Blue River Fish Barrier Monitoring 2014

Lower Blue River in Greenlee Co., Arizona was visited on October 28-29, 2014 to monitor fishes down- (Reach 1 – San Francisco confluence to barrier) and upstream (Reach 2 – barrier to Pat Mesa) of a fish barrier constructed by Reclamation and completed in June 2012. Fishes were sampled by backpack electroshocker from two fixed sites (one, 100-m site below the barrier and one, 200-m site above the barrier), two random 200-m sites above the barrier, and opportunistically. Nineteen pools > 1m deep were inspected from shore and underwater with mask and snorkel. Discharge was estimated at 10-15 cfs and water was clear. Weather conditions were ideal for both collections and snorkel surveys. Fishes overall were uncommon-to-common (30 to 144 per site) and catch rates were low (CPE 0.037 to 0.151 fish per second). Native longfin dace Agosia chrysogaster, Sonora sucker Catostomus insignis, and desert sucker Pantosteus clarki plus non-native red shiner Cyprinella lutrensis, channel catfish Ictalurus punctatus, and yellow bullhead Ameiurus natalis were captured below the barrier and native longfin dace, Sonora sucker, desert sucker, roundtail chub Gila robusta plus nonnative red shiner and fathead minnow Pimephales promelas were encountered above the barrier. Longfin dace, Sonora sucker, and desert sucker were seen but not enumerated during pool surveys, and no non-natives were detected. Several adult lowland leopard frog Lithobates yavapaiensis were seen; non-native northern crayfish Orconectes virilis was present but uncommon, and all were large individuals.

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