WIDEGREN MANAGEMENT OF THE BALTIC FISHERY. 121 



among aquatic plants. These fish love to lay their eggs in places where 

 there is a current, as in small streams, the mouths of brooks, &g. The fish 

 of the salmon kind, on the other hand, lay their eggs free, not fastening 

 them to any object, and select for this purpose gravelly and stony places 

 in brooks and rivers, on whose free bottom they lay their eggs. In 

 order to protect the eggs which have been thus laid the fish of the sal- 

 mon kind beat the bottom with their tails, in order thus to cover the roe 

 with gravel and sand. 



Every one who intends to further the propagation of fish and thus to 

 improve the fisheries must, in the first place, ascertain how those fish of 

 which an increase is desired spawn in nature, and then to arrange his 

 course of action in accordance with the knowledge gained. As regards 

 the fish of the salmon kind, whose roe generally takes a longer time for 

 developing, experience has showni that their immber can best be in- 

 creased by protecting the fish during the period it stays in the streams 

 and is occupied in spawning, and also bj'^ introducing artificial proj^aga- 

 tion, that is, impregnating the roe in an artificial manner and keepin;.v it in 

 special establishments until the young fish are large enough to take care 

 of themselves. As there can be no question of establishing hatcliing- 

 places for fish of the salmon kind on the Baltic, as these would have to 

 be made in brooks and streams, this is not the place for describing the 

 arrangement of such establishments; but we shall here mention the 

 various means by which fish-waters may be improved. 



If it is the intention to increase the number of those fish which spawn 

 in spring and whose roe is fastened to branches and other objects in the 

 water, the owner of the water must, first and foremost, see to it that 

 such objects are found in the water. This is all the more important as 

 througii the destruction of the forests, the draining of the marshes, and 

 the gradual rising of the Scandinavian peninsula, the natui'al spawning- 

 places, at least in certain localities, are diminished or deteriorated. By 

 placing in the spawning-places, a short time before the spawning-season 

 commences, fir branches two to three yards long, or fagots, or by laying 

 pieces of sod on the bottom of smaller sheets of water, or by planting 

 aquatic plants which it is known that the bream and other kinds of 

 fish prefer to lay their roe upon, natural spawning-places may be 

 much improved. If such care is to be further extended to the young 

 fish special ponds may be dug and their sides clothed with fagots or 

 suitable aquatic plants. A number of fish which are about to spawn 

 are then placed in these ponds, where they lay their eggs on the fagots 

 or plants. The branches, full of roe, are taken out every day and placed 

 in a smaller jjond 2 feet deep under the water, which by a hedge of 

 fagots is separated from the outer sea, so that large fish and crabs may 

 be prevented from entering the pond and destroying the roe. 



The bream, pike, and ide, which last-mentioned kind loves to lay its 

 eggs in flowing water on a grassy bottom, may be inclosed in separate 

 smaller basins at the mouth of brooks and streams where the above- 



