Historical Perspective on the Development of Procedures for Conducting On-site Toxicity Tests and for Measuring Concentrations of Lampricides in the Sea Lamprey Control Program During 1957 to 1999

Abstract

Pretreatment static toxicity tests were used for three decades to determine safe, effective concentrations of lampricides applied to streams to kill sea lamprey ( Petromyzon marinus) larvae. The introduction of flow-through toxicity testing procedures greatly improved the accuracy and applicability of data generated in pretreatment toxicity tests, and provided a means of assessing potential effects of lampricides on nontarget organisms. Accurate, reliable methods of determining concentrations of lampricides in water have been a critical part of the program for chemical control of sea lampreys since its beginning. The use of colorimeters provided reasonably precise and accurate measurements of concentrations of TFM for three decades until the introduction of the Sequoia-Turner spectrophotometer. Recent standardization of methods among all treatment crews has resulted in a universal method of analysis that focuses on the quality of resulting data. Analyses for niclosamide, the active ingredient of Bayluscide, in water are more difficult due to the low concentrations (μg/L) applied to streams. After brief reliance on colorimetric and gas-liquid chromatographic methods, high performance liquid chromatography is currently used for all Bayluscide analyses.