Acquiring data for large aquatic resource surveys: the art of compromise among science, logistics, and reality

The US Environmental Protection Agency (EPA) is revising its strategy to obtain the information needed to answer questions pertinent to water-quality management efficiently and rigorously at national scales. One tool of this revised strategy is use of statistically based surveys of aquatic resources such as lakes, wetlands, rivers, and streams. Implementing large-extent surveys involves decisions that reflect compromises between scientific rigor, consistent and practical implementation over large areas and many participants, and the realities of time and money Primary constraints result from interactions among management objectives, time lines, funding, and institutional constraints of participants. Secondary constraints arise from the interaction between the survey design (geographic extent, sample size, use of existing data), logistics (sampling period, sample shipping, information management, crew expertise, field training), and the Suite of ecological indicators selected (site-scale sampling design, field and laboratory protocols). We use our experience with the EPA's national Wadeable Stream Assessment and its Environmental Monitoring and Assessment Program Western Pilot Study to describe the key constraints and the resulting decisions made to implement those surveys successfully. The experiences from those surveys offer perspectives and information useful for effectively implementing future surveys of similar scope or spatial extent, including advanced planning, compatible survey designs, consistent methods, indicators, and cooperative research.