Planting Fishes in the Ocean 



72 



the water every 6 or 8 minutes. From 

 400,000 to 500,000 cod or similar eggs 

 may be placed in one box, and these hatch 

 with little attention from the fish cultur- 

 ist, owing to the complete oxygenation 

 afforded by the circulation and frequent 

 change of water. The young emerge in 

 10 or II days when the water temper- 

 ature is 46° or 47° F., but the hatciiing 

 may be deferred for 50 days in water of 

 31° F. 



The eggs of the lobster are semi- 

 buoyant and are susceptible to the same 

 methods of hatching as the eggs of the 

 shad — that is, in glass jars from which 

 the young escape as they come from the 

 egg and swim in the zone of water in the 

 top of the jars. As the larval lobsters 

 are cannibals from the moment of their 

 emergence from the egg, it is necessary 

 to keep them constantly stirred and to 

 plant them as soon as possible in order to 

 avoid wholesale mutual destruction. 



EXTENT 01? THE WORK 



The magnitude of the fisheries to be 

 aided and the area of the waters to be 

 stocked have necessitated the most exten- 

 sive fish-cultural operations on the part 

 of the government. The yearly output 

 of the hatcheries must be counted by 

 hundreds of millions, and the efforts 

 should be annuall_v increased in order to 

 offset the increased drain on the supply 

 occasioned by the growing demand and 

 larger numbers of fishermen engaged. 

 Lack of facilities has up to this time pre- 

 vented the rearing of lobsters and marine 

 fishes, and tremendous destruction of the 

 delicate newly hatched fry must thus be 

 discounted by planting the young in far 

 greater numbers than would otherwise 

 be required. During the past ten years 

 the Bureau has planted in New England 

 waters more than 4,450,000,000 arti- 

 ficially hatched fish and lobsters. The 

 output for 1907 was 654,680,000, which 

 was much larger than for any previous 

 year. 



BENEFITS OF MARINE FISH CULTURE 



The difficulty of determining the re- 

 sults of fish culture is greater in the case 



of marine operations than in any other 

 branch. The products of the hatcheries 

 are free to roam so widely and mingle 

 with other fish to such an extent that it 

 is almost impossible to separate the re- 

 sults of artificial propagation from those 

 due to natural reproduction. Indeed, so 

 little conclusive evidence can be adduced 

 in support of marine fish culture that 

 many persons are entirely skeptical as to 

 its benefits. 



As already stated, the Bureau of Fish- 

 eries has proceeded on the h3'pothesis 

 that the effects of man's improvidence 

 with regard to the shore-inhabiting spe- 

 cies can be counteracted by sufficiently 

 extensive artificial measures ; and it has 

 had ample justification for a continuance 

 of its operations in the widespread popu- 

 larity of the work and in the vast amount 

 of unsolicited testimon_y received in the 

 last twenty years showing the apparent 

 increase in the abundance of the species 

 handled at the hatcheries. 



It was about 1889, some ten or twelve 

 years after cod cultivation was system- 

 atically begun, that the first results began 

 to be manifested. Schools of small fish, 

 of marketable size, appeared on inshore 

 grounds that either had never before had 

 runs of cod, so far as known, or had 

 been visited by only limited numbers of 

 such fish. Careful observations con- 

 ducted by the Bureau had traced the an- 

 nual growth of the artificially hatched 

 fry in the coastwise waters, and had left 

 little doubt that the immense bodies of 

 cod that had recently appeared were the 

 direct outcome of the hatchery work. 

 The fishermen were quick to take advan- 

 tage of the new run of fish, and it was 

 estimated that in 1889 the fishermen of 

 southern New England had caught cod 

 to the value of $250,000 on grounds 

 where regular cod fishing had never be- 

 fore been profitable. The abundance of 

 the so-called "hatchery cod" in the in- 

 shore bays and sounds has continued 

 without interruption, and a definite fish- 

 ery has been established. Furthermore, 

 a most lucrative small-boat fishery has 

 been built up on the shores of New York 



