Winning the cattail battle

Authors: Michael Davis, Steve Parmenter

Year: 2012 (xliv)

Abstract

Refuge persistence for Owens pupfish and Mohave tui chub, both federally listed endangered species, has historically been impacted by competition with non-native species and habitat loss. Early habitat modification methods aimed at recovery consisted, in part, of dam construction to provide isolation from non-native predatory fishes. This approach succeeded in avoiding the extinction of these species but did not lead to long-term refuge stability. Observations by our predecessors and us since 1969 suggest a link between increased water levels and loss of open water to dense emergent vegetation at refuge sites. Accompanying the spread of emergent vegetation was a perceived increase in non-native competitors and predators which were associated with population collapse. We have developed techniques to manipulate or replace emergent vegetation, leading to self-limiting plant communities, reductions in pest species, and longer-term viability for target species. This restoration model is applicable in both springs channels and ponds, and relieves some common problems encountered in the restoration of desert fishes and their habitats.