BULLETIN OF THE UNITED STATES FISH COMMISSION. 7 



to construct and put in working order about 120 hectares of spawning- 

 ponds. According - to Mr. von dein Borne's former experience, the 

 result would be still more favorable. He found that a good spawning- 

 pond produces on an average 50,000 to 75,000 young carp, per hectare, 

 in one year, so that 80 to 90 hectares of spawning ponds would be 

 sufficient to stock the Stettiner Haff with the required quantity of 

 carp within four years. 



In answer to the question, whether there are near the Stettiner Haff 

 places suitable for the construction of such ponds, the administration 

 of forests for that part of the country has returned an affirmative an- 

 swer. In the extensive government forests on the western shores of 

 the Stettiner Haff, between Uckermiinde, Politz, and the Papenwasser, 

 there are a number of marshy places which, as far as their productive- 

 ness as forest land is concerned, are practicall} 1 " useless. With very 

 little trouble, in man3 T cases by merely constructing a dike with a pipe 

 for draining off the water, very fine sjjawning-ponds for carp could easily 

 be constructed in the immediate neighborhood of the Stettiner Haff. 

 Only nine full}' matured carp per hectare, each weighing about four 

 pounds, placed in these ponds in the spring, would in the autumn of 

 every year yield 40,000 to 70,000 young carp per hectare. If one wishes 

 to save the expense of constructing a number of ponds, it will be suffi- 

 cient to commence with one pond, and let the young carp grow large 

 enough to become spawning carp after three years, and then stock the 

 other ponds with these carp. The transportation of the young carp to the 

 Stettiner Haff could be accomplished by wagons or by trenches leading 

 from the Haff into the ponds ; and this should be done every year in 

 October. The question arises whether the Haff is suitable for carp 1 or 

 if wind and Avaves, and the numerous enemies of the carp, especially the 

 pike, or lack of food, or the salt water from the Baltic which occasion- 

 ally enters the outer mouth of the Oder, might injure the carp? In 

 reply we must say that the carp lives under the same conditions as the 

 bream, and is everywhere found in its company; and since we find the 

 bream in the Stettiner Haff, there is not the slightest doubt that the carp 

 can also live in these waters. We must of course be prepared to see the 

 Haff pike, that most voracious fish of prey, devour many thousands of 

 the delicate young carp, and the herons, gulls, sea-eagles, and other ene- 

 mies of the carp do their share in destroying the young fish. Very prob- 

 ably the most dangerous of all enemies of the carp, man, will capture the 

 young fish before they have reached their full size ; but there is no doubt 

 that the flat bottoms of the Haff, which, especially in the west, are rich 

 in the best humus, will provide an inexhaustible supply of food for the 

 carp, and afford many excellent places of refuge. Against the fish-of- 

 prey we shall declare open war, and as for man, the fiercest of these 

 enemies of the carp, is concerned, we shall endeavor to limit his power 

 for evil by carrying out a long and often talked of plan, viz, to build a 

 swift small steamer, which will act as the policeman of the Haff. Mill- 



