REPORT OF COMMISSIONER OF FLSH AND FISHERIES. 183 



percli, $0,512 ; and squeteague, $6,722. Terrapin and frogs, of the valne 

 of $2,95)9; crabs, worth $14,700, and crayfish, vahied at $037, complete 

 the list of xnx>dncts. 



Tlie aggregate valne of the Potomac fisheries in 1890 was $485,523, 

 of wlpch snm the fresh- water and anadromons fishes rei^resented 

 $202,082, and the salt-water products, $283,441. ISTo separate figures 

 for the salt-water fisheries are available for comparison, but in 1880 the 

 fresh- water fisheries had a value of $105,503. 



Perhaps the most important feature of the present condition of the 

 fisheries is the large number of pound nets employed. In early times 

 haul seines were the only kinds of apparatus used in the shad and alewife 

 fishery. About fifty- five years ago gill nets were introduced and gradu- 

 ally displaced the seines. Pound nets were first set in the river about 

 1875, and have in turn supplanted the gill nets to a considerable extent, 

 and are now exerting an important influence on the fisheries; 330 of 

 these nets were operated in 1889, 370 in 1890, and 411 in 1891. They 

 are particularly numerous near the mouth of the river, and it is thought 

 that the diminished catch of shad in the upper l^otcmmc which has 

 been observed in recent years has been partly due to the multiplication 

 of these nets in the lower waters. The ultimate effect of the taking of 

 larger and larger quantities of shad and other fish before they have 

 reached the spawning-grounds can not fail to be harmful, and if the 

 fisheries are to be maintained some restrictions will probably soon have 

 to be placed on the number, nature, and location of the nets used, or 

 artificial propagation will have to be conducted on an increasingly exten- 

 sive scale. The greater prominence which the pound net is attain- 

 ing in the shad and alewife fisheries is shown in the following table; 

 notwithstanding that the aggregate catch of both of these gradually 

 declined from 1889 to 1891, the yield in the pound nets advanced each 

 year, and the percentage of increase was marked, while the output of 

 both the seines and gill nets decreased actually and relatively. 



Statcmeut of the aggregate and propoytional catch of shad and alewivcN 'hi. each form of 

 apparatus in the I'oioviac Hirer in 1SS9, 1S90, and ISOl. 



