Head of the Department, Professor, and Canada Research Chair in Physiology
My research program on integrative biomechanics addresses the general question of how organisms deal with physical challenges at the level of systems and structures. We study the biomechanics of locomotor systems in fishes, as well as the biomechanical basis of swimming, feeding, breathing, and diving in whales.
Fish and whale swimming: We study fast continuous and burst swimming in order to discover how muscle and skeletal systems perform in at maximal effort. Currently this involves measuring thrust production of hydrofoil lunate tails, a convergent feature of high performance fishes and whales. We are fabricating life-like tail models where size, shape and material properties are controlled, and direct force measurements made in simulated swimming experiments.
Whale feeding and diving. We are also expanding our research on biomechanics of baleen whales, particularly their adaptations for engulfment feeding and diving. We consider the scale of water engulfment, resulting energy cost and benefit, effects of size on feeding mechanics and feeding strategy, and how such large-scale feeding behaviour may have allowed or set limits to the evolution of the largest animals on earth. We are trying to integrate diving data, mathematical modeling of the engulfment process across a range of body sizes, and computational fluid dynamics and flow measurements on models of whale bodies and fins.
We are measuring the mechanical properties of jaws in order to understand how these bones meet the unique physical requirements for the extreme mode of feeding. Bone stiffness and mineral density are correlated by direct measurements. With a new method to integrate mechanical properties with cross-sectional shape and density along the bone we plan to create digital finite element models that allow virtual load testing of whole jaws of any size.
Whale arteries and lungs: The anatomical specializations in large whales are intriguing. We explore special features of the whale arterial system that are likely important for survival during deep diving. New experiments on the structure and mechanical behaviour of lungs and airways are being broadened to compare differences among whales related to dive depth. We are also studying lung structure and mechanical properties across a wide range of species, with new approaches to understanding breathing mechanics in live animal experiments, in conjunction with the Vancouver Aquarium.