F-81-R-2, Study 460 - 1

F-81-R-2, MichiganAmended

Study 4602000-01

460.Name of Study:Dynamics of the Lake Erie walleye and yellow perch populations and fisheries

A.Problem: Walleye and yellow perch are the most valuable fishery resources in the lower Great Lakes, where they contribute substantially to harvests in Michigan (sport), Ohio (sport), and Ontario (commercial and sport). These species have shown wide fluctuations in reproductive success, which strongly influences their adult density, growth, mortality, predation rate on forage base and so forth. It is known that the same walleye move extensively throughout the different jurisdictions where they are subject to fishery harvest. There are interagency agreements, through the Great Lakes Fishery Commission (GLFC), to conduct annual population surveys of Lake Erie walleye and yellow perch stocks. These yearly samples are critical to the production of the data pool and statistics necessary to model population dynamics, and to eventually determine harvest quotas. Survey data are shared and analyzed through the various working groups of the GLFC's Lake Erie Committee (see annual reports since 1978).

B.Objective: To develop and verify models for interagency quotas of walleye and yellow perch in Lake Erie with Ohio, Pennsylvania, New York, and Ontario from population samples taken each spring and fall.

C.Justification: Walleye and yellow perch have supported extremely valuable sport and commercial fisheries in the Lake Erie waters of Ontario, Ohio, Pennsylvania, New York, and Michigan. Preliminary walleye harvest estimates since 1988 indicate that an average of 6.5 million fish have been caught each year. While separate walleye stocks are probably involved, tagging and genetic studies have shown that they all move extensively throughout the interagency management area. Successful management depends upon consistent annual assessment of population structure and harvest, as well as finding adequate age-structured modeling techniques for predicting future standing stocks and desirable harvest rates. Annual sampling has been conducted by the five agencies since 1978 (see Ohio DJ, F-35-R-26; Pennsylvania DJ, F-62-R) and results pooled to establish long-term data sets for modeling. Considerable fluctuation in reproductive success and population abundance has been observed, particularly for yellow perch. At present, there is little known about the effects of environmental variation on walleye and yellow perch reproductive success, and, therefore, no suitable means exists to predict future year class strength from broodstock estimates. Annual surveys of young-of-year and yearlings are needed by each agency to produce estimates for their recruitment into catchable stocks at ages 2 and 3. Recruitment estimates will be combined with model predictions of adult stocks to set quotas. All survey data and analyses will be shared with other fisheries management agencies to meet interagency commitments.

D.Status: Jobs 1 through 8 have been completed as stated in the 1994-95 amendment. Job 9 has been fulfilled by completion of a five-year interim report which presents a more in-depth analysis of the data and findings from Lake Erie surveys during the period from 1994 through 1999. In addition, a number of studies have been published on various aspects of Lake Erie walleye and yellow perch biology and management (Nepszy 1977, Busch et al. 1975, Parsons 1970, Wolfert 1963, Knight et al. 1984, Shuter and Koonce 1977, Shuter et al. 1979). Survey data from Michigan, Ohio, Pennsylvania, New York, and Ontario have been reported annually by the GLFC's Lake Erie Committee. However, no methodology nor published data are available for adequately predicting future recruitment and harvest. Therefore, walleye and yellow perch population dynamics (growth, mortality, exploitation) must be monitored annually to provide parameters required as model inputs and information for evaluation of management actions and validation of predictions from population models.

This study is being amended in 2000-01 to extend the study one additional year. This will allow for the Michigan Department of Natural Resources, Fisheries Division's editing and finishing process.

Literature Cited:

Brownie, C., D. R. Anderson, K. P. Burnham, and D. s. Robson. 1985. Statistical inference from band recovery data--A handbook (2nd edition). U.S. Department of the Interior, Fish and Wildlife Service, Resource Publication No. 156, Washington, D.C.

Busch, W. D. N., R. L. Scholl, and W. L. Hartman. 1975. Environmental factors affecting the strength of walleye year classes in western Lake Erie, 1969-1970. Journal of the Fisheries Research Board of Canada 34:1039-1041.

Knight, R. L., F. J. Margraf, and R. F. Carline. 1984. Piscivery by walleyes and yellow perch in western Lake Erie. Transactions of the American Fisheries Society 113:677-693.

Nepszy, S. J. 1977. Change in percid populations and species interactions in Lake Erie. Journal of the Fisheries Research Board of Canada 34:1861-1868.

Parsons, J. W. 1970. Walleye fishery of Lake Erie in 1943-62 with emphasis on contributions of the 1942-61 year classes. Journal of the Fisheries Research Board of Canada 27:1475-1489.

Shuter, B. J. and J. F. Koonce. 1977. A dynamic model of the Western Lake Erie walleye (Stizostedion vitreum vitreum) population. Journal of the Fisheries Research Board of Canada 34:1972-1982.

Shuter, B. J., J. F. Koonce, and H. A. Regier 1979. Modeling the western Lake Erie walleye population: a feasibility study. Great Lakes Fisheries Commission, Technical Report No. 32, 40 pp.

Wolfert, D. R. 1963. The movement of walleyes tagged as yearlings in Lake Erie. Transactions of the American Fisheries Society 92:414-420.

E.Procedure: These Lake Erie walleye and yellow perch index studies will provide data on age structure, growth rates, mortality rates, exploitation rates and recruitment of yearling and older fish into the catchable population. These are a continuation of annual surveys that have been carried out by the Michigan Department of Natural Resources since 1978. They will be augmented by a Lake Erie creel survey (Michigan F-53-R, Study 427) which will provide estimates of angler effort and catch by age group.

Job 1.Set survey trap nets in Lake Erie, off Monroe, during April and May to capture walleye, yellow perch, and other species. Collect age and growth data from walleye, yellow perch, and associated species. Tag walleye as part of interagency program to estimate stock interactions and rates of exploitation and natural mortality.

Job 2.Analyze yellow perch and walleye age and growth data collected during spring trap-net sampling. Provide data files and summaries to cooperating agencies involved in Lake Erie management.

Job 3.Collect walleye tag recovery data from cooperating sport and commercial fishermen and provide individual responses with tagging information.

Job 4.Summarize walleye tag recovery data and analyze with the ESTIMATE computer model (Brownie et al. 1985) to produce year specific estimates of mortality and exploitation. Combine all tag data from cooperating agencies to estimate exploitation and natural mortality to improve and validate quota modeling.

Job 5.Carry out fall gill-net sampling at two stations to develop an index to abundance of yearling walleye. Collect age and growth data on all age groups of walleye and other species.

Job 6.Analyze age and growth data collected during fall gill-net sampling. Combine all data from cooperating agencies to estimate recruitment into adult population.

Job 7.Participate in the Scientific Technical Committee, and the Walleye, Yellow Perch, Interagency Trawl Indexing, Interagency Indexing, Statistics and Modeling, and Forage Task Groups whose goal is to model the walleye and yellow perch populations, and ultimately the entire fish community. Prepare quota estimates for common fish stocks.

Job 8.Prepare performance report and annual report for meeting of the Lake Erie Committee of the Great Lakes Fisheries Commission.

Job 9.Complete analyses of long-term recruitment, growth, and mortality data. Prepare five year interim report comparing walleye and yellow perch populations over longer time interval than covered under annual performance reports.

Job 10.Publish report through the Fisheries Division's editing and finishing process for Research and Technical reports.

F. Schedule:

YearWork planned

1999-00Job 1.Carry out trap-net sampling.

Job 2.Analyze growth data from traps.

Job 3.Collect tag recovery data.

Job 4.Analyze tag recovery data.

Job 5.Carry out gill-net sampling.

Job 6.Analyze growth data from gill nets.

Job 7.Participate in interagency work groups.

Job 8.Prepare annual reports.

2000-01Job 1.Carry out trap-net sampling.

Job 2.Analyze growth data from traps.

Job 3.Collect tag recovery data.

Job 4.Analyze tag recovery data.

Job 5.Carry out gill-net sampling.

Job 6.Analyze growth data from gill nets.

Job 7.Participate in interagency work groups.

Job 8.Prepare annual reports.

2001-02Job 1.Carry out trap-net sampling.

Job 2.Analyze growth data from traps.

Job 3.Collect tag recovery data.

Job 4.Analyze tag recovery data.

Job 5.Carry out gill-net sampling.

Job 6.Analyze growth data from gill nets.

Job 7.Participate in interagency work groups.

Job 8.Prepare annual reports.

2002-03Job 1.Carry out trap-net sampling.

Job 2.Analyze growth data from traps.

Job 3.Collect tag recovery data.

Job 4.Analyze tag recovery data.

Job 5.Carry out gill-net sampling.

Job 6.Analyze growth data from gill nets.

Job 7.Participate in interagency work groups.

Job 8.Prepare annual reports.

2003-04Job 1.Carry out trap-net sampling.

Job 2.Analyze growth data from traps.

Job 3.Collect tag recovery data.

Job 4.Analyze tag recovery data.

Job 5.Carry out gill-net sampling.

Job 6.Analyze growth data from gill nets.

Job 7.Participate in interagency work groups.

Job 8.Prepare annual reports.

Job 9.Prepare five-year interim report.

2004-05Job 10.Publish report.

G.Geographical Location: Lake Erie study location for the spring trap-net survey is approximately 2 miles east of Monroe, Michigan and 1-3 miles south of the mouth of the Raisin River. Fall gill-net stations are located 2 miles east of Stoney Point and 1 mile east of Woodtick Peninsula. The data analyses and report writing will be performed at the Lake St. Clair Fisheries Research Station in Mt. Clemens, a facility of the Michigan Department of Natural Resources.

H.Personnel: Michael V. Thomas, Fisheries Research Biologist; Robert C. Haas, Biologist In Charge, Mt. Clemens Fisheries Research Station; Staff of the Mt. Clemens Fisheries Research Station; Research Administrative personnel, and contract editor.