CV111 ARTIFICIAL CULTIVATION OF FISH. 



4. The effects of misplaced energy' in fishermen and poachers is a 

 subject too vast to do more than allude to in this place, but the especial 

 attention of legislators ought to be drawn to the fact that increased present 

 productiveness may be carried on at the expense of future years' supply, and 

 multiplying modes of destruction does not invariably tend to the benefit of 

 the fisherman or of the consumer. 



5. Injuries occasioned by the lower animals are numerous, and differ 

 somewhat in the adult stage from what they do among the ova and young. 

 Adult fish suffer greatly from porpoises and their allies, otters, birds and 

 various species of their own kind ; whilst the ova and fry may be destroyed 

 by rats, birds (even robins), watersnakes, newts, frogs, leeches, and a variety 

 of other agencies. 



ARTIFICIAL CULTIVATION OF FISH. 



The cultivation of fish has for its chief object an increase in the number 

 or size, and likewise an improvement in the breed of those in fresh waters, 

 or even of the sea, not only by direct cultivation of the finny tribes, but also 

 of the food on which they subsist, and an eradication of what may be 

 detrimental to their prosperity. This would include whatever assists them 

 in their ascent or descent of rivers, when doing so to continue their 

 kind or maintain the life of each individual (see figure of fish-pass, 

 page lxxviii). When inland fisheries are impoverished the aid of 

 legislation has generally to be invoked, in order to protect what is left, 

 permit nature to play her part in their recovery, and, if necessary, to have 

 desirable forms artificially propagated. 



Our inland waters consist of such as streams or rivers, broads, canals, 

 lakes, and ponds : while some rivers are rapid and clear, others are sluggish 

 and more or less muddy. Different classes of fish inhabit these various 

 localities ; those most esteemed and generally looked upon as game-species 

 are the Salmonidse, while the coarse fish consist of perch, pike, and members 

 of the carp family. As a general rule the first are found in running 

 water and lakes, whereas the latter prefer more sluggish streams, broads, 

 and ponds. 



The artificial cultivation of salmon and trout has been found necessary 

 in these islands, for reasons already stated (page lxx), and a great gain 

 would have accrued were it not for the over-fishing which is now permitted 

 in the lower reaches of the rivers (page ciii). The ova of the Salmoriidas 

 can be obtained from fish captured in the waters they frequent, or their 

 redds in the rivers and streams may be plundered, or the parents may be 

 purposely kept in breeding-ponds. 



