Chinook Captive Brood Program
South Fork Nooksack Chinook Captive Brood Supplementation
The Chinook Supplementation project has two objectives:
1) to collect juvenile Chinook belonging to the South Fork Nooksack stock for a captive brood recovery program; and
2) using information from beach seining and the results from DNA analysis of captured Chinook to investigate life history patterns of juvenile Chinook Salmon in the South Fork Nooksack River.
Understanding the freshwater life history of juvenile Chinook is essential for implementing habitat restoration strategies that are effective in the recovery of the South Fork population. As of 8/31/10 we have collected 2,072 juveniles for a captive brood restoration effort to re-build the South Fork Nooksack Chinook population.
During the period from 9/18/07 to 8/31/10 we have captured 10,416 juvenile Chinook in the South Fork Nooksack using small beach seines. These are transported to the Skookum Hatchery were we collect a small DNA tissue sample from each fish to determine which belong to the South Fork population. DNA microsatellite analysis has assigned 2,072 (19.8%) of these to the South Fork Nooksack stock.
The captive brood program is a multi-agency effort. Field crews from the Lummi Nation and the Nooksack Tribe are responsible for collecting juvenile Chinook with beach seines. The Lummi field team has made 2,433 seine sets during this period at over 200 sites in the South Fork Nooksack. Beach seining is presently the primary means of collecting South Fork Chinook for the captive brood stock recovery program.
The Lummi Skookum Hatchery provides a place to hold juveniles during the week-long DNA test and is the site where mature adults will be spawned and their progeny will be reared prior to release. The Washington Department of Fish and Wildlife (WDFW) DNA laboratory in Olympia is responsible for the DNA testing to identify SF individuals. The WDFW Kendall Creek Hatchery and the National Oceanic and Atmospheric Administration (NOAA) Manchester Hatcheries are facilities used to rear juveniles until they mature.
Examination of beach seine catch data and the results of the DNA stock assignments for Chinook captured at these seine sites provides a glimpse into the early fresh-water life history of Chinook populations present in the South Fork Nooksack.
Chinook abundance, as measured by average catch per set for the beach seine, suggests that spring (March-May) and summer (June-August) are seasons of highest Chinook abundance. Fall (September-November) and winter (December-February) were seasons of the lowest Chinook catches. This is consistent with the large spring out-migration of Chinook in April and May recorded by Lummi NationÃ¢â‚¬â„¢s screwtrap in the lower mainstem.