Response for project 200204900: Eval Precision Bias Chinook
Comment on proposed FY 2006 budget
This project was incorrectly listed as being completed- it is not. Below I provide justification for the 2006 funding request of $57,256. The ultimate goal of this research is to provide guidelines for a statistically rigorous means of monitoring salmon populations by producing a relatively unbiased estimate of redd numbers with a valid measure of precision. Failure to fund will result in an incomplete and delayed analysis. CBFWA Funding Decision: Listed as a High Priority “RPA 180 - This ongoing research is allowing for the estimation of the precision that is associated with aerial and ground counts. The ability to identify the factors that could be influencing the precision of the counts is essential due to the fact that an aerial approach to counting redds is the only feasible method to count redds in the Middle Fork. The managers have identified this research as essential for future management activities.” BPA Funding Recommendation “Recommend as critical to implement RPA 180.” ISRP Final Recommendation “Fundable as amended with high priority. We note that success of this project apparently depends on funding some tasks in project #199902000.This is an excellent research proposal to evaluate biases and variation in common methods of conducting redd counts. The proponents appropriately identify their objectives as meeting the intent of Action 180 in the 2000 Biological Opinion that specifically calls for funding of Tier 1 and Tier 2 studies to collect data for population status monitoring. The insights derived from this research could have important applications for improving redd counts and assessing adult escapements currently conducted by other entities across the Snake River basin and, in fact, for the entire Columbia Basin.” NMFS Review “Well designed study, would produce important improvements in estimating populations. Very important work on measurement and sampling error associated with standard survey techniques (redd counts). Absolutely necessary for the development of accurate Tier 2 monitoring programs.”
Accomplishments since the last review
Accomplishments since 2002 In FY 2001 we submitted and were granted a request for a within year increase in funds as part of BPA Project #1999-020-00 to evaluate the bias and precision of redd counts which is our primary method for tracking Chinook salmon populations. In 2002, we submitted a proposal (#28001) to expand the redd count analysis research. In FY 2002, BPA Project # 2002-049-00 was funded and we expanded the research we had begun in 2001. From 2002 through 2004 we have annually collected field data that will enable us to rigorously evaluate the bias and precision of aerial and ground-based redd counts. In 2002, observers completed consecutive redd counts in 20 reaches of five major tributaries. Crews recorded the locations of all redds with GPS units. A total of 154 independent redd counts were completed in 17 reaches and IDFG biologists collaborated with us to complete 9 counts in 3 reaches. In 2003, observers completed consecutive redd counts in 15 reaches of six major tributaries. A total of 110 independent redd counts were completed in the 12 reaches and IDFG biologists collaborated with us to complete 9 counts in 3 additional reaches. In 2004, observers completed consecutive redd counts in 19 reaches of six major tributaries. A total of 131 independent redd counts were completed in 16 reaches and IDFG biologists collaborated with us to complete 9 counts in 3 additional reaches. From 2002-2004, variation in redd counts as a result of interobserver variability was examined by having multiple independent observers conduct single pass ground counts in several study reaches after the completion of Chinook salmon spawning. Reach- and redd-scale characteristics affecting sightability were measured by field crews at more than 800 redds from 2002-2004. These data have been assembled into a database in preparation for detailed analysis and modeling of factors affecting sightability. Results to date have been presented at Idaho chapter AFS meetings (Thurow and Isaak 2003), AFS National meetings (Thurow and Isaak 2004), and Western Division AFS meetings (Thurow and Isaak 2004). Several manuscripts destined for peer-reviewed journals are in preparation and Quarterly and Annual reports have been submitted to BPA.
FY 2006 goals and anticipated accomplishments
Deliverables that will be provided as a result of 2006 funds: 1-Spatially and temporally explicit maps of the true number of Chinook salmon redds in a series of study reaches. 2-Comparison of redd counts derived from both aerial and ground surveys. 3-A rigorous test of mark-resight estimators to evaluate the bias and precision of Chinook salmon redd counts. 4-A database of spatially explicit redd counts with a measure of interobservor errors of omission and commission. A model of factors influencing interobserver errors. A model of single versus multiple redd counts that includes a cost function in the analysis. 5-A database of spatially explicit habitat characteristics with the potential to influence redd sightability. 6-A model that assesses the influence of environmental and habitat variables on redd sightability.
How is this project consistent with subbasin plans?
Research Project #2002-049-00 evaluates the bias and precision of aerial and ground-based Chinook salmon redd counts in the Middle Fork Salmon River (MFSR) drainage and directly addresses the following Salmon Subbasin Plan Objectives and strategies: Aquatic Objective 2A: Strategy 2A1. monitor abundance and productivity of wild stocks- pg 23 Strategy 2A2. identify where there is a lack of knowledge pertaining to the population size of anadromous species- pg 24 Strategy 2A7. evaluate effectiveness of ongoing programs- pg 24 Aquatic Objective 3C: Strategy 3C1. quantify population specific adult abundance- pg 25 Strategy 3C3. determine population productivity- pg 25 This research provides the following “Key Performance Measures” cited on pages 125-127 as being critical for a Monitoring and Evaluation Plan: redd counts, adult size at return, adult run timing, adult spatial distribution, physical habitat, and water temperature.
How do goals match subbasin plan priorities?
On page 153 of the Salmon Subbasin Plan, the following statement is made: “The general agreement among the Technical Team members was that to conduct a scientifically valid prioritization, certain information that is not currently available would be needed …..”. Despite the widespread use of redd counts to calculate measures of population performance, little is known regarding the accuracy of aerial and ground-based Chinook salmon redd counts or the factors that decrease precision and introduce bias. Our research is validating the primary methods (aerial and ground-based redd counts) used to monitor populations and meet two of the listed needs (population-specific adult abundance and productivity key performance data). Similarly, our research directly addresses the methods used to meet needs for several of the “considerations for rankings” listed on page 154 (spatial structure, abundance, productivity, and diversity). This research also directly addresses key performance measures cited on page 26, specifically: 1) addressing key BIOP questions for research, monitoring, and evaluation and 2) providing unbiased and precise estimators of abundance and productivity targets. Further, this research addresses the methods used to meet identified research needs (pg 120) including performance measures of adult spawner spatial distribution and population growth rate (lambda). Finally, this research addresses at least three critical needs identified in Regional Program documents. 1) the need for long-term information to assess trends in wild Chinook salmon populations; 2) the need for evaluation of broadscale population sampling and inventory methods; and 3) the need for analysis of the spatial structure of wild Chinook salmon populations.
As noted above, this Project #2002-049-00 was incorrectly listed as being completed. Although all field activities will be completed in 2005, additional funds in the amount of $57,256 are requested to complete the analysis in 2006. This project relies heavily on Project #1999-020-00 to provide continuous aerial redd counts in order to asses the bias and precision of aerial and ground-based redd counts. This project was recommended for funding by CBFWA and other agencies at the following levels: 2002: $198,738/ 2003: $208,675 / 2004: $219,109 /2005: $219,109. All field studies will be completed in 2005. The 2006 request is for a reduction in funds to $57,256. The 2006 request includes only funds necessary to complete the analysis of the data collected from 2002-2005. Thank you for the opportunity to clarify and justify this funding request for 2006.