Michigan's Great Lakes sport fishery has been monitored with a statewide contact creel survey program since 1983. The objective of the program is to obtain a continuous record of sport catch, catch rates, and catch composition for the Great Lakes and important anadromous river fisheries.

A fundamental requirement for sound management of the Great Lakes fisheries is knowledge of the response of fish stocks to fishing and the contributions of various fish stocks to the fisheries. Success and future value of the Great Lakes and anadromous stream fisheries depends on long-term consequences of current management. It is essential that management decisions be based on a sound empirical knowledge of the history, current status, and dynamics of fish communities. Fishing statistics are needed for stock assessment and to facilitate stock identification. Coupled with fish marking studies, these kinds of data can identify Great Lakes and anadromous fish stocks and determine their distribution, movements, and contribution to various sport fisheries. Data collected from this program have been used to develop, test, and improve decision models which help discern management strategies for Great Lakes fish communities and fisheries. For example, the catch and effort estimates for yellow perch and walleye from Lake Erie are an important component of interagency harvest quota calculations. The Michigan data are used jointly with creel estimates from Ontario, Canada, New York, and Ohio on an annual basis in an effort to prevent over-harvest of these two important species.

Creel Survey Methods

Michigan Department of Natural Resources (MDNR) Fisheries Division personnel interview from 50,000 to 75,000 anglers annually. Approximately three-quarters of these anglers are contacted during the April through December open-water season; the remainder are interviewed during the winter ice fishing season (January through March). Interviews are conducted on all of the Great Lakes - on Lake Michigan from New Buffalo to Harbor Springs and from Menominee to the Bays de Noc; on Lake Huron from Lexington to Rogers City; on Lake Erie from Point Mouillee to the Michigan-Ohio state line; and on Lake Superior from Black River Harbor to Munising Bay. The major winter ice fisheries sampled are at Menominee / Little Bay de Noc, Saginaw Bay, Keweenaw Bay, Marquette, and Munising Bay.

Also, prior to 1 August 1989, the charter boat mode of fishing was included as part of this study. As a result of legislation in Michigan during 1989, charter boat operators are now required to report their clients catch and angling effort monthly to MDNR (Charter Reporting Program). After 1989, charter boats were no longer covered by this study. However, in order to make valid year-to-year comparisons, catch and effort reported by charter fishermen are sometimes added to the catch and effort estimates generated by this study.

The creel survey used in Michigan is based on a stratified design, using simple random sampling within strata. Strata include port fished by month, by weekday-weekend (holiday), and by mode of fishing. Catch and effort estimates are made for each stratum and then combined to give monthly and seasonal figures. Each work schedule is specifically tailored for the area being sampled. Both weekend days and three randomly selected weekdays are sampled each week. The entire angling day from dawn to 1 hour past dusk is covered.

Two types of data are collected for each area sampled: angler party interviews for catch rates and angler (or boat) counts for effort. An angler party is defined as one or more anglers who fished together. Angler parties are interviewed at the completion of their fishing trips at various boat launching ramps, marinas, piers, and along the shoreline. Anglers are queried as to their mode of fishing (i.e., boat, shore, pier, open ice, or shanty ice), where they fished, how long they fished, what they fished for, the numbers (by species) of fish they kept, and the number of fishing trips they made or intended to make that day. Additional data are collected on each angler in the party such as age and sex, zip code or county of residence, and the types of angling method used (casting, still fishing, trolling, etc.). These data are recorded on an angler interview form by census personnel. Biological data is also collected from any fish that the anglers captured during the trip.

Fishing effort is determined through instantaneous and interval counts of anglers or boats in a given area. Instantaneous counts are used when all boats or anglers in a sample area can be observed from a given point at one time. Interval counts are used when the sample area is too large to be observed from one point. In this case, the number of boats or anglers passing the observation point during a 30-minute period is used to determine the number of fishermen in the entire sampling area. All counts of boat trailers, pier anglers, shore anglers, open-ice anglers, and ice shanties are instantaneous. However, both instantaneous and interval boat counts are made depending on the sampling area. The type and number of boating access points within the sample area determines the type of boat count used. Interval counts are used in cases where boat access to the open lake is limited to harbor areas where all boats exit through defined channels. Most fishing effort counts are made from the ground by creel clerks at randomly selected times. Instantaneous counts made from 3 airplanes of boats, pier, and shore anglers are used only when ground counts are not feasible, such as areas with many access points or restricted visibility. Air flights are used to make fishing effort counts on Saginaw Bay and Lake Erie. Five flights are made each week at randomly selected starting times--one each weekend day, and one on each of three randomly selected week days. All effort counts, whether accomplished from the ground or air, are recorded on count data forms by census clerks or contract pilots.

Creel Survey Analyses and Results

Catch and effort estimates are made for each port or fishing area by month. Standard mathematical formulas for creel census (Ryckman 1981) are used to calculate all estimates. Three measures of fishing effort are calculated: angler hours, angler trips, and angler days. An angler trip is one completed fishing excursion. An angler day is composed of one or more fishing excursions during a 24- hour period. Error bounds for all catch and effort estimates are calculated as two standard errors of the mean (2 times the square root of the variance, divided by the number of observations for an estimate) and approximate true 70-95% confidence limits, depending on sample size.

Comparisons of results over the entire data series (1985-94) have been made difficult due to constrained budgets during 1989-91. During those years, sampling at a number of ports and fishing areas was discontinued. Since 1992, most of these ports and areas have been added back into the annual sampling scheduled. To follow trends in the fishery for salmonines and make year to year comparisons on lakes Michigan and Huron, "index ports" were selected based on their importance to the lake-wide salmonid harvest during years when all Michigan ports were sampled and their consistency of being sampled each year. Creel Survey data is reported by port, as well as for these index ports and for each Great Lake, combined.

Link to result tables and reports - FUTURE