Background

The proposed project is a direct outgrowth of our team members’ keen interest in using ecophysiological approaches to address marine conservation and resource management issues. Dr. Steffensen (University of Copenhagen) has led polar biology field classes to Greenland on several occasions. During these expeditions he has become aware of the Greenland shark bycatch issue. Based on what little is known of the Greenland shark’s natural history and population, it became clear that we were presented with a problem of a large and extremely slow-growing shark species facing high levels of fishing mortality. This is occurring not because it is a targeted species but rather because it is considered a nuisance bycatch species by a largely native population of fishers trying to eke out a living in one of the harshest environments on earth routinely occupied by human beings. Moreover, as very large, long-lived omnivores acting as an apex predator in a complex Arctic ecosystem, Greenland sharks may well have an important influence on all lower trophic levels. In other words, the health of Greenland shark population(s) may well be critical to the health of the Arctic ecosystem in general.

We intend to directly address the bycatch issue by testing the efficacy of electropositive metal as a shark deterrent, a method we have recently shown to be capable of reducing the catch rates of sandbar sharks on longlines by as much as two thirds. We also intend to use satellite tags to study the Greenland shark’s short and long term movements with the goals of (1) developing gear targeting strategies that reduce shark bycatch, and (2) increasing our understanding of the basic biology of this species. Finally, we will take the opportunity to collect shark tissue samples from fresh carcasses for preliminary age, growth, and reproductive maturation rate studies.

Aims and Objectives

The primary goal of this project is to test if recently developed shark repellent technology based on EP metal can be used on halibut longlines to the benefit of both the fishers and Greenland sharks. Secondly, we are interested in documenting the Greenland shark’s long and short term movement patterns by deploying popup satellite archival tags (PSATs).  Finally, we want to amass a collection of vertebral and other hard part samples from Greenland shark carcasses for age and growth analysis.