Effect of Seasonality, Location, and Size on Lipid Content in North Pacific Troll-Caught Albacore Tuna (Thunnus alalunga)

Abstract

ABSTRACT Two hundred and thirty-nine albacore tuna (Thunnus alalunga) were troll-caught in the mid-Pacific Ocean and off the US Pacific Coast from June to November 2003. Catch location, harvest date, and sea surface temperature were recorded for individual fish, and lipid and moisture content in the white muscle were determined. The average weight of the alba-core was 6.07 kg and lipid content was highly variable (0.67–18.74%). There was an inverse correlation between the lipid and moisture content of albacore (R2 = 0.93), and percent lipid increased slightly in fish caught later on in the season (R2 = 0.24). Geographical Information Systems (GIS) software was used to determine correlations between lipid content and geographic location. Lipid content varied considerably among tuna caught at similar latitudes; however, most fish caught below 40°N had a lipid content of less than 10%, while the fish with the highest lipid content (13–19% lipid) were all harvested above 40°N.