Native fish conservation and management in the Upper/Middle Rio Grande, Pecos River, Canadian River, Tularosa and Guzman basins, New Mexico during 2011.

Authors: Evan W. Carson, W. Jason Remshardt, Stephen R. Davenport, Robert K. Dudley, Steven P. Platania, A. Monié

Year: 2011 (xliii)

Abstract

Native fish conservation in New Mexico is accomplished through long term monitoring of protected species, captive propagation, stream restoration, and interagency water management. Long term monitoring and research programs track many rare native desert fishes including Pecos pupfish (Cyprinodon pecosensis), Rio Grande silvery minnow (Hybognathus amarus) in the Rio Grande, New Mexico, and Pecos bluntnose shiner (Notropis simus pecosensis) in the Pecos River, New Mexico. The year 2011 can be generalized as a drier than average year and subsequently resulted in lower flows which negatively impacted native species. Further, prolonged low flows and river intermittency likely threatened all life stages in a variety of ways (e.g., desiccation, reduced resource availability, stress). Annual monitoring of the Pecos pupfish was done in core habitats in New Mexico following the finalization of the Pecos pupfish monitoring plan. Pecos pupfish were sampled at 13 sites in the Pecos River drainage of New Mexico from 11 - 15 April 2011. A total of 30,182 Pecos pupfish were sampled using between 20 and 40 traps at each site. USFWS, BLM, NM State Land Office, NM State Parks, and NMDGF participated in the monitoring. Multiple research and monitoring projects for Rio Grande silvery minnow continued in 2011 including population monitoring, population estimation, reproductive monitoring, and fish passage monitoring. Fall surveys are used to determine annual trends in abundance and distribution. The most recent survey data available is from October 2010. Rio Grande silvery minnow was collected in low numbers at the 20 sampling sites during October 2010 (N=137; 12,080.2 m2). This species comprised 3.5% of the total catch and was present in 63 of the 299 (21.1%) seine hauls that yielded any fish. Rio Grande silvery minnow was present at 15 of 20 localities. Population monitoring efforts demonstrated that Rio Grande silvery minnow density in October was significantly lower (p<0.05) in 2010 than in recent years (e.g., 2007, 2008, and 2009) but that it was significantly higher (p<0.05) than in 2002 and 2003. Reach-specific population estimates of Rio Grande silvery minnow in 2010 were highest in the Isleta Reach (N = 137,486) and lowest in the San Acacia Reach (N = 49,319). The standard errors associated with population estimates for the three reaches were proportionally comparable for the Isleta and San Acacia reaches; standard error was notably higher in the Angostura Reach. The overall population estimate was 267,272 and had a standard error [SE] of 99,338. The overall population estimate for age-0 (N = 115,166) Rio Grande silvery minnow was not significantly higher than for age-1 (N = 112,387) individuals. United States Fish and Wildlife Service (USFWS) continued monitoring of a rock channel fish passageway in 2011 for Rio Grande silvery minnow. PIT-tagged Rio Grande silvery minnow were released at various locations upstream and downstream of the passage in 2011. To determine if Rio Grande silvery minnow would use in-stream fish passageways, we implanted 6,657 Rio Grande silvery minnows with PIT tags and a used passive scanning station to document movements from seven release locations, up to 19.7 km upstream and 13.5 km downstream of the fish passage, and to document successful ascension of an in-stream rock channel fish passageway on the Rio Grande, Albuquerque, New Mexico. Between 18 March, one week after release, and 21 August 2011, 157 individuals were detected (2.4% of total), with 61.1% fish detected upstream release sites and 39.9% from downstream release sites.