Ebook A Comparison of the Diet and Growth of the Trout from the Upper Au Sable and Upper Manistee Rivers, Michigan
The Au Sable and Manistee rivers are among the most prestigious trout streams in Michigan. Much of their fame comes from fishing success in the middle and lower sections of the rivers but little has been reported about the upper sections. This report will focus on the upper sections of these two rivers.
These wooded upper regions are largely uninhabited. Soils of the area are comprised mainly of sand and gravel (Burgis 1977; Coopes 1974), which lead to a high degree of water infiltration into the water table. This provides a stable stream discharge, even during the summer months, which is an important factor in maintaining conditions suitable for the fine trout populations that dominate these rivers (Benson 1953b).
The upper Au Sable trout population is predominantly brook trout (Salvelinus fontinalis) with a few brown trout (-Salmo -trutta) also present. The upper Manistee is dominated by brown trout with some brook trout and a few rainbow trout (-Salmo g airdneri).
This study was threefold in scope. First, the stomach contents of the dominant trout species in each of the rivers were analyzed to determine diet composition. Second, different growth parameters were determined and compared. Third, population estimates were made and age structures determined. In addition to this baseline information a comparison was made between the brown trout of the upper Manistee and the brown trout in the lower Au Sable and the South Branch of the Au Sable (Stauffer 1977).
CONTENTS
ACKNOWLEDGMENTS
ABSTRACT
INTRODUCTION
METHODS
RESULTS
Trout diet
- Upper Au Sable 3.0- to 5.9-inch brook trout
Upper Au Sable 7.0- to 9.9-inch brook trout
Upper Manistee 3.0- to 5.9-inch brown trout
Upper Manistee 7.0- to 9.9-inch brown trout
Total stomach volume total length relationship
Growth as measured by length
Growth as measured by weight
Length-weight relationship
Total volume-total weight relationship
Trout populations
Trout density
DISCUSSION
Seasonal changes in trout diet
- Upper Au Sable 3.0- to 5.9 -inch brook trout
Upper Au Sable 7.0- to 9.9-inch brook trout
Upper Manistee 3.0- to 5.9-inch brown trout
Upper Manis tee 7. 0- to 9.9 -inch brown trout
Total stomach volume-total length relationshi
Growthas measured by length
Growth as measured by weight
Length -weight relations hip
Quantity vs . quality
Total stomach volume-total weight relationship
Trout populations
Trout density
LITERATURE CITED
APPENDIX
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