Field Testing of the In-Situ Toxicity Identification Evaluation (iTIE) System: A Novel Approach to Aquatic Restoration Planning

Abstract

The complexity of degraded streams coupled with the high expense of current restoration techniques calls for advancement in the field to reduce cost and better understand which chemicals are causing the most harm. The in-situ Toxicity Identification Evaluation (iTIE) system addresses these concerns by inexpensively and accurately identifying which contaminants are contributing the most toxicity in an aquatic environment. The iTIE system works by pumping polluted water through chemical sorptive resins to fractionate it into classes of chemicals (metals, PFAS, organics, etc.) before exposing the water to sensitive invertebrates and fish test organisms. These organisms are cultured and monitored for death and deformity compared to organisms exposed to unfractionated water and control groups. This study verifies the iTIE system’s compatibility with fish embryo-larval stage teratogenicity tests, a class of toxicity test protocols with wide applicability. Organism groups that experience high rates of death and deformity indicate exposure to contaminants of the greatest concern which is invaluable insight when creating a restoration plan. For this study four sites across Michigan were analyzed for restoration potential using the iTIE system: the Sexton & Kilfoil Drain near the Detroit airport, superfund site Clark’s Marsh in Oscoda MI, the Rouge River in industrial metro Detroit, and Fleming creek within the Matthaei Botanical Gardens as a control site. These diverse ecosystems provided strong case studies to validate the iTIE approach.