Premium
The Effects of Deflectors in a Section of a Michigan Trout Stream
Author(s) -
Shetter David S.,
Clark O. H.,
Hazzard Albert S.
Publication year - 1949
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1946)76[248:teodia]2.0.co;2
Subject(s) - trout , fishing , salvelinus , fontinalis , fishery , environmental science , fish <actinopterygii> , population , catch and release , current (fluid) , volume (thermodynamics) , hydrology (agriculture) , zoology , biology , geology , oceanography , demography , geotechnical engineering , physics , quantum mechanics , sociology , recreational fishing
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 Preliminary and unpublished bottom‐food studies indicated a decrease in total number and volume of all organisms but an increase in forms found most frequently in trout stomachs.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 after the addition of deflectors, attended by a slight decrease in average size. Average creel‐census figures for the 3 years prior to stream improvement and the 5 years after show an increase after improvement of 120 percent in the total catch and of 46 percent in pounds caught per hour coincident with a 64 percent increase in angling pressure. It was demonstrated that migration into the section improved was not responsible for the increases noted, also that bordering sections failed to have fishing comparably good to that produced in the improved section. It was concluded that the improvement in brook trout fishing in the experimental section was the result of an increase in number, size, and depth of pools created by installation of current deflectors.