Subject: Seasonal Changes in Energy Allocation by Walleye Pollock   (video)

Speaker: Ron Heintz, AFSC, Auke Bay Laboratory
When: Tuesday, 28 February 2006, 10 a.m.
Where:  Bldg. 4, Room 1055 “Observer Training Room,” Sand Point Campus, Seattle

Dear Colleagues: We’re pleased to bring you the fourth installment of this year’s AFSC Seminar Series, which highlights center-wide research relevant to the new “ecosystem” approach to management. Ron Heintz, of the Auke Bay Laboratory, Nutritional Ecology Lab, will discuss the dynamics of forage fish production by describing where populations obtain energy and how they use it.

Seasonal Changes in Energy Allocation by Walleye Pollock

Ron.Heintz@noaa.gov
Alaska Fisheries Science Center
Auke Bay Laboratory
11305 Glacier Hwy
Juneau, AK 99801

Abstract

In order to understand the impacts of climate change on fish populations it is necessary to relate population productivity to food availability and temperature through a common currency. At Auke Bay’s Nutritional Ecology Lab we employ analytical chemistry to determine where populations obtain energy and how they use it. These sorts of studies are particularly critical for walleye pollock owing to their commercial value and ubiquitous occurrence in the diets of whales, birds, seals, sharks, and other piscivores. Changing water temperature and zooplankton production are believed to be influencing the flow of energy to upper trophic levels. In order to understand how these changes might ultimately affect pollock populations it is necessary to understand how seasonal changes in energy availability influence the way in which pollock allocate energy. We examined the energy allocation strategies of young-of-the-year (YOY), juvenile and adult pollock collected quarterly from two locations in southeastern Alaska. Analysis of their chemical compositions allowed us to identify seasonal and ontogenetic shifts in pollock energy allocation strategies. This presentation will describe these data in addition to other ongoing studies designed to understand the dynamics of forage fish production from an energetic point of view.