FA signature analysis, QFASA). Knowledge of diets is critical to understanding animal energetics, trophic dependencies and life histories of individuals and populations; it is thus also a critical component to understanding food web structure, ecosystem dynamics and responses of animal populations to environmental change. Over the next funding cycle, we will advance the accuracy and precision of QFASA procedures using new statistical techniques, develop methodology to address questions stemming from real-life data, and compile these new tools into a published QFASA package in "R" that will be readily accessible to other investigators. These tools, validated with additional new captive studies, will be used in all of our other work. Building on our newly initiated studies in the North Pacific Ocean, we will use a combination of physiological sampling and positional telemetry techniques to examine the potential drivers of both real-time and carry-over effects on physiology in marine animals, and how variations in ocean climate, winter migration patterns, and foraging effort before and during the breeding season differentially or collectively affect future pre-breeding condition, reproductive investment, and breeding success. We will expand our studies using grey seals as a model species to examine sources and drivers of variation in lactation performance, juvenile survival and recruitment, and lifetime reproductive success, and we will examine individual specialization in resource utilization, its impacts on the ecosystem, and the influence of long-term (4 decades) environmental and ecological change on this large marine predator. My research program will also train a new generation of scientists across multidisciplinary fields. My research program will continue to provide critical insight into physiological process, individual fitness, population dynamics, and ecosystem function, and will have important applications to the conservation and management of free-ranging marine mammal, seabird, and fish populations.**