Estimating Total Chinook Encounters using Catch Record Card-Based Estimates of Harvest

Background and Fishery Context

Based on agreements between the State of Washington and the Northwest Treaty Tribes, the Washington Department of Fish and Wildlife (WDFW) has been conducting pilot1 recreational mark-selective Chinook fisheries (MSFs) in the marine catch areas of Puget Sound since 2003. The goal of these fisheries is to allow increased angler opportunities on hatchery-raised, marked (adipose fin-clipped) salmon while limiting impacts on unmarked (adipose fin intact; typically wild origin) stocks of conservation concern, particularly ESA-listed Puget Sound Chinook. Given that anglers will encounter and then release unmarked Chinook during MSFs, execution of proper sampling and monitoring strategies is critical in order to assess catch rates and estimate impacts on wild stocks.

WDFW implemented the first recreational Chinook MSFs in the marine waters of Washington State in Areas 5 and 6 (Strait of Juan de Fuca) during summer 2003. In subsequent years, WDFW has implemented additional pilot-level MSFs in other Puget Sound marine catch areas (Areas 7 through 13; Figure 1) during both the summer and winter seasons (see Appendix A in WDFW 2012 for a list of areas and seasons). For example, the first winter MSFs were established in Areas 8-1 and 8-2 from October 2005 through April 2006 and have continued each winter season since. Additionally, beginning in 2007, summer MSFs were established in Areas 9, 10, 11 and 13 and winter MSFs began in Areas 7, 9 and 10. During the winter of 2010 (February through April), Chinook MSFs occurred for the first time in Areas 11 and 12 and have continued each year thereafter. Similarly, beginning in the summer of 2012, a Chinook MSF was established in Area 12 (South of Ayock Point), from July 1 through October 15. This steady introduction of new fisheries has resulted in an increase in angler participation in MSFs from an estimated 24,593 angler trips during the 2003-04 fishing season to more than 150,000 angler trips during the 2012-13 fishing season.