Publications

Federal, provincial, state, and university organizations participated in cooperative limnological surveys of Lake Erie in September 1959 and August 1960 to determine the extent and severity of the low dissolved-oxygen content of the hypolimnetic waters. Observations were restricted to the central basin in 1959, but were lake-wide in 1960. Approximately 70 percent of the bottom waters of the cent

A total of 3,998 yearling walleyes, Stizostedion vitreum vitreum (Mitchill), were captured, tagged, and released along the south shore of western Lake Erie to determine their movements and their dispersal from a known nursery area. Four hundred ninety-nine recoveries were made over a period of 3 years. Tagged walleyes traveled primarily north toward the islands in the Western Basin during their fi

Stomachs were examined from 1,469 Lake Michigan bloaters, Coregonus [Leucichthys] hoyi, greater than 7 inches long which contained identifiable food. An additional 461 ciscoes less than 7 inches long were incorporated into the study; these latter fish were not positively identified, but most of them undoubtedly were bloaters. The specimens were caught in bottom nets except for 49, all less than 6

This laboratory located about 40 miles west of Detroit, near the intersection of highways I-94 and US-23, can be reached by bus, railroad, or via commercial airlines to Detroit Willow Run or Metropolitan airports. Field biological stations are located in Wisconsin at Ashland; in Ohio at Sandusky; and in Michigan at Ludington, Marquette, Millersburg, and Northville.

The average annual commercial production of whitefish in the U.S. waters of Lake Superior dropped from 2,194,000 pounds in 1879-1908 to 504,000 pounds in 1911-59. The modern production, though far below the earlier, has accounted for more than 10 percent of the total value of the fishery in all but one of the last 20 years. Data are given on growth rate, age and year-class composition, size distr

The trout-perch, Percopsis omiscomaycus (Walbaum), is one of the more abundant forage fishes in the larger lakes of midwestern United States and central Canada where walleye, Stizostedion v. vitreum (Mitchill), yellow perch, Perca flavescens (Mitchill), and coregonids predominate. It has been suggested that it may have considerable effect on perch and walleye populations of these lakes. The pres

The round whitefish has been of some commercial importance in the upper Great Lakes but production in Lake Superior has generally been small; the United States average was 26,600 pounds for 1929-59. This study is based on 1,173 fish collected in the Apostle Islands in 1958-60 and 103 collected at Isle Royale in 1958 and 1960. The average age of 6.0 years at Isle Royale was concluded to be signific

Seven hundred fourty-five bottles containing post cards for recording of information were released at stations in Lake Michigan; 283 were released June 17 to August 17, 1931, south of a line from Frankfort, Michigan, to Algoma, Wisconsin, and 462 during May 9 to August 25, 1932, both south and north of that line. One hundred eighty-six bottles or 65.7 percent of those released in 1931, 331 bottle

Marking experiments on three streams in the Upper Peninsula of Michigan yielded quantitative estimates of populations of larval and transforming lampreys. The estimates not only gave an idea as to the numbers of ammocetes in the streams, but also confirmed the judgments of abundance based on earlier surveys with electric-shocking equipment and provided valuable information on the movement of larva

No abstract available.

A dye detector, based on a modified photoelectric amplifier, has been planned, built, and tested. It was designed to record automatically the time of arrival of fluorescein dye at predetermined points in a stream system. Laboratory tests and stream trials proved the instrument to be efficient. Small changes in color can be detected in turbid or clear water. The unit has been used successfully for

Electrical conductivity has been widely used in freshwater research but usual methods employed by limnologists for converting measurements to conductance at a given temperature have not given uniformly accurate results. The temperature coefficient used to adjust conductivity of natural waters to a given temperature varies depending on the kinds and concentrations of electrolytes, the temperature