Evaluation of salmonflies in Montana's rivers : are statewide populations really declining? Ee1b16f5-bb57-4522-9eb1-ece006bd5e00 Year: 2010 in 1977, 2000 and 2003. We have collected few salmonflies in the lower river since 2003 (Dan McGuire, pers. comm. 2010). Much of this data is collected as part of environmental monitoring within FERC operation and relicensing reports. The lower Madison population may be impacted by suboptimal habitat (thermal regime and substrate) during droughts. McGuire reports that neither Fraley (1978) nor Hauer et al. (1991) mentioned vascular plants in their site d
Evaluation of salmonflies in Montana's rivers : are statewide populations really declining? Ee1b16f5-bb57-4522-9eb1-ece006bd5e00 Year: 2010 in 1977, 2000 and 2003. We have collected few salmonflies in the lower river since 2003 (Dan McGuire, pers. comm. 2010). Much of this data is collected as part of environmental monitoring within FERC operation and relicensing reports. The lower Madison population may be impacted by suboptimal habitat (thermal regime and substrate) during droughts. McGuire reports that neither Fraley (1978) nor Hauer et al. (1991) mentioned vascular plants in their site descriptions, but describes 'Extensive beds (mostly Ranunculus) have existed from Norris to Cobblestone for at least a decade. This is a major habitat change!' McGuire's interpretation of the data and comments correlates with what we've been hearing about the salmonfly hatches below Ennis Lake, 'severely diminished to absent.' Greycliff Fishing Access has seen a 'complete loss of this stonefly taxa' from samples since the early 2000's. This scientific evidence also lines up with statements from long-time fisherman in our survey, 'The Lower Madison and Upper Madison river certainly seem to have lessened hatches, especially the Lower Madison, the hatch on the stretch from Warm Springs to Blacks Ford (below Beartrap Canyon) seems almost non- existent. The Upper Madison has been spotty, but it's a hatch that is always spotty.' According to the PPL consultant, the salmonfly populations in the Madison River below Hebgen Lake have appeared healthier the past few years, since the water levels in the lake and release flows have increased. The major cause of this stonefly decline in the lower Madison reaches is the often cited compounding factors of increased sediment levels in the cobbles due to drought or dam-induced lessened flushing flows coupled with warmer water temperatures; USGS gaged flows below Ennis have been below normal for 24 of the last 32 years (Figure ). Conclusion: Sa
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