Laserfiche WebLink
<br />e <br /> <br />001626 <br /> <br />e <br /> <br />The SJRlP is nm;v nearing completion of the second major attempt to compile, synthesize, <br />integrate and evaluate the mass of data collected. The first such effort came at the <br />conclusion of tht; 7 -year research period and is documented in Holden (2000). The current <br />major review is nearing completion of the compilation and synthesis stages, integration is <br />well undenvay, ;End the evaluation phase is getting started. To date, the deliverables <br />produced from this effort include final reports detailing the individual monitoring efforts <br />and a document which summarizes the monitoring results for the 1999 - 2002 period <br />(Golden and Holden, 2003). To meet the objectives for this study of hydrologic alteration, <br />I relied on these documents to briefly slunm~rize what appear to be the facts, as we know ~ <br />them today, about the condition of the San Juan River~ ~ ...dt= ~ '-~ .. - . <br />" <' '"""'""\~ <br /> <br />~he San Juan River fish commmuty has remained relatively stable' e IDce tion of the <br />SJRIP. (Ryden, ~~003; Golden and Holden, 2003; Holden, 2000) e predOID1n8I1t arge- <br />o' .: . een e' e sucker (Catostomus <br />lati'pinnis) and bluehead sucker (Catostomus discobolus) and the non-native channel .-At. <br />catfish (Ictalun.~s punctatus) and common carp (Cyprinus carpio). ~ ~pecie5: h3ve ~ <br />consistently comprised between 60 ~nrl 7~ percent of the catch annually, leading Ryden <br />- <br />(2003) to conclude that despite the flow manipulations and other management actions <br />initiated by the SJRIP, the riverwide proportions of these four species have remained qui~ <br />stable with no h,)ng-Iasting changes observed. Recent small-bodied fish monitoringlias J ~-- 0 . <br />continued to produce species and show tren similar to those seen d' e 1991 to - ~ ~ <br />. GJlden an 2003). Statistical analyses of primary channel sm - -. - J <br />bodied fish data have revealed no significant trends between years or reaches, and no <br />differences in elensi have eoo observed between ~ and secondary channel data. <br />The endangered species have been y rare captor ou out e period, ann Y <br />comprising les~:. than 1.0 - <br />2000 ~ e most encouraging data regarding the endangered species is the <br />escalating numbers of razorback sucker being . nt years b th al fis <br />"toring effl) Go en and Holden, 2003 Due to the stocking efforts now underway, <br />we are hopeful sub-adult and adult Colom 0 pikeminnow and razorback sucker will be <br />captured more: frequently in future years. <br /> <br /> <br /> <br />* <br />I~ <br /> <br /> <br />Physical habitat sampling has focused on temporal and spatial documentation of the <br />dimensions of the San Juan River channel, the condition of cobble bars suspected to <br />provide spaWl~.ing habitat, the composition and diversity 0 es" a e or ~ <br />use, and the water temperature regime' e, seve findings ap ar 0 e pro ematic <br />or reco e species. River crossrsection data suggest the channel <br />narrowing process, which began at least as early as the 1930's and ~elerated <br />by the closure of Nava" 0 . I' unabated (Golden <br />d Holden, 2003 By the late 1980's, the channel from Chinle Wash (RM 67) upstream to <br />Navajo Dam ( 224) had narrowed to 35% of the width measured in the 1930's (Holden <br /> <br /> <br />8 <br /> <br />E09-~ BIO/llO"d 99v-1 <br /> <br />-WOJ~ Wd61:10 EO-BO-l~O <br />