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132G Methods: Daily drift samples will be collected at two predetermined localities (Four Corners and Mexican Hat) starting in early July and continuing until the end of August. Nets will be set each day at dawn and dusk and left in the water for about two-hours. The amount of water filtered by each net (m3) will be measured by mechanical flow-meters suspended in the center of the nets. This information (m3) will allow us to determine catch per unit effort based on volume of water sampled versus time sampling. At the end of each two-hour net-set period, .the contents of each net will be rinsed into separate one-gallon plastic bags, labeled with unique field numbers, and preserved in 10% formalin. Drift material will be allowed to cure for at least two days before samples are processed and fishes separated from the debris. As we have done since assuming responsibility for this work, samples will be picked in the field. Unprocessed debris and cleaned samples will be returned to the laboratory for analysis. All fish specimens will be identified and counted. In addition, specimens will be assigned to more coarse categories such as "drift" and "incidental". The former category tefersto individuals with minimal or no control over their longitudinal movement. The latter classification refers to individuals whose developmental stage should have allowed them to avoid capture in passive drift nets. Collection data will be converted to catch rate and compared across and within sites by species. In addition, catch rate between and within sites will be compared across time. Specimens will be distinguished and compared by residence status (native versus non-native) and catch rate over- laid with the annual hydrograph. In addition to drift-net sampling at the two stations, we will coordinate with San Juan River researchers who are tracking the movements of Colorado pikeminnow in an effort to identify the putative spawning areas for that species. If adult Colorado pikeminnow are tracked to presumed spawning bars, we will establish study sites immediately downstream of those areas. Daily larval fish sampling, using MEC and other appropriate collecting devices, will be conducted for a 7-10 day period when larval Colorado pikeminnow are thought to be leaving the nests and beginning the drift portion of their life history. Products: Separate draft reports for the 1999 passive larval drift sampling activities and collection efforts downstream of the putative spawning bar will be prepared and distributed to the San Juan River Biology Committee for review by 31 March 2000. Upon receipt of written comments, that report will be finalization and disseminated to members of the San Juan River Biology Committee by 1 June 2000. Fish collected from those studies will be curated in the Division of Fishes, Museum of Southwestern Biology (MSB), Department of Biology, at the University of New Mexico. Original field notes will be retained in the Division of Fishes and collection information will be electronically stored in a permanent MSB database program. Electronic Work Plan FY99.wpd 8 Budget and Work Plan FY99 "---"'-;:-'~'" :'C--;C,~' ---",.,\,:-, <'--":,l;,;":,.\,,,,,-~-,_.,,,>.,~=.'.'C_,.o,,,,.,x,..;--. -- r ~'- ; ~ ' .; . .r l ,: t -;