Northwest Fisheries Science Center


Dr. Linda Park
Project Lead
Staff Directory

Evaluating the effects of hatchery production on natural coho salmon in Minter Creek, Washington

In 2000, scientists from the Northwest Fisheries Science Center and the Washington Department of Fish and Wildlife initiated a collaboration to use DNA fingerprinting methods to estimate the relative reproductive success of hatchery and natural coho salmon spawning naturally in Minter Creek. Coho salmon have been released from the Minter Creek Hatchery since the 1930’s, with large scale releases starting in the 1960’s. For many decades, most of the naturally spawning coho salmon in Minter Creek originated from the Minter Creek hatchery. This is therefore not a study of a "pristine" wild population, but rather a study of what has happened to a natural population of coho salmon after approximately 60 years of intensive hatchery production. Results to date can be summarized as: 1) approximately equal reproductive success between hatchery origin and natural origin coho salmon in the stream, 2) an approximately 50% reduction in natural smolt production from the stream compared to 60 years ago, and 3) a clear trend toward earlier adult run timing in the stream.


Ford MJ, Fuss H, Boelts B, LaHood E, Hard J and Miller J. Changes in run timing and natural smolt production in a naturally spawning coho salmon (Oncorhynchus kisutch) population after 60 years of intensive hatchery supplementation. Canadian Journal of Fisheries and Aquatic Sciences, in press. (preprint available from Michael Ford –

Map of the Minter Creek watershed, with inset map of the Puget Sound region.  The Minter Creek watershed is located just east of the town of Purdy, Washington and feeds into Henderson Bay.  The map shows the two main tributaries of the creek, along with the location of the Minter Creek Hatchery near the mouth of the creek, and locations of two smolt weirs, one just upstream of the hatchery and another two a little further upstream. A figure illustrating the general approach taken to genetic pedigree studies. This illustration of a stream, with a weir at the mouth of the stream, illustrates how samples are collected across two generations.
(click to enlarge)