Developing a Long-Term Monitoring Protocol for the Pygmy Sculpin (Cottus paulus), a Spring Dwelling Imperiled Species

Abstract

Long-term monitoring protocols require adequate levels of precision in order to detect temporal changes in abundance or density. However, the ability to detect changes can be reduced by sampling variation, seasonal population fluctuations and environmental factors, such as habitat type. Using underwater observation, a monitoring protocol for Pygmy Sculpin (Cottus paulus) was developed and three sources of sampling variation were investigated: habitat type, seasonal variation, and observer effects. The Pygmy Sculpin is federally listed, threatened and is found in one just spring locality. The species is threatened by rising concentrations of trichloroethylene (TCE), which has contaminated the water supply, thus there is a need for a precise monitoring protocol. Pygmy Sculpin utilize habitat patches disproportionately, which causes an increase in sampling variation if habitat patch type is not accounted for in the sampling scheme. Pygmy Sculpin counts also differed among observers, and in most cases, experience did not influence counts. The resulting monitoring protocol was used over the course of a year to establish baseline data and to investigate potential seasonal fluctuations on the population.