Walt is an Assistant Professor at the University of Maine's School of Marine Sciences and a Research Scientist at the Gulf of Maine Research Institute (GMRI). Walt came to UMaine and GMRI after completing his Ph.D. at the University of New Hampshire in May 2010. Since then, he has been studying the energetic condition, spatial distribution, foraging ecology, age and growth of bluefin tuna and broadbill swordfish in the Atlantic. A key finding from Walt's dissertation was that tuna in the Gulf of Maine were skinnier during the 1990's.
Primary Research Interests
Highly migratory species (HMS), such as tunas, billfish and sharks, are some of the most fascinating animals on the planet. Species like Atlantic bluefin tuna, for example, have been important almost since the dawn of civilization. Described in detail by Aristotle, painted onto cave walls, stamped into currency, used as a food source and now a product in commerce there is probably no other fish with such prominence in our society. Crossing entire ocean basins, elevating their internal body temperature, swimming to depths in excess of 5000 feet within minutes and navigating with the precision of a GPS in an otherwise featureless environment is simply remarkable and something many HMS species do with regularity.
Globally, commercial tuna fisheries account for more than 33 billion dollars and including their recreational component exceeds 45 billion conservatively. While their value is high, our understanding of their life history is not. Plagued with uncertainty, stock assessments for HMS species often lack basic information like age structure, stock delineation, predator prey interactions, size at maturity, indices of abundance, basic sampling, fecundity and more. My lab’s research is applied, working on these and many other aspects of HMS life history to improve stock assessment models and reduce uncertainty in their current and future projections. Every project I have requires the participation of commercial and recreational stakeholders, without whose help and dedication this work could never be completed. People wishing to work in my lab can expect to get dirty and spend time on the water with the various fishery components. Doing both of these things will give you a better perspective and understanding for both the science and the fishery.
Walt works with a network of commercial and recreational fishermen in the US and Canada. These fishermen, who include sport fishermen and commercial fishermen on small and large boats, voluntarily provide information on the fish that they catch (where, when, and how big), and many of them return samples to Walt and his team of students. For each fish that is provided, his crew extracts its otoliths (small bones in the head) which record information about the fish’s life, much like growth rings record information about the life of a tree. Otoliths, together with other tissue samples, provide information on where the fish was born, its health, and what it has been eating
- Ph.D., College of Biological Sciences, University of New Hampshire
- M.S., College of Biological Sciences, University of New Hampshire
- B.S., College of Natural Resources, University of Maine, Orono
Service to Science & Community
- Academic appointment on the NOAA Highly Migratory Species Advisory Panel
- Full committee member, ICCAT Advisory Committee
- Regular contributor to the Standing Committee on Research and Statistics to ICCAT
These positions allow direct participation into domestic and international allocation and use of HMS resources. Appointment to these panels also gives Walt the opportunity to understand the most pressing management and scientific issues facing both our domestic and international management bodies. Opportunities in Walt's lab ebb and flow depending on available resources, but if you are interested we encourage you to reach out.