WORKSHOP TO EVALUATE SEA LAMPREY POPULATIONS "WESLP": Background Papers and Proceedings of the August 1985 Workshop edited by B. G. H. Johnson1 Citation (General): Johnson, B. G. H. (ed.). 1987. Evaluation of sea lamprey populations in the Great Lakes: Background papers and Proceedings of the August 1985 Workshop. Great Lakes Fishery Commission, Special Publication 87-2 Citation (Example for individual paper): Weise, J. G. and P.C. Rugen. 1987. Evaluation methods and population studies of larval phase sea lamprey. In B. G. H. Johnson (ed.). Evaluation of sea lamprey populations in the Great Lakes: Background papers and Proceedings of the August 1985 Workshop. Great Lakes Fishery Commission, Special Publication 87-2. 1 Address: 75 Wren Place, Kitchener, Ontario N2A lL8 WORKSHOP TO EVALUATE SEA LAMPREY POPULATIONS "WESLP": Background Papers and Proceedings of the August 1985 Workshop TABLE OF CONTENTS Page No. FOREWORD i SECTION A EVALUATION METHODS AND POPULATION STUDIES OF LARVAL PHASE SEA LAMPREY (Jerry G. Weise and Paul C. Rugen) iii - Executive Summary V - Introduction 1 - Purpose and Goals 1 - History of Techniques 2 - Current Techniques 7 - Evaluation of Sampling Techniques 9 - Summary of Larval Sea Lamprey Population Studies 14 - Life History of the Larval Sea Lamprey (Petromyzon marinus) 20 - Summary of Responses to Questionnaire 39 - Group Recommendations 41 - Proposal No. A-l - Use of the Removal Method to Estimate Populations of Sea Lamprey Larvae and-Transformers 43 - Proposal No. A-2 - Efficiency of Control Agent Evaluations of Sea Lamprey Ammocoete Populations 59 - Proposal No. A-3 - To Estimate Transformer Production from Larval Sea Lamprey Populations in Streams Tributary to a Lake Basin, Lake Superior Used as an Example 61 - Proposal No. A-4 - To Estimate Sea Lamprey Production (Larval, Trans- former, Parasitic and Adult) in a Lake Basin and Evaluate the Relationship of One Life Phase to the Others 69 - Appendix A-I - Criteria for the Selection of Streams for Stream Treatment with Lampricides 71 SECTION B SUMMARY OF EVALUATION METHODS AND POPULATION STUDIES OF PARASITIC PHASE i SEA LAMPREY (F. W. H. Beamish and Lee H. Hanson) . - Executive Summary 2.22 - Introduction 1 - Purpose and Goals 1 - Past and Present Practices of Assessing the Parasitic Phase Population 2 - Biology of Parasitic Phase Sea Lamprey - A Review of Information Pertinent to the Evaluation of Sea Lamprey Populations 24 - The Questionnaire 27 - Recommendations for Additional Studies 33 - Proposal No. B-1A - Use of Commercial Large-Mesh Trap Nets to Determine Abundance of Parasitic Sea Lampreys 35 - Proposal No. B-1B - Abundance of Parasitic Phase Sea Lampreys as Deter- mined by Lampreys Collected from Sport Fishermen 40 - Proposal No. B-1C - Estimation of Relative Abundance of Parasitic Phase -Sea Lamprey from Lake Trout Assessment Data 44 Page No. - Proposal No. B-2 - Mark and Recapture Study for Population Estimates of Parasitic Phase Sea Lampreys 46 - Proposal NO. B-3 - The Use of Sea Lamprey Statolith Composition to Determine Stream of Origin 53 - Proposal No. B-4 - Examination of Lampricide Treatments and Subsequent Effects on Lamprey Wounding of Lake Trout for Determination of Origins and Movements of Parasitic Phase Sea Lampreys 54 - Proposal No. B-5 - Assessment of Lake Trout Carcasses in Lake Ontario 56 - Appendix B-I 58 - Appendix B-II 59 - Appendix B-III 60 - Appendix B-IV ,6 1 SECTION C SUMMARY OF EVALUATION METHODS AN-D POPULATION STUDIES OF SPAWNING PHASE SEA LAMPREY (Harold A. Purvis and Rodney B. McDonald) i - Executive Summary iii - Introduction 1 - Purpose and Goals 2 - Past and Present Practices of Spawning Phase Assessment 2 - Pertinent Spawning Phase Life History Information 18 - The Questionnaire 30 - Additional Studies and Informational Needs 38 - Detailed Description of Proposals 40 - Proposal C-l - Relative Abundance Based on Counts from Index Streams 41 - Proposal C-2 - Relative Abundance Based on Changes in Biological Characteristics 44 - Proposal C-3 - Absolute Population Estimates Based on the Mass Release of Marked Spawners into the Lake Environment 48 -- Proposal C-4 - Lakewide Expansion of Absolute Population Estimates from Index Streams 52 SECTION D PROCEEDINGS OF THE WORKSHOP TO EVALUATE SEA LAMPREY POPULATIONS (WESLP) IN THE GREAT LAKES, AUGUST 1985 (John W. Heinrich, James G. Seelye and B. G. Herbert Johnson) i - Introduction 1 - Spawning Phase Group 4 - Parasitic Phase Group 6 - Larval Phase Group 9 - Lake Superior Group 12 - Lake Michigan Group 13 - Lake Huron Group 15 - Lake Erie Group 17 - Lake Ontario Group 18 - Overview 20 - Appendix D-I - Workshop Organization and Attendance 28 - Appendix D-II - Results of the Three Polls in which Participants Voted on the Priority of the Assessment Proposals 29 SECTION E REFERENCES AND ACKNOWLEDGEMENT OF THE WORKSHOP TO EVALUATE SEA LAMPREY POPULATIONS (WESLP) IN THE GREAT LAKES, AUGUST 1985 - References 1 -'Acknowledgements 18 i FOREWORD The Workshop to Evaluate Sea Lamprey Populations (WESLP) originated among the biologists in the sea lamprey control units of the Great Lakes Fishery Commission (GLFC), who saw a need to review the methods used to evaluate sea lamprey populations, particularly as to their abilities to provide measures of the accuracy and reproducibility, over space and time, of estimates of sea lamprey abundance. Such perceptions had been intensified and focused by suggestions developed in other contexts such as the Sea Lamprey International Symposium (SLIS), the Sea Lamprey Audit Team (SLAT), the Workshop Concerning the Implementation' of Integrated Pest Management (IPM), and the Application of Decision Analysis to Sea Lamprey Control. The proposal for implementing WESLP was presented to the GLFC in 1983 by the Committee for the Review of Commonality in Sea Lamprey Control (a group of investigators appointed from the GLFC's two control units). The objectives of WESLP were to review past and present methods and practices used to assess sea lamprey populations in the larval, parasitic and spawning life stages; to investigate the needs to expand or improve current assessment strategies; and to recommend alternate ways to collect, interpret and present the data. Following the GLFC's decision to sponsor WESLP, a formal structure was developed for the Workshop. A Steering Committee was struck for the purpose of establishing an agenda, while three sub-groups were formed -- one for each of the sea lamprey's life stages -- for the purpose of preparing background papers on the currently status of sea lamprey evaluation methods used by the control units. Other fishery investigators and managers arOli.rld the Great Lakes were invited to participate in WESLP through correspondence E The final plenary session of WESLP took place In Aug11.s t ) 1985) at Marquette, Michigan. This publication contains the three "Life Stage" reports prepared by the sub-groups, a summary of the recommendations and workshop proceedings prepared by the Steering Committee, and lists of the workshop's organization and attendance. It is hoped that these documents will serve to describe the present methods of sea lamprey population evaluation; to record the needs expressed for the improvement of such methods; and to present the suggestions made for obtaining better measures of sea lamprey numbers. B. G. H. Johnson Editor iii SECTION A EVALUATION METHODS AND POPULATION STUDIES OF LARVAL PHASE SEA LAMPREY by Jerry G. Weise Canada Department of Fisheries and Oceans Sea Lamprey Control Centre Sault Ste. Marie, Ontario and Paul C. Rugen United States Fish and Wildlife Service Marquette Biological Station Marquette, Michigan V This report dealing with the larval/transformer phase of the sea lamprey (Petromyzon marinus) is one of three “life stage” reports prepared for the Workshop for Evaluating Sea Lamprey Populations (WESLP) sponsored by the Great Lakes Fishery Commission (GLFC). The purpose is to develop improved methods for estimating larval sea lamprey populations in the Great Lakes and for reporting this information in a consistent format to the GLFC and its associated agencies. the goal of the workshop is to review present methods of evaluating sea lamprey populations, to identify needs for more or better information and to propose ways of satisfying these needs. The history of the techniques used to sample larval/transformed sea lamprey is described from the sifting of stream habitat with shovels, through applications of toxicants, to the use of electrical (portable and backpack) shocking equipment. Over the past 33 years special traps have been designed to capture downstream migrant lampreys, and various marking techniques have been developed or modified for Lamprey population studies. Larval lamprey population studies began in earnest when the different species of lamprey could be identified. The age of Larval lamprey can be reasonably predicted by reviewing length-frequency data but definitive u&-g techniques for larvae older than three years or transfomning individuals have not proven reliable. Current studies are underway to develop an accurate aging technique. The life history of the larval sea lamprey is stanarized from the fecundity of adult sea lamvre,~, -through egg deposition and survival of embryos to duration of Larval life inCaZt&ing qrowth rates, until transformation ends this stqfr! and migration takes the ,~arasi~t<c sea lamprey into the ‘Lakes. Larval lamprey .;iabi tat preference and within stream movement-by larvae and transformers are described. Both agents of