Laserfiche WebLink
<br />C~) <br />c::-> <br />fo-' <br />CD <br />(;J <br />-,} <br /> <br />Studies also showed that five irrigation and power plant diversion weirs in the upper river resulted in <br />barriers to upstream migration of native fishes. Plans to alleviate this concern at three of the weirs (Cudei, <br />Hogback, and PNM) were initiated in 1998 and 1999. <br /> <br />Portions of this objective that still need to be accomplished include legal protection for flows needed for <br />recovery (the SJRIP has approved flow recommendations and the Biology Committee developed them as <br />the flows needed for recovery), remediation of barriers to fish movements in the upper study area, and <br />investigation of potential temperature limitations in the upper study area, This objective of theLRP included <br />investigating habitat modification or restoration, The habitat and augmentation studies suggested that San <br />Juan River habitat was sufficient for some still unknown population level of the endangered species and that <br />large-scale habitat modification was not needed at this time, <br /> <br />IDENTIFY, PROTECT, AND RESTORE THE ENDANGERED FISH <br />SPECIES OF THE SAN JUAN RIVER BASIN AND MANAGE THE <br />NATIVE FISH COMMUNITY <br /> <br />Most of the SJRIP biological studies were targeted at this objective. These studies showed that the San <br />Juan River did not have a razorback sucker population and that the Colorado pikeminnow population <br />consisted of about 20 adults, RoundtaiI chub was also very rare and did not have a population in the main <br />stem San Juan River, Roundtail chub was common in some tributaries, but population densities in many <br />tributaries recently declined, Other native species were common to abundant. FlanneImouth sucker was <br />the most-common large fish in the river, and bluehead sucker and speckled dace were especially numerous <br />in the upper river where cobble substrates were common, FlanneImouth sucker populations declined in <br />all areas except Reach 6 during the 7-year research period, but even with this decline they remained the <br />most-abundant large fish, Life history aspects of the endangered and other native fishes were determined, <br />including location of Colorado pikeminnow spawning areas and habitat use information for both Colorado <br />pikeminnowand razorback sucker. This information was used to develop the flow recommendations and <br />to determine the importance of limiting factors. <br /> <br />The lack of a razorback sucker population initiated an experimental stocking study for the species. <br />The success of this experimental study led to development of a Razorback Sucker Augmentation <br />Plan in 1997, and augmentation began that year under Draft Genetic Management Plan guidelines. <br />Larval offspring of the experimentally stocked fish were captured in the San Juan River in 1998 and <br />1999, confirming that stocked razorback sucker in the San Juan River survived and reproduced, The <br />numbers of fish recommended in the augmentation plan were not stocked because of <br />difficulties in securing fish and rearing them to suitable stocking size. These problems are being <br />resolved, and the SJRIP developed three grow-out ponds for the species on BIA land near <br />Farmington, New Mexico, In 1996 and 1997, YOY Colorado pikeminnow were stocked to study <br />habitat use and retention in the river, Survival was good, and this experiment resulted in about <br /> <br />September 2000 <br /> <br />4-3 <br /> <br />Program Evaluation Report <br />