MAINTENANCE AND IMPROVEMENT OF THE AMERICAN FISHERIES. 289 



similar devices operated under the same conditions and taking the same quantities of 

 fish, but at different seasons, may also have widely different influences on the ulti- 

 mate abundance of the species captured. In other words, the character of the appa- 

 ratus does not necessarily afford a basis for determining its effects. A number of 

 modifying causes and circumstances are to be taken into consideration in determining 

 the actual and relative effects of apparatus, among which are: (1) the season when 

 the fish are caught; (2) their condition with relation to the spawning process; (3) the 

 fishing-ground, especially with reference to the shore or the spawning beds ; (4) whether 

 the fish are taken in schools, singly, or in straggling bodies. 



One of the most vital questions now before the fishery interests of the Atlantic 

 coast is the effect of the purse seine on the abundance of mackerel and menhaden, 

 The failure, year after year, of the mackerel fishery has, to many persons, seemed a 

 positive demonstration of the injurious influence of the purse seine. Granting the 

 present relative scarcity of mackerel on our coast to be due to the effects of unre- 

 strained fishing, the fact should not be lost sight of that many more fish were taken 

 in the old days of hook-and-line fishing than have beeu caught with the purse seine; 

 and even conceding that the purse seine is responsible for the conditions now prevail- 

 ing, care must be exercised in ascribing to that apparatus its particular influence in 

 reducing the supply of mackerel, especially in view of the easily verified statement 

 that less fish have thus beeu directly sacrificed than by the methods pursued prior to 

 the introduction of the seine. The qviestion does not seem to be, Has the purse seine 

 caught too many mackerel? but, Has it taken them under conditions that were 

 unfavorable for the continuance of supply? The apparent maintenance of the supply 

 of menhaden on our coast, in the face of an exceedingly large annual catch, even in a 

 circumscribed area like the Chesapeake Bay, is an argument on the opposite side of 

 the question. Similar references might be made in the case of certain other fishes 

 obtained with pound nets, trap nets, and other forms of apparatus which take large 

 quantities of fish and are, in the opinion of some, responsible for the decreases that 

 have occurred, while other fishes captured under the same conditions and in as large, 

 or even larger, numbers, are apparently holding their own. 



While no one attempts to deny that by the reckless use of fishing apparatus in 

 many of our rivers, lakes, and shore waters certain fishes have decreased very 

 noticeably in abundance; aud while it is entirely possible, by the abuse of appliances, 

 to effect almost irreparable injury on the fish supply of more or less circumscribed 

 bodies of water which years of rigid protection and extensive artificial means may 

 not be able to overcome, still it is far from being an easy question to determine to 

 what extent the capture of free- swimming fish in the open waters of the ocean may 

 go without producing a perceptible diminution in the supply or vitiating the natural 

 fecundity of the species. 



I think we have reason to expect that the studies of the life-histories of our 

 economic marine and fresh-water fishes now going on, when taken in connection with 

 investigations of the fisheries for these species, will do much to solve many of the 

 problems aud explain many apparently contradictory phenomena now presenting 

 themselves in connection with our economic fisheries. 



The necessity for restriction in certain lines having been determined by compe- 

 tent authority and proper means, the reform should be promptly and efficiently car- 



F. C. B. 1893—19 



