BULLETIN OF THE UNITED STATES FISH COMMISSION. 189 



the Gross Scbauener Lake, which had barely the regulation size — 35 

 ceutinieters [13f inches] — and weighed ^ pound apiece. As my prede- 

 cessor had to give up the lake in the following year, he took out as 

 many of the then 4-year-old bass as he could possibly get. But their 

 nninber seemed to have been but little decreased thereby; and as but 

 few bass, either larger or smaller than these, could be noticed, tlie 

 growth of the fish which had been hatched in 1877 could be traced dis- 

 tinctly. By next year, in the autumn of 1882, these bass had reached 

 a weight of f to 1 pound; in the following autumn, IJ to li pounds ; in 

 ]884, 2 pounds; and this autumn (1885) these eight and a half years old 

 bass weigh fully 3 pounds, so that evidently the largest increase of weight 

 has been this year. If I had caught many of the young bream referred 

 to above a year sooner, or taken out the young i^erch sooner, both these 

 kinds would possiblj^ not have disappeared. It probablj^ has not been 

 a mistake to take the young bass so soon, as otherwise they would have 

 died out of themselves. As it is, they have so far been caught in large 

 numbers every year ; and in spite of this there are many left, while but 

 few older or younger bass are caught. But the most convincing proof 

 of the fact that extensive fishing is not injurious as long as there is a 

 good stock offish, is furnished by the quantity of marenas in the Wer- 

 bellin Lake. 



These and similar cases have not been thus far generally made 

 known, although the fishermen could give many such instances. A gen- 

 eral and sudden dying out of fish becomes known much quicker, because 

 it is more striking, and because the proofs of the occurrence are evident. 

 The causes of such occurrences are frequently ascertained to be impure 

 or poisoned water. The lack of fresh air also is dangerous, especially 

 in winter when the ice is thick. But it also happens that only one kind 

 of fish dies out, while others continue to live and flourish. Thus eight 

 or ten years ago all the bass in the Strauss Lake died at the same time ; 

 and it was impossible to surmise the cause, for it can hardly be sup- 

 posed that it should have been caused by a thunder-storm ; and as the 

 lake is very large and deep, it is not easy for its water to become im- 

 pure or too warm in summer. In consequence those fish of which there 

 is an abundance have to be caught more freely ; but, on the other hand, it 

 will be advisable to aid those fish which are not found in such large num- 

 bers by prohibitory measures, or by planting young fry. In this respect 

 I can record rapid success as regards tench and eels. But as this can 

 be done only in inclosed waters, or wherever the fisheries are managed 

 by joint stock companies — of either of which we have none too many — 

 we shall h^"dly be able to look for any rational fisheries. 



If we ask how it comes that in one year there is so much young fry, and 

 again in several successive years hardly any, many different answers may 

 be given. In one case there may be a lack of good si)awniug places; 

 then again the v.'eather may have been unfavorable; and in other cases 



