**The title, authors, and abstract for this completion report are provided below.  For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**

 

 

Study of issues related to stream pH and lampricide treatments

 

Michael A. Boogaard¹, Jane E. Rivera¹, Terrance D. Hubert¹, David A. Johnson², Alex F. Gonzalez³, and Brian E. Stephens⁴

 

¹U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI, 54603

 ²U.S. Fish and Wildlife Service, Marquette Biological Station, 3090 Wright Street, Marquette, MI, 49855

 ³U.S. Fish and Wildlife Service, Ludington Biological Station, 229 S. Jebavy Drive, Ludington, MI, 49431

 ⁴Department of Fisheries and Oceans, Sea Lamprey Control Centre, 1 Canal Drive, Sault Ste. Marie, ON, P6A 6W4

 

Abstract

At the October 2001 meeting of the Lampricide Control Task Force (LCTF), two pre-proposals and two requests for studies related to pH and lampricide toxicity were presented and discussed. The LCTF proposed combining the studies into a single proposal. A subgroup of the LCTF was asked to develop a combined research proposal. This resulting proposal had the following objectives: (1) define the influence of pH and total alkalinity on the toxicity of niclosamide to larval sea lampreys (Petromyzon marinus); (2) investigate the efficacy of extended-length/low-concentration blocks of lampricides for killing sea lampreys and assessing safety for nontarget fishes; (3) provide agents with a system of defining lampricide concentrations lethal to sea lampreys (LC99.9s) for waters of significantly varying pH that maximizes mortality to sea lampreys while minimizing nontarget effects; and (4) investigate causes of suppression of pH during lampricide treatments of some streams. This report describes research conducted on Objectives 2 and 3 at the U.S. Geological Survey’s Upper Midwest Environmental Sciences Center. Completion reports on Objectives 1 and 4 have previously been submitted. In this study, 12-h and 24-h toxicity trials with the lampricide 3-trifluoromethyl-4-nitrophenol were conducted on larval sea lampreys at varying starting points within a simulated one-unit diurnal pH cycle. Predictive methods developed in this study indicate sea lamprey LC99.9s for 12-h treatments may vary by more than 2 fold depending on the starting point within a one-unit pH cycle while LC99.9s for 24-h treatments will vary by less than 1 fold under the same one-unit pH cycle. Based on these results, a 24-h treatment strategy would be more advantageous than a 12-h strategy both in terms of treatment effectiveness and nontarget safety.