588 REPORT OF THE COMMISSIONER OF FISHERIES. 
no wild celery, but do have much wild rice. Since the carp have been 
planted, however, this has been largely rooted out; ‘‘they dig it up 
like a drove of hogs, and have about spoiled the marshes for ducks.” 
Mr. C. J. Dregman, of Holland, writes that carp are abundant in 
the lake (Black) and river there, and adds: 
As to their destructiveness to wild celery or otherwise I have no reliable informa- 
tion to give you. There is comparatively little wild celery here, and that which 
does grow here seems not to be affected from year to year. Common report has it, 
however, that carp are destructive to fish eggs and nests. 
Mr. George C. Monroe, of South Haven, does ‘‘not believe they 
cause any damage to plants along the river bank.” At Muskegon, 
according to Mr. E. D. Magoon, ‘‘the marsh is full of channels and 
bayous, and these abound with carp.” Wild celery, rice, and other 
duck food are found here, but he expresses no opinion as to the effect 
of the carp on these. 
Considerable valuable testimony on the question under discussion is 
given by Doctor Smith in his report on the acclimatization of fish in 
the Pacific States (Smith, 1896, pp. 393-403). Several cases are men- 
tioned where carp are reported as destroying the vegetation, most 
notable among which are observations made at what are known as the 
‘*Suisun Marshes.” Doctor Smith (p. 397) quotes a letter from Mr. 
Ramon E. Wilson, secretary of the California Fish Commission, dated 
November 12, 1891, which states that certain portions of the marshes 
referred to above have been preserved by five shooting clubs for a 
period of ten years previously. The letter continues: 
Each of these clubs has, from year to year, supplemented the natural and indigenous 
growth of vegetation by planting non-indigenous seeds and grasses, until about two 
years ago the ponds, ditches, and sloughs had so grown up with vegetable matter 
that upon the opening of the season it was almost impossible to push a boat through 
the dense growth. Last year, the season of 1890, it was discovered that a marked 
change had taken place. The cause was attributed to the winter, which was arather 
severe one, in that there were many overflows and freshets occasioned by heavy 
storms. This year the change in the respect mentioned was much greater. It was 
early reported in the spring that there was very little sign of vegetable growth in any 
of the ponds. Investigation followed, and it was found that fish in large numbers, 
ranging from a few inches in length to 15 pounds in weight, had invaded the grounds 
and taken entire possession of all the waters. These fish came, say, in May and 
remained until about the latter part of July—that is, the bulk, but many remained later. 
We are convinced that these great numbers came to spawn. About August this great 
school, if you can so call it, suddenly disappeared—that is, the larger ones and the 
majority of the whole. Their going was not unlike the grasshopper in effect on vege- 
tation—not a sign or remnant was left. The result is that to-day, where these same 
ponds have heretofore afforded unlimited food supply for surface-feeding ducks in the 
early part of the season and a like supply of celery bulbs for the canvasbacks and 
redheads for the balance of the season, there is absolutely not a single sign of vegeta- 
tion. At the time mentioned I carefully examined the beds of the ponds and found 
them positively barren of vegetable matter. Notwithstanding the emigration, ifit can 
be so called, of the larger fish, the waters are still alive with the same fish, ranging 
from 2 to 8 inches in length. These ponds, heretofore quite clear, are now nothing 
