Reviews, narrative and other documents for proposal
201002800: Implement a Rotating Panel Sampling Adult Steelhead in Small Tributaries of the Tucannon and Snake rivers
ISRP final recommendation: Meets Scientific criteria? Response requested
In their response, the proponents for the most part, provided the information requested in the initial review. The response included a much clearer description of the rotational sampling plan, including details of trap construction and locations. The photographs were beneficial in visualizing the potential sampling capabilities and limitations outlined in the text. Methods were also proposed to evaluate stratified survey designs for redds. They clearly know their streams and the limitations of sampling methods for them. They justify the need to investigate these populations. The proponents have provided new data on fish densities and redd counts in their response. These data were informative, but it would have been helpful if the proponents had at least briefly interpreted these data. For example, it appears that Alkali Flats Creek had no observed redds and very few young salmonids. Is it on par with the others as a viable stream? It is not clear based on these data that it belongs in the sampling rotation. It would be a benefit for these studies to attempt to add observations and investigations on population behavior related to seasonal and life stage migrations and ephemeral use of tributary streams. Investigation of spawners is only the beginning. It may be equally important or more important to determine not only the locations and utilization by spawning aggregates, but also to determine where and when the juvenile fry and parr rear (summer and winter), and limits to their production. These streams do not appear to be productive rearing habitat in some years (or perhaps most or all years) due to low flow in summer (<1-5 cfs). This is also evident from the tables of fry and parr densities that were presented that fry densities seemed low, but parr were nearly nonexistent. The observed presence of resident rainbow trout, whether resident males or the progeny of hatchery strays (with possible negative impact to wild population genetics) also warrant further investigation. In general, questions related to genetic sampling and analyses were addressed in the response. Evidently the samples below and above Lower Granite will be analyses by the same lab. As they further refine their sampling design, they should seek input from a statistician. In general, they should think of their investigation in ecological terms and consider various life histories.
from Apr 2010 ISRP 2010-10 report
Narrative and other documents
|George Creek 1a.jpg|
|Coppei Trap 1.JPG|
|201002800 Response to ISRP no photo.doc|
|WDFWRotating Panel Sampling Proposal Narrative(1).doc (narrative)|
ISRP preliminary recommendation: Meets scientific criteria? Response requested
Overall, this proposal outlines a worthwhile effort to obtain information on often-neglected small population units or minor spawning aggregations (mSAs). Most other projects have focused on rebuilding larger population units. Smaller tributaries and their contributions are sometimes inadequately understood or neglected. In this proposal, it is important to have a clear plan of how the anticipated results for the mSAs will relate to the monitoring and ultimately management of the larger system as a whole. That is, what are the proponents expecting to find out in these smaller tributaries that will be important for the management of the larger Asotin and Tucannon steelhead populations? Because some of the mSAs flow directly into the Snake River, how will results from those tributaries be interpreted in relation to the actual Asotin and Tucannon steelhead? What are the actual relations between Asotin and Tucannon fish and these direct Snake tributaries? Is that issue addressed? To address these issues a response memo is requested. The title of this proposal as worded does not clearly or effectively describe the proposal. It confused each of the reviewers until the proposal itself was read. Although the term “rotating panel sampling” has gained some acceptance, it sounds more like a device rather than a sampling design. 1. Technical Justification, Program Significance and Consistency, and Project Relationships The proposal has presented adequate technical justification for investigating the contribution of small populations (mSAs) of Asotin or Tucannon tributary steelhead. The proponents also adequately made the case that the relative abundances of hatchery and wild steelhead need to be better understood in these mSAs. The significance to the Fish and Wildlife Program and its need for escapement data to properly manage steelhead populations was clearly described, as were relationships to related projects. The project is consistent with BiOp, RPA, and subbasin plan requirements and should yield data on possible effects of hatchery fish interbreeding with wild individuals in small tributaries. Working relationships with other groups appear to be good. For successfully achieving their objectives for the genetics component, it is not clear if the genetics sampling is solely opportunistic or if it has been well coordinated and linked with funded work from other agencies. It would be useful to present some evidence that the actual linkage has been established with the agencies that will analyze genetic samples, and that the need for them and importance of their analysis is recognized. Otherwise, the genetic samples may languish. 2. Project History and Results According to the proposal, “This is a new project, however exploratory steelhead spawning surveys were conducted several years ago in some of the tributaries included in this proposal. Steelhead spawning was documented in most of the tributaries, but a few surveys were inconclusive (Mendel et al. 2004, 2004b).” The results of all earlier work should be described. For example, what did those earlier surveys suggest as to actual or estimated abundances by creek/stream and how might those results affect the sampling design? Absolutely no numbers regarding expected or assumed sizes of steelhead populations are provided in the proposal based on those studies (i.e., Mendel et al. 2004, 2004b) so it is difficult for reviewers to gauge the level of understanding of the steelhead population trends or status in these streams. Is it possible that there are truly minimal numbers of fish in these streams? Or do they possibly have fish in some years but not others? It was difficult for reviewers to know the answers to such basic questions based on the lack of information presented. The optimal sampling design could depend on the anticipated and actual numbers of fish in the small tributaries, as discussed in Section 3 below. 2. Objectives, Work Elements, and Methods The narrative provided a reasonable technical justification for the adult monitoring proposed, which involved the trapping and sampling of tributary streams for adult steelhead abundance on a rotational basis, with location emphasis changing approximately every three years. There are some questions regarding justifying the best biological and statistical approach for meeting the monitoring objectives. As envisioned by the proponents, tributaries will be monitored for a few years, but the rotational approach will prevent the assembling of reliable long-term data series. It is questionable if this is the preferred approach, as opposed to, for example, maintaining some steady time series on the largest mSAs and just rotating sampling in what may turn out to be, based on preliminary analyses, the tributaries with the weakest runs? Some long-term index site sampling (including smolts out) with rotational random sampling may be a better strategy if viable mSAs exist. Which systems would these viable mSAs exist in? Or is that information not known? The concern is that under the proposed sampling design, no useful time series or patterns may emerge before in a particular stream before sampling rotates away from it. Have these alternative approaches (i.e., index or longer term versus rotational or mark/recapture snorkel surveys or aerial counts) been considered, and if so, what rationale was used for not recommending them? Some clarification would help here. It is assumed in the proposal that sampling will present no major problems. Temporary fish traps can be difficult to operate effectively in snow-melt systems. Population estimates may not be reliably obtained unless sufficient numbers are captured, marked, and recaptured. Some pilot testing may be necessary. Trap operations in the first year will very likely provide an indication whether or not this technique will work, or even be necessary, in particular tributaries. The proposed approach could be complemented by sampling for juveniles, via snorkeling or electrofishing. Are these approaches being considered? Secondly, beyond the biological basis, is there a statistical basis detailed for the specific rotation scheme proposed, (i.e., at least three years over a six to ten year period at five streams plus their tributaries on the Asotin and seven streams plus their tributaries on the Tucannon)? Because this approach is still experimental in nature on systems poorly studied, field results may influence the ultimate statistical design chosen. So for both reasons of sampling design and actual sampling, alternative methods should be carefully reviewed and considered. Objective 1 - Estimate the adult abundance and distribution of natural origin summer steelhead, as well as the proportion of hatchery steelhead, in currently unsampled portions of the Tucannon and Asotin steelhead populations The proponents indicate that that this approach “prioritizes the use of adult traps over spawning surveys.” This approach seems reasonable, but they should show that they have gone through an alternatives analysis and justified this approach. As the proposal is written, the proponents seem to want to do this as they go along. That is an acceptable approach, but some pre-design analysis would be helpful. In this regard, it would be helpful to have a description of the traps to be used as well as their documented successes and limitations from other applications. It would also be useful to have a better idea of the likelihood of washouts from high water, again based on other documented applications and comparisons of typical hydrographs. Objective 2 - Collect tissue samples from adult steelhead for baseline genetic analyses The approach outlines seems reasonable. Where and how will the data be stored? Is there a statistical basis for the number of samples to be collected? Has someone been identified and agreed to analyze the samples? What would be expected from the samples, and might it be of use in clarifying relationships among the Asotin, Tucannon, and direct-Snake tributaries being sampled, or just more broadly in relation to steelhead in other locations? Objective 3 - Compare steelhead spawning survey estimates of escapement with trap estimates, and test and evaluate several different spawning survey designs and determine their precision and accuracy. According to the proponents, the goal for testing different spawning survey sampling designs for estimating steelhead spawning escapement is to determine if spawning surveys could replace adult trap enumeration estimates in some Lower Snake River tributaries in the future and provide estimates of variance. Has there has been any juvenile assessment in the past that may be translated to adult escapement? Has mark-recapture with snorkeling been considered as an alternative? Have they considered this and other alternatives in any systematic way? More information on the specifics of the methods to be used would be very helpful, with appropriate literature citations. For this objective, the critical assumptions listed were: - That we will be able to successfully complete spawning surveys and accurate enumeration of redds for the entire spawning area, and spawning season, in at least one tributary where concurrent trapping is successful - That redds are accurately identified - That we can successfully georeference each redd locations - That enough redds will be documented to allow statistical analyses of several sampling designs - That WDFW staff in our Fish Conservation Section can complete the statistical comparison of several spawning survey design methods from our data collection in small tributaries of the Snake River and provide a final report "The probability of successfully addressing each of the critical assumptions associated with this objective is uncertain. However, we believe we have a good chance of success based on institutional knowledge and experience within WDFW, but we acknowledge that this objective is a test and has some probability of failure for some aspects." More could be done to address these critical assumptions in the proposal. For each assumption above, what are the factors that may or may not result in a given critical assumption being met? More detailed information on factors affecting redd counts in these systems would be useful. Some indication of the population sizes may clarify if enough redds are likely to be counted. Do the proponents have any particular survey designs in mind for the random draws? The proposal will contribute M&E data to regional data bases and is well positioned to do that. Annual technical reports are promised, to be subsidized by WDFW biologists' time. Regarding personnel, it is unclear what role Research Scientist Peter Hahn has in the project.
from Feb 2010 ISRP 2010-7 report