WSP10539 - Laserfiche WebLink

Home Browse Search

I \0 an examination of the channel configuration since 1934 compared to rhe changes we have seen C:) during the research period, indicate that the general nature of the channel should not markedly ..... 'Q) change over what we see today for a very long time. Continued monitoring will help evaluate any 'Ut trends that may be of concern. No change in the report was made in response to this comment <:.Q There is increasing evidence that in addition to backwaters, main channel margins, especially in areas of complex point and lateral bars supply important nursery habitat for age 0 fishes. (e.g., Schiemer and Waidbacher 1992. River Cons. & Manage. Boon, Calow and Petts reds] and references therein). I believe these equate to the term "slackwaters" in Table 2.1. Have the contributions of these areas been investigated for larval and juvenile squawfish and razorback suckers in the San Juan or other Colorado River tributaries? RESPONSE: Yes, young squaw fish used low velocity habitats such as slackwaters in the San Juan River. This information is discussed on pages 3- 10 and 4-48. These channel margin habitats will be sampled more frequently under the proposed long term monitoring protocols being developed by the Biology Committee. Much of the fish sampling reported in Chapter 4, including specific species and life stages, was done by a variely of agencies (WDWR, NMGF, USFWS, USBR, UNM, etc.) using a variety of gears, various personnel, and at different times and flows within and among years. How standardized sampling protocols were for the same species and life stages among agencies within and across years is an issue that could influence interpretation of the results. RESPONSE: Standardization of collecting methods was implemented throughout much of the 7-year research period. The primary sampling factors that varied were sampling times and sampling intensity. We have noted this concern on page 4-40. 4-53, and other pages in Chapter 4. It is particularly important that any monitoring program instituted on the San Juan be consistent so that differences or similarities observed can be attributed to habitat, flow and species traits rather than gear or researcher variability. I'm involved in a 7 group consortium that has just completed sampling benthic fishes along the 3,300 kIn Missouri River for three years. We've used a set of standard operating procedures (SOPs) to accomplish this (to illustrate the approach they can be found at www.cerc.cr.usgs.gov/pubslbenfishltitle_page.hlm). While the details for the San Juan would differ greatly from the Missouri the need for standardization is evident. RESPONSE: We agree and have attempted to correct any problems with the Monitoring Plan that is presently being developed by the Biology Committee. I'm concerned at the amount of "grey" literature referenced to substantiate recommendations when many of these reports were completed several years ago. While it should not be the intent of this project to publish peer reviewed papers in professional journals, establishing scientific credibility of the research (e.g., Ryden and AIm 1996 on San Juan and numerous papers cited on Green and Yampa Rivers) is important if your recommendations are to be accepted by the various interest groups. RESPONSE: For one reason or the other, much of the Colorado River information has been reported in agency reports rather than peer reviewed journals. We have used peer reviewed citations as much as possible, but some information remains in final reportformat. Comments and Responses Flow Recommendations Draft Report Galat - 3