Evaluation of PIT tag antennae array & analysis of Humpback Chub PIT tag antennae data from the Little Colorado River

Duration

July 2011 - September 2014

Narrative

A key strategic science question (SSQ 1-8, Grand Canyon Monitoring and Research Center, 2007) is how can native and nonnative fishes best be monitored while minimizing repeated handling of fish. Managers wish to obtain population information in the least intrusive manner possible, especially when sampling the endangered HBC. Remote PIT-tag antennae have been shown to be very effective at continuous monitoring in other, generally smaller rivers and streams, alleviating the need for additional field sampling trips and multiple fish handling events. We propose to evaluate the efficiency of hoop-netting used for current monitoring compared to that of the new remote PIT tag antenna array, that does not require repeated handling of fishes, or additional field sampling in the Little Colorado River (LCR). PIT tags are already implanted in a large fraction of the adult population and to a lesser degree in the smaller life history stages of HBC in Grand Canyon. Antennae provide the opportunity to evaluate gear efficiency of hoop nets (e.g. what proportions of the fish present are captured), to increase precision of population estimates, direction and timing of movement within the LCR, and presence of fish in the LCR year round.

Research Products and Activities

Peer Reviewed Publications

• Pearson, K. N., W. L. Kendall, D. L. Winkelman, and W. R. Persons. 2015. Evidence for skipped spawning in the endangered humpback chub (Gila cypha) with implications for demographic parameter estimates. Fisheries Research 170:50-59
• Pearson, K. N., W. L. Kendall, D. L. Winkelman, and W. R. Persons. Tradeoffs between physical captures and PIT tag antenna array detections: a case study for the Lower Colorado River Basin population of humpback chub (Gila cypha). Fisheries Research 183:263-274..

Presentations

• Pearson, K., W. Kendall, D.L. Winkelman, and W Persons. Spawning probability of humpback chub, Gila cypha, in the Little Colorado River, Arizona. 2014 Annual Meeting of the Colorado-Wyoming Chapter of the American Fisheries Society, March 4-6, Laramie, WY.
• Pearson, K., W. Kendall, D. Winkelman, and W. Persons. 2014. Spawning strategy of the endangered humpback chub in the Little Colorado River with implications for estimability of demographic parameters necessary for species recovery. Society for Conservation Biology Conference, Missoula, MT.