Population dynamics of Gambusia nobilis and Cyprinidon elegans in San Solomon Cienega, Balmorhae State Park, Texas

Authors: Kelbi D. Deluane, Raelynn Deaton, Gary P. Garrett, Chad C. Hargrave

Year: 2010 (xlii)

Abstract

Historically, Comanche Springs pupfish (Cyprinidon elegans) and Pecos gambusia (Gambusia nobilis) inhabited two large desert wetland (ciénega) systems in West Texas. However, human alteration of these systems for agricultural irrigation destroyed the associated wetland habitats, and endangered the persistence of Comanche Springs pupfish and Pecos gambusia. In an attempt to conserve these endangered species, the Texas Parks and Wildlife Department (TPWD) restored a critical desert wetland habitat by creating the San Solomon Ciénega at Balmorhea State Park in 1996 through a cooperative effort among private, state, and federal entities. As a result of this action the Comanche Springs pupfish and Pecos gambusia, have flourished in this location. In Fall 2009, TPWD created a second ciénega at Balmorhea State Park by replacing the small, refuge canal with a new ‘natural’ wetland habitat. Here we will report on seasonal monitoring efforts to document the establishment and development of C. elegans and G. nobilis populations in this new ciénega. We compare the population dynamics of these fishes in the new ciénega to the dynamics of these populations in the established ciénega. In general, seasonal populations in the established ciénega have been relatively stable since Spring 2008. Populations in the new ciénega were extremely low during winter ’09 and spring ’10 following immediate creation of the wetland. However, by summer ’10, populations of both species increased by an order of magnitude and reflect densities in the established ciénega habitat.