Thermal Marking

Photo number 1. This is an otolith from a Brood Year 1992 Chum salmon from Gastineau Hatchery. It is recognized by the pattern of five dark bands close to the center (they resemble a racetrack). This fish is further recognized by an accessory mark of three thin close spaced bands near the edge of the otolith.

Photo number 2. This photo is a closer magnification of Photo number 1. You can see the five close bands and get a better picture of the three close outer bands.

Photo number 3. This otolith is from a Brood Year 1994 Sockeye salmon from Snettisham Hatchery. It has the same number of bands as the 92 Chum above, but the band spacing and width is different. It has the same five dark bands close to the center; however, the three close spaced bands follow immediately after.