David S. Shetter

Observations on Movements of Wild Trout in Two Michigan Stream Drainages

Abstract This report deals with the migration of wild brook trout and brown trout, over 7 inches long, in Hunt Creek and the upper Au Sable River system. Between 1934 and 1967 we jaw-tagged 3,320 brook trout and 5,615 brown trout; anglers recaptured and reported 346 of the brook trout and 480 brown trout. Brook trout were recaptured close to where they had been tagged and released--88% within 1 mile, the remainder within 11 miles. Migration of brown trout (in the Au Sable system) was more variable. Seven- to 13-inch brown trout remained (56–85%) within 1 mile of tagging sites. Many browns over 13 inches in the North and South Branches Au Sable migrated several miles (some up to 10 to 40 miles), but in the Main Au Sable 90% of the big browns were less than 1 mile from tagging site. Spring-tagged trout produced twice as many returns as did fall-tagged fish. Brook trout recoveries were 97% within the first year after tagging; 67% of the browns came within the first year; the other 33%, in 2 to 5 years.

The Effects of Deflectors in a Section of a Michigan Trout Stream

Abstract The changes in angling produced by current deflectors in a 1,605-foot section of Hunt Creek, a Michigan brook trout (Salvelinus fontinalis) stream, were studied over an 8-year period, 3 years before and 5 years after placement of the devices. Data on changes in the physical character of the stream, the fish population, and the bottom food supply also are presented for 1 year before and 3 years after installation of deflectors. The methods used to measure these various changes are given. Installation of 24 pool-forming deflectors raised the number of good pools from 9 to 29, increased the average pool depth by 6 inches, and exposed additional gravel without significantly changing the average stream depth over the entire section. Preliminary and unpublished bottom-food studies indicated a decrease in total number and volume of all organisms but an increase in forms found most frequently in trout stomachs. Fish-population studies demonstrated slight increases in the number of smaller trout present a...

Species Composition by Age Groups and Stability of Fish Populations in Sections of Three Michigan Trout Streams during the Summer of 1937

Abstract Intensive studies of the fish populations in three sections of the South Branch of the Pine River, two sections of the Little Manistee River, and three sections of the North Branch of the Boardman River were carried out monthly from June to September, 1937. The same sections were blocked and seined each month and the fish found there were enumerated by species, weighed, and measured. Scale samples were collected from all trout above age-group O. The efficiency of the block-and-seining method of stream census was tested in the most difficult section to seine (lower census section on the South Branch of the Pine River). It was found to be 89.1 per cent effective, comparing favorably with results of similar tests conducted in New Hampshire trout streams. As far as could be determined, the method was 100 per cent efficient for the enumeration of the trout population. Only the very small minnows, muddlers, and suckers escaped the first seining. From the results of the seinings and from plane-table map...

A Brief History of the Sea Lamprey Problem in Michigan Waters

Abstract The life history of the sea lamprey is briefly outlined. Mature adults are anadromous, spawning chiefly in May and June and dying shortly thereafter. The larvae pass 4 to 5 years in the sand, gravel, and silt banks of the spawning stream before transforming into the parasitic stage. After becoming fitted for a parasitic life, they live as free-swimming adults, parasitic on fish, from 1 1/2 to 3 1/2 years before becoming sexually mature and ready to spawn and die. The sea lamprey spread into the upper Great Lakes within the period 1921–1936, and is firmly established in Lakes Erie, Huron, Michigan, and Superior, and possibly in some of the larger inland lakes. Experiments of 1944 and 1945 on the Ocqueoc River in northeastern Michigan involving the operation of a sea lamprey trap were described. Although the trap failed to take a portion of the run each year, 3,366 lampreys were destroyed in 1944 and 4,608 lampreys were caught and killed, in 1945. Most of the upstream movement (95 percent or more) ...

Further Results from Spring and Fall Plantings of Legal-Sized, Hatchery-Reared Trout in Streams and Lakes of Michigan

Abstract Further tagging experiments in Michigan with spring and fall plantings of brook trout (Salvelinus f. fontinalis, brown trout (Salmo trutta), and rainbow trout (Salmo gairdnerii irideus) from which recoveries were made during the 1942 trout season confirmed the conclusion that spring release of adult or near adult hatchery-reared brook trout and rainbow trout is more desirable than the fall planting of fish of a similar size. In some instances fall stocking of brown trout may furnish as good fishing in the following seasons as does spring planting. Recoveries of planted fish past the first season of availability ranged from 0.0 to 2.5 per cent in the second season and from 0.0 to 0.5 per cent in the third season. In either spring or fall planting of legal-sized fish, no advantage was gained by scattering the fish widely over the stream areas stocked. Eighty five per cent or more of the planted trout recovered were caught within 10 miles of the point of release, regardless of the season or method o...

The Effect of Fin Removal on Fingerling Lake Trout (Cristivomer Namaycush)

Abstract Four lots of fish marked by fin removal were held at the State fish hatchery, Marquette, Michigan, to ascertain the amount of fin regeneration, comparative survival, and comparative growth which would follow this treatment over varying periods of time. It was determined that the following percentages of the surviving marked fish should be recognizable (regeneration 0–50 percent of the fin area) in the future: 1944 mark, dorsal and adipose fins clipped, 90.4 percent; 1945 mark, right pectoral fin clipped, 96.5 percent; 1946 mark, left pectoral fin clipped, 89.8 percent; 1947 mark, right pelvic fin clipped, 64.1 percent. Observations of fin regeneration suggested further that the calculated numbers of marked fish surviving in the mortality-growth experiments conducted at the same time should be adjusted upward, as it was demonstrated that from 0.2 to 20.8 percent of the survivors of the regeneration experiments had fully regenerated fins when examined at various times during the course of the exper...

Effects of Jaw Tags and Fin Excision upon the Growth, Survival, and Exploitation of Hatchery Rainbow Trout Fingerlings in Michigan

Abstract Approximately equal numbers (995 to 1,000) of jaw-tagged, fin-clipped, and unmarked rainbow trout fingerlings were planted in experimental sections of Hunt Creek in October, 1952. Observations on these fish during 1952–1957 provided data on the effects of marking on growth, survival, and angler exploitation. Jaw-tagged fish grew more slowly than did either the fin-clipped or unmarked fish; differences in growth increments were between 0.53 and 0.47 inch over an 11-month period. There was little difference in growth between fin-clipped and unmarked fish. Relatively few rainbow trout attempted to migrate, and no difference in extent of attempted migration was detected between marked and unmarked fish. There was no significant difference in angler exploitation rates among the three groups of fish in any one year, but the 5-year totals for the three groups showed highly significant differences. Tagged, fin-clipped, and normal rainbow trout were caught in increasing numbers, in that order. More tagged...

Results from Plantings of Marked Trout of Legal Size in Streams and Lakes of Michigan

Abstract Intensive creel censuses served as the chief basis for estimates of the effectiveness of plantings of marked legal-sized brook trout, brown trout and rainbow trout at various seasons over a period of from 1 to 3 years in sections of five public streams and in two private streams. Similar data are presented for plantings of rainbow trout in five lakes. Returns from fall planting in streams never exceeded 5.3 per cent; spring and open-season plantings resulted in the recovery by anglers of from 4.9 to 61.9 per cent of the fish released. Fall plantings of rainbow trout in lakes yielded returns up to 66 per cent. Plantings of from 100 to 160 trout per mile of stream averaging 50 feet in width yielded higher percentage returns than did plantings of larger numbers of fish, benefited relatively more anglers, and did not stimulate the catch of native fish. The increase in the catch per hour and the percentage of hatchery fish in the total catch appeared to be inversely proportional to the density of the ...

Results of Predator Reduction on Brook Trout and Brown Trout in 4.2 Miles (6.76 km) of the North Branch of the Au Sable River

Abstract During the autumns of 1964, 1965 and 1966, brown trout 12.0–25.1 inches (305–638 mm) in length were removed from 4.2 miles (6.76 km) of the North Branch of the Au Sable River (Dam 2-County Line), and American mergansers were harassed in the same area each winter as time permitted. The objective was to decrease losses among the smaller salmonids which would otherwise be eaten by the large trout and mergansers. Effects of control efforts were assayed by comparison of 1965–1967 angling results and population estimates with similar data accumulated on the test section and two other stream sections of the North Branch during 1961–1964 when predator manipulation was not carried on. In 1964, 561 large brown throut (66% of the estimated population) were removed. In 1965 and 1966, the actual removals were 346 and 104, or 63 and 40% of the population, respectively. The only major change noted was an increase during 1965, 1966 and 1967 in numbers of brook trout larger than 9 inches (229 ram) in the populati...

The Mortality and Growth of Marked and Unmarked Lake Trout Fingerlings in the Presence of Predators

Abstract Two experiments were conducted between October 4, 1948, and October 25, 1949, at the State Fish Hatchery at Marquette, Michigan, to determine the effect of predation on fin-clipped lake trout, Cristivomer n. namaycush [Walbaum], fingerlings. One experiment involved 4,000 unmarked fish and 4,000 clipped fish confined in the presence of adult brook trout, brown trout, rainbow trout, and lake trout. In a smaller experiment, another pond was divided by a fish-tight screen and bulkhead. In the lower half, weighted brush piles were added to provide cover. The upper half was left without cover. Into each half of this pond 500 unmarked fish and 500 marked fish were released, along with various predator fish. The small experimental pond was covered with chicken-wire screen to prevent bird predation. Observation of deaths caused by factors other than predation, plus the counts of survivors at several examinations revealed the numbers of fish lost to the predator fish between various dates. Chi-square analy...