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Adults aggregate for spawning during April? June (approximately 93% of all recorded captures in the upper basin occurred during April? June; 25% in April, 54% in May, and 14% in June). Greatest concentrations occur between mouth of the Yampa River and mouth ofthe Duchesne River (GR RMI 344.8 to about 248.0). Areas of concentration include: mouth of Yampa River (spawning area, possibly post-spaWning recovery area), RMI 315?304 on the mainstem Green River (primary spawning area), mouth of Ashley Creek (GR RMI 294.0; pre-spawning staging area, possibly post-spawning recovery area), Old Charley Wash (GR RMI 249.6?249.4; pre-spawnmg staging area, possibly post-spawning recovery area), and mouth of Duchesne River (pre-spawning staging area, possibly spawning area, possibly post-spawning recovery area). Application of other sampling techniques, as alternatives to electro fishing, using fyke nets and trammel nets in certain confined and mainchannel habitats were initially tested in FY -1996. Captures of adult razorback sucker in 1996 in the middle Green River are summarized in Table 1. Sampling for adults in FY -1997, due to budget constraints, is limited to the Escalante primary spawning area, Old Charlie Wash area, and Duchesne and White River confluence area on the middle Green River. In 1998, areas sampled in the middle Green River during 1996 will again be targeted for weekly monitoring during late April?June (Table 2). Additionally, based on results of 1996 sampling for larval razorback sucker in the lower Green River, which strongly suggest that spawning occurred in that section of river, and results of the 2? 3 April 1997 ISMP meeting; . sampling for adults will also be conducted in reaches ofthe lower Green River during 1998 (Table 2). All fish collected will be counted, weighed, measured, their "condition" assessed, and returned alive to site of capture. Endangered fishes will be pit-tagged, and . scales will be collected from individual fish. The sampling period will be adjusted based on timing and duration of spring flows, onset of mainchannel water temperatures $ 140C, and temporal occurrence of adults. . Objectives 3 and 4. ? Monitor Relative Abundance of Larval Razorback Sucker in the Middle (Objective 3) and Lower (Objective 4) Green River: Summaries oflarval razorback sucker captures in the upper basin (1992? 1995) were presented by Muth (1995) and in the FY-1996 monitoring program scope-of-work. Results of 1996 larval razorback sucker sampling are presented in Table 3. Procedures for monitoring larval razorback sucker were developed in sampling conducted as part of the Flaming Gorge Research Program study to assess spawning success, larval distribution, and habitat selection of middle Green River razorback sucker, and National Park Service surveys for larval razorback sucker in Canyonlands National Park and Glen Canyon National Recreation Area. Sampling and specimen-handling methods will follow protocols established in these studies. In 1998, areas and periods with documented high captures oflarval razorback sucker will be targeted for sampling (Table 4). Light-trap sampling at night in low-velocity nursery habitats will be the prImary technique for monitoring. Light traps will be a floating, quatrefoil design commercially available from Southern Concepts in Birmingham, Alabama. Additionally, fine-mesh seines (I.6-mm or 3.2-mm mesh) will be used on a limited basis during daylight (also possibly at night) to document relative abundance of sympatric species not captured by light traps. Monitoring will be focused in the Escalante (RMI 319.4 ?301.7),Jensen (RMI 301.7?276.9),and Ouray (RMI 276.9?248.1) reaches of the middle Green River, and in selected habitats of the lower Green River within the Green River Valley (RMI 131.8 ?94.0) and Labyrinth Canyon (RMI 94.0?31.0) reaches. In the middle Green River, sampling efforts will be concentrated at Cliff Creek (RMI 302.8), Stewart DrainILake (RMI - 299.2?299.1), Page 5 of _