Development of a Water-Quality Lab That Enhances Learning & Connects Students to the Land
Enos-Berlage, Jodi, The American Biology Teacher
Recent calls for change in undergraduate biology education have encouraged the development of curricula that focus on connecting science learning to real-world challenges (AAAS, 2009). The goal of such curricula would be not only to enhance science educational opportunities, but also to promote civic engagement. Assessment of such courses indicated that students made significant learning gains in multiple areas, including greater confidence and interest in science (Weston et al., 2006).
One of the major challenges facing humans worldwide is that of water quality. Recent assessments of rivers and streams in the United States indicated that 44% of them were impaired, the leading causes being pathogens, habitat alterations, and organic enrichment/oxygen depletion (U.S. Environmental Protection Agency [EPA], 2009). In Iowa, a major agricultural state, over 75% of assessed streams and rivers were impaired, including waterways in all 99 counties. Although one of the top sources of water impairments is agricultural activities, relatively few members of the nation's population have backgrounds that would provide them with substantial knowledge of agricultural practices (fewer than 1% claim farming as an occupation). The lack of familiarity with agricultural practices that affect water quality and the unique problems faced by agricultural producers poses challenges for developing an informed citizenry that will need to work cooperatively to address water-quality issues.
The goal of this study was to develop a microbiology laboratory curriculum module that would connect student learning to a real-life challenge, specifically a local water-quality project. Inherent in this goal was to have students experience an impaired watershed in multiple ways--by physically touring and observing agricultural practices in the watershed, sampling and testing water and soil, and interacting with landowners. The watershed would also serve as the venue by which students could learn about the major impacts of microbes in water quality and natural environments, including nutrient cycling. The intent was to create a laboratory series capable of serving a large number of students, expanding on the positive outcomes of involving undergraduates in water-quality-related research projects or dedicated courses (James et al., 2006; Koosmann et al., 2011). Significantly, although the lab module was specifically developed for a college microbiology course, it could also be adapted for use in general biology or environmental science courses at the college or high school level.
The primary focus of the laboratory series was the Dry Run Creek Watershed, a 20,172-acre sub-watershed of the Upper Iowa River that drains into Decorah, Iowa (see Figure 1). Dry Run Creek has been designated as impaired by the State of Iowa because of high bacteria levels, and a collaborative partnership that includes Luther College, Iowa State Extension, the Iowa DNR, and local landowners was recently formed in order to improve water quality. Undergraduate student research projects were developed to monitor water at 13 sites in the watershed. The educational benefits that emerged from this work provided the motivation to expand it to a larger number of students. Several of the established sampling sites were thus chosen for the laboratory series, on the basis of their contrasting adjacent land use. Stream site S1, located downstream of woodlands and a natural spring, and site S2, located downstream of a large, active agricultural region, were used for examining turbidity and bacterial levels. Stream sites S3 and S4 were used for nitrate analysis. S3 is relatively unique in the watershed because it primarily drains a large farm in the conservation reserve program (CRP). This land is planted in long-term, resource-conserving cover crops (e.g., perennial grasses) instead of annual agricultural commodity crops; CRP ground is not tilled, nor will it receive fertilizer applications for 10-15 years. …