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essential habitat. It should be noted that only federal agencies are required to consult on proposed projects. Private and state development is not limited under Section 7 of the Act. CHANGES IN ABUNDANCE Changes in the relative abundance of woundfin within the Virgin River system are difficult to assess as few collection records are available for the early period of human settlement in the basin. Collections and field notes examined at the University of Nevada, Las Vegas, Brigham Young University, University of Michigan Museum of Zoology, and United States National Museum indicate the abundance of woundfin in the mainstream above Mesquite, Nevada has not appreciably changed since the 1930's. Woundfin populations in the mainstream below Mesquite, however, have declined. When C. L. Hubbs, (un- published field notes) collected P. argentissimus at Bunkerville, Nevada, in July 1942 (UNMZ 141655) he found it scarce but generally distributed in the main channel and more abundant in pools near the bank (which also con- tained C. latipinnis, P. clarki, G. r. seminuda and R. osculus). Today, P. argentissimus is the only native species usually collected below the water diversion at Mesquite, Nevada (C. latipinnis occurs only rarely in the lower river) and is much less abundant than the introduced Notropis lutrensis. The red shiner has nearly replaced woundfin within the modified habitat in the lowermost reaches of the river. LIMITING FACTORS The prime limiting factor for woundfin today is modification and loss of habitat. The building of dams and associated reservoirs, water diversion structures, canals, laterals, aquaducts, dewatering streams,, and the return of physically, chemically .and biologically (i.e., exotic species) polluted _ water to the main channel are the main contributors to this problem. With the human population increase in the desert southwest, the-loss of woundfin habitat will surely increase unless measures to protect its habitat are developed and implemented. CONSERVATION EFFORTS Since 1971, one of the major conservation efforts for woundfin has been the initiation of several studies relative to population disper- sion, community structure, ecological requirements, and abundance. Those studies were a result of funding by the U. S. Fish and Wildlife Service, the U. S. Bureau of Reclamation, the City of St. George, Utah, and the Interim Woundfin Recovery Team formed in Las Vegas, Nevada, in April, 1973. The official recovery team was formed in August, 1975, by a letter from Director Greenwalt of the U. S. Fish and Wildlife Service to team members. Other efforts have involved the Section 7 Consultations carried on by the Fish and Wildlife Service. 10 i