Integrated Management of Sea Lampreys in the Great Lakes

1996 Annual Report to the Great Lakes Fishery Commission

TASK FORCE REPORTS

The Commission has established Task Forces to recommend direction and coordinate actions in several focus areas: St. Marys River Control, Sterile Male Release Technique, Barriers, Assessment, and Lampricide Control. The progress and major actions of the Task Forces for 1996 are outlined below.

ST. MARYS RIVER CONTROL TASK FORCE

• Task force (SMRCTF) established January 1992
• Charge is to develop a strategy for sustainable sea lamprey control on the St. Marys River that includes an integrated program of options that minimize costs and environmental impacts, while maximizing suppression of transformer production from the river over the long term.
• Members are Larry Schleen (Chair) and Robert Young, Department of Fisheries and Oceans Canada; John Heinrich, Dennis Lavis, and Terry Morse, U.S. Fish and Wildlife Service; Roger Bergstedt, U.S. Geological Survey, Biological Resources Division; James Johnson (Lake Technical Committee Representative), Michigan Department of Natural Resources; Richard Fleming (Outside Expert), Forestry Canada; and Gavin Christie, Commission Secretariat.
• Meetings held on March 4-6 and September 30-October 1
• Progress on the charge in 1996:
• Most of the key information-gathering studies required to make long-term control strategy recommendations were completed by the Agents during the field season. The extensive larval mapping project and estimate of the larval sea lamprey population were completed. The new granular Bayluscide formulation was tested for effectiveness in large-scale aerial applications. A rhodamine dye study was successfully conducted, and the computer flow model to predict the effectiveness of a TFM treatment was recalibrated and refined.
• The latest version of the control strategy timeline is presented in Table 23. The following statements summarize the 1996 actions and status of the control options and the information gathering tasks.

I. Control Options

A. Reduce Reproduction

1&2. Trapping of spawning-phase sea lampreys and release of sterilized males

These ongoing activities are reported in the assessment spawning-phase and sterile male release technique sections of this report.

3. Enhanced adult trap at the Great Lakes Power facility

The new trap was installed in phases. First, the trap was suspended from the bridge wall. The device was positioned to function as a passive trap, although it was not designed for this application. Two weeks of fishing produced no lampreys. The electrical installation then was finalized and the pumps for the water attractant were activated on July 5. During this phase sea lampreys were first observed in the trap, but catches were much lower than expected. The last phase, connection of the pipe between the trap and a holding tank in the nearby hatchery, began July 26, but no animals swam from the trap, through the pipeline, to the hatchery tank, perhaps due to the lateness in the season.

Modifications to this trapping system will be incorporated before the 1997 season. The proposed changes are designed to attract more adults into the trap, and to entice lampreys to swim through the pipe to the hatchery.

4. Enhanced adult traps at United States Army Corps of Engineers facility

Construction of these traps may be delayed due to Corps administration restrictions, but the Task Force recommends construction of the new traps in 1997, even if completion is too late for the spawning run. The Commission portion of the construction total ($42,000) was committed in 1996.

B. Reduce Larval Population

1. Section Bayluscide treatments

With the successful aerial applications of granular Bayluscide to large plots (3.25 hectares) in 1996 (see Information Needs section), most questions of efficacy and logistics of this option have been answered. No areas will be treated in 1997, but the Task Force will make recommendations on the scale of future treatments.

2&3. Section and whole-river TFM treatments

The Task Force will analyze the results of the dye study and the TFM transport model, coupled with larval distribution maps, before making a recommendation on this option. Scenarios for treatment of the north channel must be analyzed for costs and effectiveness before a treatment can occur. The timeline shows 1998 as the earliest a TFM treatment could occur.

II. Information Needs

1. Larval and habitat mapping

Background

A pilot study was successfully completed in 1992 which determined the feasibility of using a deepwater electroshocker and global positioning system equipment to take spatially referenced samples of the larval sea lamprey population in the St. Marys River and to map larval population density. This information is critical for planning and predicting the effectiveness and costs of treatment. The system incorporates geographically-referenced data on larval population density and data pertinent to predicting treatment effectiveness in a Geographical Information System database. At the direction of the Commission funds were reprogrammed for 1993-96 and work continued in 1996 to complete this multi-year task.

Table 23. St. Marys River Control Strategy - Timeline/Cost Estimates

Sampling Results for 1996

Systematic Sampling

Two areas were sampled in 1996:

• West Neebish Channel from Oak Ridge Point downstream to open water in Lake Munuscong.
• Middle Neebish Channel downstream through the Munuscong Channel to open water in Lake Munuscong.

A total of 68.30 km2 have been surveyed since 1993 (Fig. 10) including 12.27 km2 examined in 1996.

Currently, maps and estimates of the larval sea lamprey population sampled in 1996 are being made.

Generally, results indicate sea lamprey larvae are even less concentrated in the Neebish Channel than in lower Lake Nicolet. Small concentrations of sea lampreys were found near Hen and Chicks islands, but no other concentrations of larvae were identified.

The larval mapping project for the St. Marys River is complete. All known, significant, infested areas have been surveyed. An estimate of total stock abundance will be made upon completion of gear efficiency studies and analysis. Larval distribution and densities will be used to make recommendations on control options for the St. Marys River.

1. Larval Density and Lampricide Treatment Scenario Model

A proposal to develop a software interface between outputs of larval sea lamprey densities and treatment scenarios generated by the flow model was submitted to and accepted by the Environmental Management Technology Center, U.S. Geological Survey, Biological Resources Division, LaCrosse, Wisconsin. Completion and trials of the software interface are expected by June 1997. The interface will allow examination of effects of lampricide treatment scenarios on the larval sea lamprey population in the St. Marys River.

2. Index of larval abundance

Index sites were established to provide background information necessary to evaluate control operations. A total of 13 index sites were sampled in 1996. Four areas in lower Lake Nicolet and near Squirrel Island were added to those index sites sampled in 1994 and 1995.

3. Aging/transformation rates

A total of 88 recently-metamorphosed sea lampreys were collected from the St. Marys River in 1995 and 1996. These were weighed, measured, and dissected to determine sex and to remove statoliths for age determination.

Fig. 10. Area surveyed to determine distribution and abundance of sea lamprey larvae in the St. Marys River, 1993-96.

4. TFM Transport Model

The contracted computer flow model for predicting TFM transport under varying discharge and application scenarios was further refined in 1996. Results of the rhodamine dye study (below) and water velocity measurements collected by the Corps with Doppler sonar were used to refine and calibrate the model. The Task Force will utilize the refined model in conjunction with the larval mapping information to choose and recommend the most cost effective use of TFM to control larval sea lampreys in the north channel.

5. Dye Study

The rhodamine dye study was conducted to validate and calibrate the TFM transport model and to provide empirical data for exploring the feasibility of a lampricide treatment. The model predicted that a treatment of the north channel might be effective with a single-point application of lampricide through the Great Lakes Power (GLP) generating facility. The model also indicated that an effective treatment of the south channel (Lake Nicolet) is not economically feasible.

The Wisconsin Central Railway trestle upstream of the GLP facility was selected as the dye application point (Fig. 11). The plant turbines provided effective mixing of the dye. Thirteen transects were selected downstream of the GLP for sampling to measure concentrations of dye in the block. A sampling protocol was developed incorporating Global Positioning System coordinates to locate sample sites.

The study was conducted on August 10-11, 1996. The total river discharge requested for the study was 1,700 cubic meters/second (cms), which is close to treaty minimum and a realistic discharge for treatment. However, due to the high level of Lake Superior and the inability of some hydroelectric companies to reduce flows during the study, total discharge was 2,180 cms. Discharge at the application point averaged 1,020 cms with the remainder of the flow split between the compensating works (100 cms), the Corps hydroelectric facility (310 cms), the locks operations (10 cms), and Soo Edison hydroelectric facility (730 cms).

Department personnel applied 413 liters of dye in 14 hours at a target concentration of 8 mgl-1 (total product). The dye was well mixed immediately downstream of the GLP. A total of 2,400 water samples were collected to monitor movement of the dye block during a 2-day period.

Results of the sampling were plotted with areas that achieved more than two-thirds of the application concentration for 9 hours considered effectively “treated.” The results indicate that a lampricide treatment, under similar flow conditions, would be effective only downstream to Little Lake George. Effective treatment of the entire north channel would require a longer application and/or a different discharge regime.

Fig. 11. Map of St. Marys River showing the rhodamine dye application point, transect lines, and area of effective dye coverage during the dye study of August 10-11, 1996.

6. Section Bayluscide studies

At the direction of the SMRCTF, populations of sea lampreys and nontarget organisms were assessed in six 3.25-hectare plots in the St. Marys River in 1996. The plots were located in Lake Nicolet (four plots) and in the turning basin in the St. Marys River (two plots). A new bottom release formulation of Bayluscide was applied at 175 kg/hectare (5 lbs. active ingredient/acre) by a commercial pesticide applicator with a helicopter on July 12 and September 9. Applications were split between the two dates to allow assessment of the efficacy of the granular formulation of Bayluscide at two water temperatures (14 and 18o C). Post-application assessments were conducted to determine the effects on the populations of lampreys and nontarget species.

Deep-water electroshockers (DWS) were used to sample live larval sea lampreys and nontarget organisms on the stream bottom. Long-handled dip nets were used to collect lampreys and nontarget organisms at the surface. A minimum of one boat was assigned to each plot with a second boat assisting periodically in collection efforts. An underwater video camera, mounted on a remotely operated vehicle, recorded dead lampreys and nontarget organisms observed on the bottom.

Sampling

Pre-assessment surveys were conducted by DWS before the application of Bayluscide to determine the density of larval sea lampreys. Post-assessment surveys were conducted by DWS, dip net, and underwater video camera after the application to assess the effectiveness of the Bayluscide formulation.

A total of 3,396 kg of granular Bayluscide formulation was applied with each plot receiving 566 kg. The Bayluscide granules appeared to be well targeted and evenly spread.

Pre-assessment

A total of 578 larval sea lampreys and 2,719 nontarget organisms were collected by DWS. The nontarget organisms represented 9 taxa of macroinvertebrates and 5 genera of fishes.

Post-assessment

Live animals collected by DWS included 195 sea lampreys and 6,316 nontarget organisms. The organisms again represented 9 taxa of macroinvertebrates and 5 genera of fishes. An additional 1,073 sea lampreys and 53 nontarget organisms were collected during 15.45 boat collection hours. Thirty-two dead lampreys and 17 dead nontarget organisms were seen during 7.2 hours of observation with the underwater video camera.

Highlights

• The applications of Bayluscide did not cause extensive mortality of nontarget organisms within the plots.
• No significant mortality of nontarget organisms was observed outside the plots.
• The mean reduction of larvae was 49 percent (range, 34-71) for 3 plots treated at 140C, 73 percent (range, 51-87) for 3 plots treated at 180C, and 61 percent mean reduction for all plots combined.
• Reductions in numbers of larvae in plots with water velocities >8 cm/s consistently were less than reductions in plots with velocities <8 cm/s. Reductions in areas with water velocities <8 cm/s are estimated at 75 percent.

7. Bayluscide efficacy testing (lab studies)

Laboratory studies on Bayluscide efficacy were completed early in 1996 and summarized in the 1995 annual report.

8. Stock-recruitment workshop

A compensatory mechanisms workshop was held on April 10-11, 1996, in Ann Arbor, Michigan. The data presented suggests that density dependent changes in growth and mortality occur at low densities. Low spawning stocks appear to be capable of reproducing the population of parasitic lampreys.

III. Environmental Assessment

1. Public information/input

The Task Force recommends the initiation of public meetings beginning in 1997 to provide information and to gain public/agency support for the St. Marys River control initiatives.

2. Nontarget impacts

The Task Force recognizes the need to obtain more information on potential impacts on nontarget organisms, particularly when using spot applications of the granular formulation of Bayluscide. It recommends bottom trawling to assess populations of nontarget species in potential treatment zones. Assistance from other agencies is being solicited to conduct these studies in 1997.

STERILE MALE RELEASE TECHNIQUE TASK FORCE

• Task Force established April 1984
• Purpose of Task Force:
• Continue to refine the long-term strategy for the application of sterile male release in an integrated program of sea lamprey control.
• Coordinate the current large-scale research program into the effectiveness of the sterile male release technique in Lake Superior and the St. Marys River including operational and research studies to test all required hypotheses.
• Members are John Heinrich (Chair), Dennis Lavis, and Michael Twohey, U.S. Fish and Wildlife Service; Rod McDonald and Rob Young, Department of Fisheries and Oceans Canada; Gavin Christie, Great Lakes Fishery Commission Secretariat; Jim Smith (Outside Expert), Mississippi State University, Delta Research and Extension Center; Michael Hansen, Charles Bronte (Charles replaced Michael Hansen as the Lake Technical Committee representative in September) and Roger Bergstedt, U.S. Geological Survey, Biological Resources Division.
• Meetings held on March 6 and September 24-25, 1996
• Progress on charges in 1996:
• In 1995 the Commission forwarded to the Sterile Male Release Technique Task Force a list of specific charges organized in three planning groups: Strategic Long-term, Tactical/Operational, and Research. Progress on the charges is described below.

Strategic Long-term Integrated Management of Sea Lamprey (IMSL) Planning

• The first year of a 4-year study, Long-term evaluation of sterile male release for control of sea lampreys in the Great Lakes (Long-term evaluation) by Roger Bergstedt, was implemented in 8 tributaries to Lake Superior. Sterilized male (3,270), untreated male (2,896), and female (2,896) lampreys were released in 8 tributaries of Lake Superior (May 31-June 10; Table 24) according to the study protocol.
• A long-range plan of operational activities through FY2000 is detailed in Table 25.
• The Sterile Male Release Technique Task Force developed a list of sequential hypotheses (framed as questions) to describe the series of events that must occur in a successful sterile male release program. The research hypotheses addressing the long-term success of the technique are:

1. Are male sea lampreys successfully sterilized?

2. Do sterilized males reach the spawning grounds and construct nests at the expected ratio of sterilized to resident males?

3. Do sterilized males attract females to nests and mate normally?

4. Does sterility persist through mating and is percent survival of embryos at hatch reduced in individual nests?

5. Is percent survival of embryos at hatch reduced in individual streams?

6. Is the abundance of year classes of burrowed larvae (after leaving the nest) reduced in individual streams?

7. Do reductions in abundance of larvae persist through the larval life stage and result in reductions in the number of metamorphosing sea lampreys in individual streams?

8. Is the number of parasitic-phase sea lampreys in the lake reduced?

9. Is damage to fish in the lake reduced?

• Tests of hypotheses 4 and 5 were concluded and reported in the Short-term sterile male release evaluation 1995 research completion report by Roger Bergstedt.
• Tests of hypothesis 6 began with the first year of the four-year study protocol Long-term evaluation. All samples were taken according to protocol (Table 24).
• An assessment of the technique was conducted in the St. Marys River. The ratio of sterile to untreated male lampreys on nests and the viability of eggs in nests with male parents in three classes (untreated, sterile, and unobserved) were determined. Results continue to support the conclusion that sterilized males appear on nests and reduce the production of viable eggs in proportion to the ratio of sterile to untreated males in the population.
• An evaluation of the relationship between sterile male release and the other alternative controls, trapping and barriers, is in progress.
• Further modeling will be conducted in coordination with the Barrier, Assessment, and St. Marys River Control Task Forces as refined estimates of effectiveness and costs are developed. Future control strategies were modeled as a part of the research proposal Long-term evaluation.
• Forecasts of sterile-male effectiveness, levels of effort, and costs for integration into long-term suppression targets for the St. Marys River, Lake Superior, and/or other lakes are in development.

Tactical/Operational Planning

• The current effluent permit for the Lake Huron Biological Station was extended and an application for a new permit is being prepared for submission in 1997.
• Operational requirements were projected through FY 2000 in the Long-range plan of operational activities (Table 25). The plan focuses on:
• Determination of effectiveness of the current application levels in Lake Superior and the St. Marys River.
• Examination of processes and methods that add to the existing supply of male lampreys.
• The Task Force recommended operational budgets for FY 1997 and FY 1999. The Commission approved the FY 1997 operational budget.

Research Planning

• The current hierarchy of hypotheses necessary to evaluate the success of the sterile male release was reviewed and remains appropriate as stated.
• The Task Force focused on the prospect that the current research study as described in the Long-term evaluation has the potential to lead into testing of hypothesis 7.
• The current research study described in the Long-term evaluation tests the potential for density dependent responses within the following parameters: spawner run allocation, reproduction and larval recruitment, and year-class survival and growth.
• Areas in which hypotheses for evaluation studies may be developed have been identified. Research priorities remain in the two following areas and development is in progress:
• Determination of effectiveness of the current application levels in Lake Superior and the St. Marys River.
• Examination of processes and methods that add to the existing supply of male lampreys for use in the technique.
• The Task Force worked closely with Assessment, Barrier, and St. Marys River Control Task Forces to successfully conduct the Compensatory Mechanisms Workshop on April 10-11 in Ann Arbor, Michigan.
• Substantial progress is being made in internal and external research. Research recommendations through FY2000 are listed in the Long-range plan (Table 25).
• Tests were contracted in 1995 to better define the environmental fate and toxicity of bisazir as part of a review of the Lake Huron Biological Station effluent permit from the Michigan Department of Natural Resources. The following studies were completed or received in 1996: - Acute Oral Toxicity Study of Bisazir in Albino Rats (WIL Research Laboratories, Inc. 1995). The albino rat oral toxicity data (LD50 = 25.2 mg/l) indicates that bisazir is highly toxic.
• Static-Renewal Acute Toxicity of Bisazir to Daphnia magna (ABC Laboratories, Inc. 1996), and Acute Toxicity of Bisazir to Rainbow Trout (Oncorhynchus mykiss) (ABC Laboratories, Inc. 1996). Toxicity data for Daphnia magna (48-h EC50 = 70 mg/l) and rainbow trout (96-h LC50 > 100 mg/l) indicate that bisazir is only slightly toxic or nontoxic to aquatic organisms.
• Octanol/Water Partition Coefficients of Bisazir (ABC Laboratories, Inc. 1996). The partition coefficient data indicates that bisazir will not bioaccumulate or pass up the food chain.
• Hydrolysis of Bisazir as a function of pH at 25oC (ABC Laboratories, Inc. 1996). The hydrolysis study identified a list of suspected degradation products of bisazir. The Task Force recommended additional work to identify those products.
• The Task Force coordinated with John Kelso, the principal investigator of the external research project Radio-telemetry investigations of the upstream migratory behavior of sea lampreys, including sterilized males. The Task Force remains supportive of this work and recommends Dr. Kelso further examine issues related to timing of maturation of sterile and normal males in the Carp River in 1997.
• The Task Force reviewed the research proposal Effects of lamprey GnRH-I and III analogs on reproductive process and behavior of male sea lampreys. The Task Force agrees the work is relevant. Based on the correspondence, the Task Force recommends the following two issues be fully addressed prior to advancing the proposal:
• The potential benefits and cost must be defined for registration of a GnRH analog used for sterilization of male lampreys which will be released throughout the Great Lakes.
• The GnRH analog must be appropriate for stream-side administration as a sterilant to adult lampreys. The Task Force regards development of an alternate sterilant to be low priority if administration within the contained facility is required.

SEA LAMPREY BARRIER TASK FORCE

• Task Force established April 1991
• Charge is to expand the development and use of sea lamprey barriers throughout the convention area.
• Members are Dennis Lavis (chair), John Heinrich, and Ellie Koon, U.S. Fish and Wildlife Service; Tom McAuley, Department of Fisheries and Oceans, Canada; William Swink, U.S. Geological Survey, Biological Resources Division.; John Schrouder, Michigan Department of Natural Resources, Fisheries Division ; Les Weigum, U.S. Army Corps of Engineers; Dr. Dan Hayes, Department of Fisheries and Wildlife, Michigan State University; and Dr. David L. Noakes, Department of Zoology, University of Guelph.
• Meetings held on March 7 and September 25, 1996
• Progress on the charge in 1996:
• - The Basin-Wide Barrier Strategy and Implementation Plan was revised.
• - The Task Force cooperated with investigators and provided input for a research project on the effects of lowhead barriers on communities of stream fish. This project was initiated in response to a limited Request for Proposals issued in 1995 by the Task Force in coordination with the Board of Technical Experts and the Commission Secretariat.

Barrier Projects and Related Work Proposed and Accepted for FY 1997:

Lake Superior

• Furnace Creek; remedial design and repair
• Iron River; construction of lamprey barrier following removal of Orienta Dam
• Betsy River; repair and maintenance of Shelldrake Dam

Lake Michigan

• Kids (Hospital) Creek; engineering and design of barrier

Lake Huron

• Nunns Creek; modification of tribal hatchery dam

Lake Ontario

• Salmon River; removal and reconstruction of Shannonville Dam

ASSESSMENT TASK FORCE

• Task Force established April 1996
• Charges:
• - Develop strategic and long-term IMSL plans for projecting transformer production, developing summary databases, reviewing and improving key life history parameters, developing a habitat inventory, estimating efficacy of control options, evaluating the uncertainty in assessment parameters, and evaluating the role of trapping as a control strategy.
• - Create tactical and operational plans for developing cost-effective protocols for assessment, coordinating training among Agents to ensure standardization of techniques, and modifying current sampling protocols.
• - Establish internal and external research priorities, review research titles for relevance against priorities, and recommend research approaches.
• Members are Robert Young (Chair), Douglas Cuddy, and Paul Sullivan (Department of Fisheries and Oceans); Michael Fodale, John Heinrich, Katherine Mullett, and Jeffrey Slade, (U.S. Fish and Wildlife Service); Roger Bergstedt (U.S. Geological Survey, Biological Resources Division); Bill Mattes (Great Lakes Indian Fish and Wildlife Commission); and Nigel Lester (Ontario Ministry of Natural Resources).
• Meetings held on June 24 and September 23-24, 1996
• Progress on charges in 1996:
• - Developed projections of transformer production and submitted TFM treatment recommendations for the 1997 field season to the Program Integration Working Group.
• - Revised the Larval assessment sampling protocol for using the AbP-2 backpack electrofisher in Great Lakes streams.
• - Completed scheduled research on the efficiency of deep-water and back-pack electrofishers.
• - Initiated a study to help reduce the use of TFM and improve the efficiency of treatments in response to a recommendation from the Lampricide Control Task Force. The results of the study will be used to determine the benefits of maintaining lethal concentrations of TFM in the estuary by evaluating the downstream distribution of larvae.
• - Scheduled joint Service and Department training in use of the IMSL-LCSS model.
• - Developed and prioritized a list of 19 proposed research topics.
• - Established a protocol for estimating variance for Schaefer estimates of spawning runs.

LAMPRICIDE CONTROL TASK FORCE

• Task Force established December 1995
• Charges:
• - Improve the efficiency of lampricide control to maximize sea lamprey killed in individual stream and lentic area treatments while minimizing lampricide use, costs, and impacts on stream/lake ecosystems.
• - Define lampricide control options for near and long-term stream selection and target setting.
• Members are Terry Morse (Chair), Dorance Brege, David Johnson, and Dennis Lavis, U.S. Fish and Wildlife Service; Reginald Goold, Larry Schleen, and Wayne Westman, Department of Fisheries and Oceans, Canada; Mike Millar, Great Lakes Fishery Commission Secretariat; and Terry Bills and Ronald Scholefield, U.S. Geological Survey, Biological Resources Division.
• Meetings held on March 12-13, and September 12-13, 199; work session held August 21
• Progress on the charges in 1996:
• - Established and prioritized five options for saving TFM during treatments. The options will contribute toward reaching the Commission vision of a 50 percent reduction in use of TFM by the year 2000.
• - Established minimum and ideal time frames for implementing each option, and identified and prioritized research/technical assistance needs for 1996-1999.
• - Planned a combined Service and Department effort for treatment of the Rifle River in 1997 that will allow completion of the treatment in one 10-day trip and produce an estimated 4 percent reduction in use of TFM.
• - Identified six streams in which Bayluscide wettable powder can be used as an additive during treatments in 1997. This will result in an estimated five percent reduction in use of TFM.
• - Expanded LCTF membership to include a researcher, Ronald Scholefield from the Lake Huron Biological Station.

RISK ASSESSMENT

Riffle community index

Index areas of macroinvertebrate riffle communities were established in the Brule (Lake Superior) and West Branch of the Whitefish (Lake Michigan) rivers in 1985 and Sturgeon (Lake Huron) River in 1986. Sampling of macroinvertebrate populations in these areas was designed to assess long-term effects of applications of TFM. The design followed a strategy developed by the Environmental Effects of Lampricide Committee in 1983.

Samples were collected by standard traveling kick method in the spring and fall, before and after lampricide treatments in the Brule and Whitefish rivers (1986, 1989, and 1992) and in the Sturgeon River (1988 and 1994). Samples were taken upstream (control) and downstream (treated) of lamprey barriers in the Brule and Whitefish rivers. Samples were collected from a treated site in the Sturgeon River, and a control site of similar stream morphology in the Boardman River (Lake Michigan). Collection of specimens concluded in the Brule and Whitefish rivers in 1993 and in the Sturgeon and Boardman rivers in 1995.

Macroinvertebrates were identified to genera with the exception of early instars which were identified to higher taxonomic levels. The numbers of macroinvertebrates were recorded and analyzed by nested ANOVA procedure. Comparisons were conducted on total number of macroinvertebrates, number of taxa, and total number of organisms in taxa found in both control and treated sites in one or more of the streams. Comparisons were further classified by stream, year, and period of collection (spring during years of treatment, spring at least six months after treatment, and fall at least one year after treatment).

About 700,000 macroinvertebrates were collected which represented 183 taxa. A total of 670 statistical comparisons were conducted on macroinvertebrates of 127 taxa found in both control and treated index areas. The total number of organisms, number of taxa, or number of organisms within each taxa were similar or significantly greater in treated areas in 94 percent of the comparisons. The number and taxa of organisms collected varied among years and seasons but followed similar trends in treated and control sites in the rivers. The effect of applications of TFM on macroinvertebrate communities was minimal compared to the effect caused by natural environmental factors. The findings will be detailed in a project completion report.

Lake Sturgeon studies:

Protection of lake sturgeons (Acipenser fulvescens) during sea lamprey management activities is a priority. In 1982 the lake sturgeon was being considered for threatened or endangered status, and was listed in the federal Notices of Review Register as a category 2 (C2) candidate species. In 1995 the C2 classification was removed and the lake sturgeon now has no formal designation. Streams in which the safety of lake sturgeons may be a concern include the Sturgeon and Bad rivers (Lake Superior) and Peshtigo River (Lake Michigan).

A collaborative biotelemetry study of the migration of lake sturgeons and walleyes (Stizostedion vitreum) was conducted in the Bad River. The objective of the study was to determine if lake sturgeons and walleyes migrate upstream of two low gradient water falls and the Elm Hoist Road crossing, a potential site for a sea lamprey barrier. Participants included personnel from the Fishery Resources Office in Ashland, Wisconsin, U. S. Geological Survey Biological Resources Division Lake Superior Biological Station, Bad River Band of Lake Superior Chippewa Indians Natural Resources Department, Great Lakes Indian Fish and Wildlife Commission, Department of Fisheries and Oceans Canada, and Marquette Biological Station. Biotelemetry tags were attached to nine walleyes captured in gill nets in the lower river and one lake sturgeon taken upstream from Elm Hoist Road. None of the walleyes tagged and released near the stream mouth moved upstream as far as the potential barrier site. A single lake sturgeon captured and released upstream of Elm Hoist Road emigrated from the stream after release.

Personnel from Michigan Technological University in Houghton, Michigan, and Marquette Biological Station monitored the downstream movement of lake sturgeon fry in the Sturgeon River in Baraga County, Michigan, between May 29 and June 14. A total of 265 migrating lake sturgeon fry were captured and released.

Toxicity tests:

In a cooperative study, personnel from the Upper Mississippi Science Center, LaCrosse, Wisconsin, the Bad River Band of Lake Superior Chippewa Indians Natural Resources Department, and Marquette Biological Station conducted flow-through toxicity tests with TFM on juvenile and adult freshwater mussels. Atlantic elliptios (Elliptio complanata) and floaters (Anodonta cataracta) were exposed to TFM in water from the White River, a tributary of the Bad River, Ashland County, Wisconsin. The mussels along with sea lamprey larvae were exposed in each of 3 tests to a range of 9 concentrations of TFM for 12 hours.

In the 3 tests, 98.6 percent (853 of 865) of the mussels exposed to TFM survived. All mortalities occurred in concentrations of TFM greater than those used for treatment under similar water chemistry conditions (1.9 to 2.5 times the LC99.9 for sea lamprey larvae).

Behavioral responses, including valve gaping and foot extension, also were monitored. No responses which increase the exposure of the organisms to predation were observed at the LC99.9 of sea lamprey. A one-year post exposure assessment of mussels from three tests will measure latent mortality and growth among the treatment groups.

Onsite flow-through toxicity tests were conducted with whitefish (Coregonus clupeaformis) at the COFTMA fish hatchery on Nunns Creek in Mackinac County, Michigan. Whitefish were more sensitive to TFM than brown trout (Salmo trutta), but less sensitive than sea lamprey larvae in 12-hour exposures under similar water chemistry conditions. The 12-hour LC50 for brown trout (6.80 mgl-1 TFM) is about 1.7 times that of whitefish (3.95 mgl-1 TFM). The 12-hour empirical LC0.1 for whitefish (2.8 mgl-1 TFM) was about two times the 9-hour LC99.9 for sea lamprey larvae (1.5 mgl-1 TFM).

OUTREACH 1996

The Service and Department routinely are involved in outreach activities to inform the public of the benefits and operations of the sea lamprey management program. These activities range from major group participation at sports shows in metropolitan areas to the efforts of individuals in the many contacts with the media and presentations at schools. A summary of these activities for 1996 follows. (Table 26)

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