Sour, ammonia-like, or strongly fishy smell
Slimy, sticky, or tacky surface
Dull, gray, brown, or yellow discoloration
Flesh that is mushy, soft, or falls apart easily
Dry, cracked, or excessively dried-out edges
Eyes that are cloudy or sunken on whole salmon
Gills that are brown, gray, or slimy on whole salmon
Belly area that looks bloated or damaged
Packaging that is swollen, leaking, or damaged
Expired use-by date
Left out at room temperature for more than 2 hours
Left out for more than 1 hour if the temperature was above 90°F
Freezer burn with severe discoloration or off odor after thawing
Any mold growth
Off taste after cooking
Presence of unusual texture or separation in the flesh