Science and Health

The Problem

Poor returns of Klamath River Stock Chinook salmon are severely limiting commercial fishing of salmon along the Oregon Coast. Coast-wide commercial fishing closures are limiting fishing opportunities to only a small fraction of traditional harvest levels. While Klamath Stocks are weak, other stocks are healthy. This fact raises several fundamental questions: Can Oregon fishers gain access to healthy stocks without impacting Klamath stocks? How can we help the fishing industry survive while Klamath stocks are down? Can genetic sampling for scientific, management and marketing purposes address some of these issues?

Combine genetic information with digital traceability systems to track Chinook salmon stocks and individual fish for management and marketing purposes.

A previous project (GAPS: Genetic Analysis of Pacific Salmonids) is developing a baseline for genetic identification of Chinook salmon. Each river basin has a unique genetic identity. Over 100 populations have been described thus far, allowing scientists to identify, with a high statistical probability, a harvested salmon’s river basin of origin.

This, along with knowledge of migration patterns may allow managers to reduce large area closures and allow access to healthy stocks without impacting weak stocks. The managers’ ability to realize these objectives will depend on where fish from different streams travel and feed, and whether they mix with other stocks or primarily associate with fish from their parent basin.

Fishermen are providing samples of tissue of legally caught salmon. These tissue samples along with information on oceanographic conditions and time and location of harvest, are mailed to scientists at the Hatfield Marine Science Center. By taking DNA samples from a small fin-clip (< 10 grams), scientists can use differences in patterns of genetic markers to determine the home basin (or hatchery) of an individual fish. By using the GAPS database and reliable sampling protocols, this can be accomplished in less than 48 hours, making the information immediately available for use in management decisions regarding the opening and closing of fishing areas. Genetic assessments will also be compared with coded wire tagged fish to test their reliability and effectiveness.

Fishermen are using on-board digital data loggers to record harvest location, depth, temperature, salinity and other oceanographic conditions.

Another scientific tool being used is to examine the chemistry of the fish’s otolith bones. The otolith is located in the inner ear and functions in balance. Otoliths grow rings like trees. As the otolith grows, certain elements are incorporated into the bone in proportions relative to their environmental concentrations. This can provide data on where the fish have been, and whether they travel together.
Fishing Locations

Map of the fishing locations
Figure 1.

Map presents proof in principal for fish caught in the June 4th, 2006 opener. Squares on the map located in accord with where each fish was caught (n=16, P>95%). Stocks: California Central Valley: Battle Cr, Mill Cr, Feather Hatchery sp; Columbia: Methow R, Wells H; Willamette: McKenzie H;South Puget sound: Soos Cr; Alaska: Babine R;Klamath: Klamath R Fall

Pie presents stock proportions for 71 fish that were assigned with P > 50%

A larger map is also available
Other possible uses for this Information

Using genetic information about a fish’s home basin can be used to market more abundant stocks and increase value to fishermen. For example, salmon could be marketed according to their home basin. This type of “branding” could increase salmon prices and create new niche markets of wild-caught salmon. Similar to how we identify certain wine traits and characteristics to different regions, we may begin to identify salmon sensory qualities with different river systems.