Undergraduate Abstract

Kelly Shook
May 1998

Effects of Recreational Use on the Virgin Spinedace (Lepidomeda mollispinis mollispinis) in the North Fork of the Virgin River within Zion National Park, Utah

A Thesis submitted in partial satisfaction
of the requirement for the degree of

BACHELOR OF ARTS

In

Environmental Studies Program
University of Nevada Las Vegas

by

Kelly Shook

Spring 1998

Thesis Adviser:
Environmental Studies Program
University of Nevada Las Vegas

ABSTRACT

The purpose of this study was to investigate the effects of recreation on the abundance and distribution of Virgin Spinedace in the North Fork of the Virgin River within Zion National Park. On May 18, 1994, the United States Fish and Wildlife Service proposed the species for listing as a threatened species pursuant to the ESA. The Virgin Spinedace is now being managed under a conservation agreement between federal, state, and local agencies. Data were collected using the net seining method during the months of May, June, July, and August of 1997. Sampling was done in six segments of the river. Three segments were located in areas of heavy recreational use and three segments were in areas of low recreational use. There is some suggestion from this study that flooding may have a differentially greater effect on adult Spinedace in areas of high compared to areas of low recreational disturbance, though the effect may also have resulted from repetitive flooding. Other features of the life history, population structure, or demographic characteristics of Spinedace may also be affected by recreational disturbance. In this study, density of adult Spinedace did not appear to be significantly different in areas of high compared to areas of low recreational disturbance, but a similar study by Sappington (1998) demonstrated differences in other aspects of the aquatic community when comparing areas of high to areas of low recreational disturbance. We conclude that recreation in the North Fork of the Virgin River in Zion is having a measurable effect on the aquatic community during the summer.