Technical Memo #1 Estimation of Returns of Naturally Produced Coho to the Klamath River Cramer Fish Sciences Nicklaus K. Ackerman Brian Pyper Ian Courter Steve Cramer

Objectives: Develop basin-wide estimates of run size to populate the initial brood cycle in the model. Develop population/reach escapement estimates for recent broods to allow partitioning of the coho run throughout the basin. Use run size estimates and partitioning system as reference points for future validation of model results. Tech Memo 1

Method 1 – Harvest Sampling Approach: Used captures of TRH origin and natural origin coho in Yurok Tribal Fishery, at WCW, and at TRH to estimate basin-wide run size. Evaluated Method 2 – Tributary Approach: Used best available information from individual populations/reaches to approximate run sizes in different portions of the basin. Evaluated Tech Memo 1

Trinity River Hatchery Iron Gate Hatchery Natural Harvest Sampling Approach Coho Enter River from Estuary in Late Summer - Fall

Trinity River Hatchery Iron Gate Hatchery Natural Yurok Tribal Harvest Sampling Tells Us Proportions of TRH, IGH, and Natural Fish In Estuary and Lower River Harvest Sampling Approach

Trinity River Hatchery Iron Gate Hatchery Natural WCW Tells Us Natural:TRH in the Trinity Change in TRH:Natural Ratios From Estuary to WCW Tells Us the Proportion Of Natural Fish in Estuary Moving Here CDFG Abundance Estimates in Trinity Allow us to Estimate Basin Run Size Harvest Sampling Approach

2005 WCW Removal 1999, 2000 WCW Removal 1998, WCW Removal Passage Timing of Coho at WCW

Harvest Sampling Approach

Harvest Timing in Yurok Tribal Fishery, Harvest Sampling Approach

Tributary Approach Estuary - Trinity

Williams et al. (2006) Historically Independent Populations: Lower Klamath River Middle Klamath River Upper Klamath River Shasta River Scott River Salmon River Upper Trinity River Lower Trinity River South Fork Trinity River Klamath Coho Life Cycle Model Reaches: Lower Klamath River* Middle Klamath River* Upper Klamath River* Shasta River Scott River Salmon River Trinity River *Mainstem and Tributaries are modeled seperately so that we may test effects of mainstem water management. Tributary Approach

Objective: Use the data available to generate rough estimates of abundance for each model reach. Method Limitation: Diverse suite of methods used inhibits comparison of estimates between reaches. Compounding assumptions affect accuracy and certainty around resulting estimates. Benefits: Provide approximations of run size where estimates were previously not available. Highlights areas where improved monitoring would be beneficial. Sum of estimates for reaches is useful for comparison to Harvest Sampling Approach estimates. Tributary Approach

Model Reach: Upper Klamath Mainstem Middle Klamath Mainstem Lower Klamath Mainstem Middle Klamath Tribs. Upper Klamath Tribs. Shasta River Scott River Salmon River Trinity River Lower Klamath Tribs. Primary Data: Mainstem Spawning Surveys Professional Judgement 2004 Bogus Creek Counts Shasta run timing and IGH entry timing Accounting of habitat availability Shasta Counting Facility Counts Redd and carcass counts Spawning surveys WCW Population Estimates Regional Juvenile Abundance Estimates Tributary Approach

2003 Passage Timing at Shasta Counting Facility Tributary Approach

Reach IGH Upper Mainstem100 Shasta Scott1,000-4, ,000-3,000 Up Misc Tribs1, ,5001,000-4,0002,500 Mid Mainstem0000 Salmon50 Mid Misc Tribs ,000-1,500 Lower Mainstem0000 Trinity3, ,0009,000 Low Misc Tribs ,000-2,000 Total7,000 – 10,0001,500 – 3,0007, ,00016, ,000 Tributary Approach

ReachBrood Cycle 1Brood Cycle 2Brood Cycle 3 Upper Mainstem 4%1% Shasta 4%2% Scott 2%1%*13% Up Misc Tribs 58%41%21% Mid Mainstem 0% Salmon 2%1%0% Mid Misc Tribs 10%5%7% Lower Mainstem 0% Trinity 20%42%48% Low Misc Tribs 1%*6%8% * Modified from Tech Memo to reflect that some spawners will be assigned to the reach. Tributary Approach

Run Size Estimates