YKFP Spring Chinook Supplementation Assessment Anthony Fritts - WDFW

Quantitative Objectives of the YKFP Increase harvest opportunities. Minimize genetic impacts to unsupplemented streams. Keep impacts to non-target taxa within containment objectives. Protect productive habitat and increase freshwater productivity/capacity of Basin. Disseminate important scientific findings. Increase natural production of target species while maintaining long-term fitness. First go through the quantitative objectives of the YKFP. Will not show the actual numbers but these are what we use to help gauge the success of the program.

Harvest Tribal subsistence fisheries in the Yakima Basin have occurred in all years of the Program (1,191/yr). Sport fisheries in the Yakima Basin have occurred in 7 of the 11 years of HO returns (827/yr). Contributes to Columbia River Tribal, sport, and commercial fisheries (2,167/yr). Harvest has increased as a result of the supplementation program. Before the supplementation program, the Yakima River had not had a fishery since 1964 I believe.

Minimize Genetic Impacts Out of Basin spawning ground recoveries have been minimal. 2 Deschutes River, OR 2 Cowlitz River, WA 1 Wenaha River, OR 8 Naches River, WA Minimal strays detected in other populations.

Non-Target Taxa Robust monitoring program for non-target taxa of concern. See Gabe Temple’s talk tomorrow. Very robust monitoring program for NTTOC.

Habitat Habitat protection, restoration, and tributary passage efforts are ongoing. Several habitat talks today and tomorrow. Habitat work is important if we are to increase the capacity of the Basin.

See www.ykfp.org or www.efw.bpa.gov for reports Disseminate Data Many reports and publications have been produced by the YKFP. Many of the presentations today and tomorrow are YKFP efforts. Lots of data out there that others can access. See www.ykfp.org or www.efw.bpa.gov for reports

Natural Production and Fitness Talks by Andy Dittman, Curtis Knudsen, Chris Johnson, Steve Schroder, and Todd Kassler all relate to this topic. And so will this one…. These speakers will present data on mechanisms that can drive natural production and fitness and for this talk, I am going to show some preliminary results of some analyses to evaluate supplementation.

Indicators of Supplementation Success Total spawner abundance of the supplemented population should increase. Natural origin spawner abundance should increase. Productivity of supplemented population should remain the same or increase. So what needs to occur to allow supplementation to work? For one thing… Spawner abundance should increase due to proper hatchery practices increasing survival of fish released compared to naturally produced fish As a result of increased numbers of spawners, more naturally produced adults will return in future generations The productivity of hatchery fish and naturally produced adults does not decrease over time. Must account for changes in carrying capacity. Based on Monitoring and Evaluation of Supplementation Projects (ISRP & ISAB, 2005)

Objectives Estimate spawning escapement, proportion hatchery fish, and age composition of spring Chinook that spawned in the upper Yakima River and Naches subbasins Identify suitable reference streams by comparing productivity and abundance before the onset of supplementation (pre 2001). Use a BACI to test the deltas (T-R) in the pre and post supplementation years. What I wanted to do is calculate spawner abundance using methods similar to those used in unsupplemented stream type Chinook populations so that I could compare the abundance and productivities before 2001 to identify populations that track the upper Yakima. I could then use those streams to perform a BACI analysis to test for changes that may have occurred in the upper Yakima relative to the reference streams.

Spawning escapement YN conducts weekly census of redds from all available spawning habitat in both upper Yakima and Naches Use carcass recoveries adjusted for recovery probability bias based on Murdoch et al. (2010) to estimate sex ratio of the spawning population (i.e., fish per redd) Expanded total redds count by fish per redd to estimate spawning population. Sex ratios derived from carcasses were very similar and not significantly different to estimated escapement at Roza. Proportion of HO spawners derived from carcasses were very similar to and not significantly different than estimated escapement at Roza. Yakama Nation conducts weekly spawning ground surveys over the entire available spawning areas in the upper Yakima and Naches. I used methods from Murdoch et al. to adjust for recovery bias of carcass surveys so that I could then calculate the number of fish/redd. I then expanded the total redd counts by multiplying by the fish/redd to estimate the spawner abundance. I wanted to check my estimates to see of they were in the ballpark so I compared the sex ratios derived from the corrected carcass recoveries and found no difference to estimates derived from Roza data. I also compared the proportion of HO spawners from the carcass recoveries with the proportion that escaped past Roza and found no difference.

Potential Reference Populations Natural origin abundance (spawners) Correlation coefficient (r) P Bear Valley Creek 0.101 0.744 Big Creek 0.012 0.968 Chamberlain Creek 0.584 0.059 E.F. Salmon River 0.087 0.779 Lemhi River 0.309 0.305 Loon Creek 0.042 0.892 Marsh Creek 0.019 0.951 Naches River 0.928 <0.001 Secesh River 0.735 0.004 Sulpher Creek 0.133 0.664 Valley Creek 0.121 0.694 Data are from NOAA Salmon Population Summary database or YN (Number of spawners and age composition) Few streams correlated with Yakima for abundance. May be due to age structure (these streams have much higher proportions of age-5 adults than the Yakima but Naches and Secesh were similar) and potential population specific biases in estimating spawner abundance. We will continue to investigate alternate approaches to include only age-4 fish or only females.

Total Spawner Abundance Vertical black line denotes hatchery fish on spawning grounds. Pre data tracks reasonably well. Substantial increase in upper Yakima during supplementation.

Total Spawner Abundance BACI Results Population Origin Pre Supp T-C Post Supp T-C Post-Pre P Naches River All 794 3114 2320 <0.001 Secesh River 1124 3060 1937 Significantly positive increase in the upper Yakima during supplementation for both comparisons.

Natural Origin Spawner Abundance Much more variable without the HO spawners. Two years with a good bump but not so much for the other years.

Natural Origin Abundance BACI Results Population Origin Pre Supp T-C Post Supp T-C Post-Pre P Naches River NO 797 1359 562 0.113 Secesh River 1054 1544 490 0.314 Maybe a slight increase in the during supp period but no detectable difference in either comparison.

Potential Reference Populations Recruits/spawner (productivity) Correlation coefficient (r) P Bear Valley Creek 0.942 <0.001 Big Creek* 0.856 Chamberlain Creek 0.554 0.060 E.F. Salmon River 0.863 Lemhi River 0.615 0.019 Loon Creek* 0.634 0.015 Marsh Creek 0.753 0.002 Naches River 0.938 Secesh River 0.642 0.013 Sulpher Creek 0.262 0.366 Valley Creek* 0.552 0.041 So now lets look at productivity (R/S). Several good candidates for references. Big Creek and Valley Creek are small populations. Loon Creek had an extremely high R/S in BY1996 (>150).

Productivity (recruits/spawner) I just included the mean of the six references for ease of viewing. Productivity tracks really well in the before period and also looks so in the during period.

Productivity (recruits/spawner) BACI Results Population Pre Supp T-C Post Supp T-C Post-Pre P Bear Valley Creek -0.092 0.103 0.195 0.258 E.F. Salmon River -0.407 0.055 0.461 0.323 Lemhi River -0.112 0.125 0.237 0.536 Marsh Creek 0.064 0.152 0.088 0.562 Naches River 0.026 -0.078 -0.104 0.342 Secesh River -0.123 0.092 0.215 0.510 No detectable difference in any of the comparisons. Small decrease relative to the Naches. Few points in the post supp period 3 and 4 years.

Caveats (no conclusions yet) Preliminary results to demonstrate methods Recruits are not adjusted for harvest – could have implications where there are regional or temporal differences in exploitation. Need to correct for density – supplemented (or unsupplemented) streams may be above capacity, potentially decreasing freshwater productivity. Several good reference populations for productivity, but must continue examining other populations or develop other metrics for abundance. For example, recalculate spawning escapement using the same methodology. Few years of data during the treatment period. Likely need many more to make firm conclusions. YKFP will be working with other researchers in the Upper Columbia and lower Snake to refine methodology to assess supplementation programs

Acknowledgements All carcass and redd surveys in the Yakima and Naches are performed by YN Fisheries personnel. All data at Roza are collected by Mark Johnston and his crew with the YN. Bill Bosch maintains database and provided data. Andy Dittman with NOAA Fisheries provided additional carcass data for upper Yakima. BPA - Funding