The purpose of this study is to identify the intrinsic and extrinsic quality characteristics of West Coast albacore tuna (Thunnus alalunga). Albacore tuna were troll caught off the Oregon coast and transferred to the Oregon State University Seafood laboratory in Astoria, Oregon. Core samples were extracted from six designated body zones of 16 fish and analyzed for lipid, moisture, protein, ash, and fatty acid distribution. Proximate distribution was constant throughout the body zones. Protein and ash made up 25% of the composition, lipid and moisture made up the remaining 75%. The lipid content ranged from 3.9 ± 0.2 to 36.3 ± 1.1%, with a distribution of higher lipid towards the head and lower lipid towards the tail. Total omega-3 content averaged 40% of the identified fatty acids for each body zone, with omega-3 (g/100g tissue) ranging from 2.1 ± 0.5 to 3.5 ± 0.4. Furthermore, an inverse correlation (R²= -0.95) was found for lipid and moisture content, enabling a faster estimate of lipid content derived from moisture content. Onboard handling techniques for West Coast albacore tuna were evaluated using sensory and analytical methods. Chilling (immediately and after 3 h), spiking, and bleeding at the throat and gills were evaluated by a sensory panel for overall quality, color, smell, texture and flavor. 2-Thiobarbituric acid-reactive substances (TEARS) and pH were also compared. Rapid chilling significantly and positively influenced overall quality, color, texture, and flavor; and significantly reduced oxidative rancidity. Bleeding at the throat significantly and positively influenced all sensory attributes tested, but did not significantly influence TEARS or pH. Neither spiking nor bleeding at the gills significantly affected sensory attributes. / Graduation date: 2003