Larval fish catches in the lower Milk River, Montana in relation to timing and magnitude of spring discharge

摘要: Larval fishes were sampled in the Milk River, Missouri River drainage, Montana from May to August 2002, 2003 and 2004 describe temporal spawning distribution relation spring discharge. Total larval catch-per-unit-effort (CPUE) 2002 (28.9 fish/100 m3) was an estimated 29 times greater than (0.99 fish/100 m3) 16 (1.78 fish/100 m3). In more one third of total catch occurred before 12 June whereas only 5% June. Marked differences species composition also observed between years, suggesting that a later peak discharge may benefit some earlier others. when flows peaked (at 77 m3 s−1), common carp Cyprinus carpio represented 37% catch. Common proportionally less abundant (7.2%) (1.4%) 2002. 2004, 163 m3 s−1) 32 days but 15 73 m3 s−1), shorthead redhorse Moxostoma macrolepidotum suckers Catostomus sp. numerically dominant taxa. These results indicate timing, not necessarily magnitude, influence success lower as indicated by fish catches. Copyright © 2008 John Wiley & Sons, Ltd.