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o (.-'".J "',) (~ c.Ji ~t Implementation Program committee recommendation and the Biological Opinion for the Animas-La Plata Project. The Bureau of Reclamation has established an agreement with the Biological Resources Division of the O,S, Geological Survey to assist in monitoring the condition of the San Juan River trout fishery below Navajo Dam, The monitoring plan is designed to evaluate the effects on the trout fishery below the dam before, during, and after the 4-month flow test. Assessments to determine if there are any adverse effects related to fish crowding, or other forms of stress, will be conducted in two primary sections of the Navajo Dam tailwaters: between the dam to Texas Hole, and from Texas Hole downstream to the end of the quality water reach, Chronic stress will be measured using a series of sensitive histological, immunological and physiological tests, Angler surveys will monitor catchability of trout, Observers trained by the New Mexico Department of Game and Fish will interview fishermen throughout the 4-month test. The Department will also be responsible for monitoring trout movements by radio telemetry before and during the test. Trout feeding and food availability will be evaluated by examining stomach contents of individual fish and sampling the trout food in the stream. These analyses will help determine whether feeding activity by the fish is reduced by crowding and reductions in macro invertebrate populations, Assessments will also help determine whether crowding causes increased cannibalism of 3 to S-inch stocked fish, The San Juan trout fishery is maintained by stocking fingerlings on a monthly basis, To analyze the effect of reducing flows on the density and availability of macro invertebrates during the 4-month test, sampling before, during, and after the test will be conducted at three sites located downstream from Navajo Dam: 1) above Texas Hole, 2) below Texas Hole in the special regulation waters, and 3) below Texas Hole in the regular regulation waters, Samples will be collected during four sampling periods from October 1996 to October 1997, During the 4-month winter flow test, the Bureau of Indian Affairs will conduct an extensive water quality monitoring program, involving detailed water chemistries, physicochemical water measurements (e,g" pH, hardness, alkalinity, etc,), and bacteriological analysis on the San Juan River, The water quality data will be useful for both human health and ecological purposes, This study was developed in cooperation with the New Mexico Environmental Department, the Bureau of Land Management, the Bureau of Indian Affairs and several municipal water users on the river. - DOl -