Darren Gillis

(Biology, University of Manitoba)

Information in fisheries data: insights into decisions on the water

Date Tuesday, October 21, 2008

Catch records remain the most extensive data on fish distribution and abundance available for analysis from commercial fisheries. However, these data are biased by the nature of fishing: effort in commercial fishing is directed and does not represent a random survey of fish abundance. This direction of commercial effort is possible through the information possessed by fishers, while the information that we can glean from their catches is biased by their choices. I will discuss both types of information in fisheries data through: 1) information based allocation of fishing effort, 2) specific biases in catch distributions resulting from fisher behavior, and 3) possible indices of movement developed from vessel position data. Ultimately, the decisions we make to manage commercial fisheries should consider the decisions being made by the fishers themselves, how they interact with our objectives, and how we can find evidence for them in the data that we collect. [Coffee, tea and cookies are served at 2:30, the talk starts at 2:45]