My primary responsibility at IPHC lies in the development and implementation of ecological research to investigate the importance of halibut early life-history, behavior, and environmental forcing on spatial stock structure and recruitment patterns  in the northeast Pacific and southeast Bering Sea.  That's quite a mouthful, but more generally stated, my research centers on how life history traits affect halibut distribution and abundance, in both space and time.  That is, at any given point in time, a species is very rarely (if ever) found in equal abundance across its geographic range.  Rather, animals are typically found in patches of high population density surrounded by regions where relatively few individuals occur.  Similarly, population abundance does not remain constant over time, but often cycles between “good” years and “bad” years.  These are fairly simple observations: fishermen have know for thousands of years that fish and shellfish are found on separate grounds scattered along the coast, and that fishing is leaner in some years than in others.  The number of grounds, where they are found, and the manner in which they are positioned relative to one another  (i.e., the population's “spatial structure”) will be different depending on what species you're dealing with.  Spatial population structure is shaped by a species’ habitat requirements over its lifetime, the nature of the landscape that it inhabits, and interactions with members of its own species and with other species in the ecosystem.  For instance, animals may be found in a particular location while they are small, young, and vulnerable to predators, then move to important feeding grounds as they become older, larger, and more voracious.  At certain times of the year they may then move away from these feeding areas to congregate on different grounds for mating and spawning.  At each life-history stage, their habitat requirements may be very different: habitat that primarily provides shelter while young, habitat that provides adequate food supplies and favorable growth conditions when older, and habitat that facilitates congregation and egg-hatching during the spawning season.  For any particular species, the patchwork pattern that the population assumes (also known as "metapopulation structure" in some circles) will depend upon the unique life-history requirements of each age-class, where within the landscape each requirement can be met, and whether or not the location of critical habitats changes over time.

     In order for a species to persist, each age-class must be able to locate appropriate habitat and other members of its species at the appropriate time.  As humans who desire to harvest those animals, it is important that we understand the species' needs and movement patterns, so that we can avoid activities that might compromise spawning potential, disrupt movement between habitat patches, or isolate groups from the larger population in ways that make them vulnerable to local depletion or stock collapse.  In order to fully appreciate changes in halibut abundance over time, we need a better understanding of the factors that generate strong year-classes, how the population utilizes habitat at different ages, how animals move between areas on a seasonal and interannual basis, and how the population responds to fishing pressure and environmental changes.  Furthermore, because the environment is an ever-changing beast, we need to realize that the manner in which a stock is structured today may not be the way in which it was structured in the past or the way in which it will be structured in the future.  We need to keep an eye on environment and habitat, so we can understand and predict and how physical changes in the environment translate into changes in the abundance and distribution of the stocks that we harvest.

Logistically, this requires field work, and I have developed a halibut research program that blends a number of elements, including satellite tagging of adults, population genetics studies, and examination of juvenile biology and habitat use.  Much of the work has been inspired by discussions with fishers and other members of the fishing community who have a vast and rich experience with halibut biology.  For descriptions of my ongoing halibut research projects, which began in 2002, click on the "Ecological Research" link at the bottom of the page.  Or, to get a feel for how spatial stock structure can influence a population of marine animals and the fishery that harvests it, click on the "King Crab" link.  In a former life (and still in this one to some degree), I studied another highly prized and extremely tasty animal.
 

If you have any comments on this site, if any of the links become outdated or otherwise don't work, or if you would like other information that I might be able to help with, please feel free to email me at the above address.