Author: Robert  Bailey,  Professor (Ontario Tech U)

Description:
Roger Green’s seminal work, Sampling Design and Statistical Methods for Environmental Biologists, has been cited more than 1400 times since its publication in 1979. It set forth clear guidelines for the design, execution, analysis, and interpretation of quantitative bioassessments, and had three foundational principles: 1. The Before-After-Control-Impact (BACI) design established a relative rather than absolute approach to detecting the impact of human activity on ecosystems. 2. Sampling effort, data analysis, and decision-making were firmly placed in a Null Hypothesis Signficance Testing (NHST), frequentist context. 3. Multivariate descriptions of biota were strongly favoured over indices, particular diversity indices, as response variables in bioassessments. Forty years later, despite the fundamental challenges of pseudoreplication and spatial and temporal autocorrelation, the BACI design remains an often unattainable gold standard of design of bioassessments. Bayesian approaches to analysis and decision-making have increased in popularity, but frequentist methods remain dominant. Multivariate characterization of the biota is common in bioassessment, indices and metrics are still both used and useful. We will examine the rational and irrational evolution of quantitative bioassessment over the last four decades, and suggest where progress might happen next.

Category: Scientific Program Abstract > Special Session > CS02 Management and Conservation of Aquatic Systems