A Study of the Fishes Caught by Anglers in Downtown Madison, Wisconsin.

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A STUDY OF THE FISHES CAUGHT BY ANGLERS IN DOWNTOWN MADISON, WISCONSIN

By Laura Gintz

University of Wisconsin – Madison

INTRODUCTION

This paper is concerned with information about the sport fishery in Madison, Wisconsin.  It looks at what anglers are catching, how much they are catching, the area and depth where they are fishing, and how they are fishing.  The data was collected from anglers on downtown Madison lakes by University students to get information about some of the common fish species on the lakes.  The species examined included bluegill (Lepomis macrochirus), black crappie (Pomoxis nigromaculatus), white crappie (Pomoxis annularis), perch (Perca flavescens), walleye (Stizostedion vitreum), largemouth bass (Micropterus salmoides), and northern pike (Esox lucius).  The data was then used to compare species composition, size and age distributions, catch rates and habitat of Madison lakes fishes sampled by the winter anglers.

METHODS

All data was collected on February 7, 2004.  Groups of two to three University of Wisconsin – Madison students in the Ecology of Fishes class went out onto one of four lakes in Madison, Wisconsin to get information from anglers.  Half of the students went out onto the lakes at 8:30 a.m. and the other half went out at 12:30 p.m.  The four lakes studied were Lake Mendota, Lake Wingra, Monona Bay, and Mud Lake.  The locations looked at on Lake Mendota were Lake Street, Picnic Point, the shoreline, southwest Mendota, and University Bay.

Each group interviewed five anglers and filled out a data sheet for each angler.  A total of 128 anglers were interviewed, however the data for one of the anglers was removed from the data set because they were fishing for zero hours.  The data collected from each angler was the following:  time spent fishing, total lengths of all fishes caught recorded by species, type of gear, type of bait, number of lines, water depth, and depth of line.  Scale samples were then requested from the angler for all fishes caught, so that the age of the specimens could be determined.  Scales were placed in small envelopes that were labeled with the fish species, fish length, date, and an identification number.  The angler was also asked if the fishes could be cut open to determine their sex.  If the angler allowed, then the sex was determined by opening up the visceral cavity of the fish and looking at its gonads.  It was considered a male if there were white testes and female if there were yellow, granular ovaries (because they were full of immature eggs).  Other data recorded on the data sheets were the time, air temperature, percent cloud cover, wind speed, wind direction, visibility, depth of ice, and the number of anglers in the area.

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After data was collected from five anglers, the groups went back to the laboratory to examine the scale samples collected from the fishes.  The scales were mounted between glass slides and looked at under projectors and microscopes to determine the fishes’ ages.  This was done by looking at the groups of concentric rings (circuli) on scales that were classified into annuli and interpreted as seasonal growth marks.  The location of an annulus was determined by the presence of a crossing-over between the circuli found on the scale.  The crossing-over was identified by the first continuous circulus of the new growth ...

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