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Page:Popular Science Monthly Volume 61.djvu/206

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POPULAR SCIENCE MONTHLY.

little doubt that the salmon fry in fresh water is able to take care of itself.

Our most extended observations were made on the migratory habits of the fry, and I give a somewhat detailed account of them. In May and June, 1898, we visited all parts of the Sacramento River, from its source to Suisun and San Pablo bays, and even traveled 250 miles down the river in a rowboat. We were equipped with fine-meshed seines which we used wherever it seemed practicable or desirable to gain information concerning the young salmon. We found them abundant everywhere above the middle portion of the river, and in a decreasing number all the way down to the mouth, and along the shores of the bays. We considered them abundant when we caught anywhere from 25 to 400 at a single haul of a 50-foot seine. They were about two inches long wherever taken. The same observations were made again in July. In the headwaters, at the Sims, the fry were as abundant as at the previous examination. There were fewer at Redding, very few at the mouth of Battle Creek, and none at all below the latter point. All that we had found on the previous examination had gone down stream and had passed into salt water. As we afterward learned, the salmon fry observed during this first examination were merely the last of the season's migration, and not all of it, as we first supposed.

While at Battle Creek Hatchery during October and November, 1898, we continued the observations by setting a trap in Battle Creek, and so arranging it that it caught only such fishes as were going down stream. By this means we soon learned that the fry begin their migration much earlier and younger than our previous summer's work had led us to suppose. The following is a record of the daily catch of the trap:

Date. Time. No. Date. Time. No.
Oct. 7 Day 0 Nov. 12 Night 6
" 8 Night 5 " 13 Day 0
" 9 Night 1 Night 26
" 11 Night 3 " 14 Night 27
" 12 Night 17 " 17 8-9 P. M. 17
" 13 Day 0 " 21 3-4 A. M. 83
Night 7 " 22 4-5 A. M. 6
" 14 Day 0 " 24 12-1 A. M. 1
Night 10 " 25 1-2 A. M. 5
" 16 Day 0 " 26 1-2 A. M. 15
Night 8 " 27 2-3 A. M. 0
" 17 Day 0 " 28 2-3 P. M. 0
Night 6 " 30 1-2 A. M. 49
" 21 Night 11 8-9 A. M. 24
" 24 Day 0
Night 2
" 25 5-9 P. M. 4
Night 6