|Document Type:||Journal Article|
|Title:||Permanent thermal branding of coho salmon, Oncorhynchus kisutch|
|Author:||Alan B. Groves|
|Journal:||Transactions of the American Fisheries Society|
Coho salmon (Oncorhynchus kisutch), marked with thermal brands as juveniles, returned to their home hatchery as adult fish still bearing visible marks. This method of branding was previously described as a technique for short-term marking. Marked yearling coho salmon (15,000) were released in the spring of 1965 into the lower Columbia River from the Oxbow Hatchery of the Fish Commission of Oregon. Each fish was marked by removal of a pelvic fin and branded on the left dorsal surface of the body with the 6 mm letters, "FC." Six months later, 171 of the fish returned as 2–year-old adults. Their fork length had increased from 10 to 35 cm. Size of the visible brands had increased proportionally. Marks were similar to the original figures despite distortion from growth. The clipped fins permitted a double check of all the branded fish; all of the latter had visible brands.