Wednesday, February 8, 2012

Staggering Numbers!

Twelve million! At first glance, a staggering number. Imagine twelve million of anything. It is the population of the states of Washington, Oregon, and Idaho combined. It is the amount of steps Martin Partell of Calgary, Alberta took to run 250 marathons in 2010. And it is also the amount of fish the Columbia River Fisheries Program Office Marking crew is going to be adipose fin clipping and /or coded-wire tagging starting February 22nd at Spring Creek National Fish Hatchery (NFH).

Spring Creek NFH is located approximately 4 miles west of the Hood River Bridge on the Washington side of the Columbia River. The hatchery was initially put into operation September 1901 to provide support for the commercial fishing industry. In 1938, it was reauthorized by the Mitchell Act and on August 8th, 1946, Spring Creek NFH was amended for conservation of fishery resources in the Columbia River basin. The hatchery facilities were later remodeled twice, first in 1948 as mitigation for Bonneville Dam and later in 1972 as mitigation for the John Day Dam Flood Control Act of 1950.

Starting in late August and running through September, adult tule fall Chinook return to Spring Creek NFH. Male and female salmon are spawned in September and upon fertilization, they are reared in trays within the incubation building. After reaching their fry stage, the Chinook are transferred outside to one of 44 burrows ponds in early January at an approximate population of 330,000 fish per pond. Here they are raised until the Marking crew arrives in late February to mark the population to be released as authorized by H.J. Res. 2 Sec. 138, which states that “The United States Fish and Wildlife Service shall, in carrying out its responsibilities to protect threatened and endangered species of salmon, implement a system of mass marking of salmonid stocks, intended for harvest, that are released from Federally operated or Federally financed hatcheries.”

Manual Trailer

Mass marking of this year’s Spring Creek release group will commence on Wednesday, February 22. As in previous years, the marking will begin in traditional manual trailers and finish in computerized “automatic” trailers. Mass marking refers to the removal of the adipose fin, a small fleshy fin located on the back of the salmon near the tail. The removal of this fin allows for the fish to be harvested when caught by a fisherman. In the manual trailers, the clipping of the adipose fin is accomplished by human hands. The juvenile salmonids are initially anesthetized, moved to a freshwater recovery bath , marked, and returned to the burrows ponds via a pipe leaving the trailer. 1.7 million fish are processed in this manner. Marking in the manual trailers will last about seven days and these fish will afterwards be transferred to Little White Salmon NFH for acclimation and an onsite release.

The primary reason for the use of the manual trailers is that at the time it is necessary to begin marking, the fish are not large enough to run through the automatic trailers. By Tuesday March 6, the salmon fry will have reached the average size of 65 millimeters in length to be processed by the automated trailers. In the Autotrailer, fish are brought into a holding tank, sorted by length to the nearest tenth of a millimeter, sent through a series of gates and sensors, and adipose clipped with a computerized system verifying a successful mark. The process is achieved without the use of any handling or anesthetic and upwards of 60,000 fish can be run through a trailer in an 8 hour shift. Three trailers running a double shift will be present and it will take approximately 6 weeks to mark the remaining 10.5 million fish.


A small percentage of fish will also have Coded-Wire Tags (CWTs) inserted into their snout. These tags are 1.1 millimeters in length, constructed of stainless steel wire, and are etched with a specific series of numbers that will not be duplicated. They remain within the snout for the life cycle of the fish and are scanned for electronically during hatchery spawning operations. The tags are recovered, the numbers read, and the data from the tag codes is used for the management of fisheries and the assessment of hatcheries, as well as other studies.

The CRFPO Marking crew would like to extend an invitation to the public to come observe the marking process. Visitor hours for Spring Creek NFH are on weekends from 7:30 AM to 4:00 PM. Manual trailer operations will be running from February 22 through approximately February 28 and automatic trailer operations will be going from March 6 through April 13.

Submitted by Geoff Gribble


  1. That's pretty cool Geoff! What kind of music do you listen to while playing with fish?

  2. WOW! Nice Post. I'll be up to see you at Spring Creek.