340 Memoir Sears Foundation for Marine Research 



Fluctuations. Overfishing, pollution, and impassable dams in streams have been the 

 chief factors in diminishing the abundance of "Alewives" in many localities, but all of 

 these causes can be remedied at least in some measure by restocking suitable streams 

 with gravid fish (j6: i io; et al.). This has been done in Massachusetts localities, where, 

 in the third year after the ripe fish were introduced, the progeny appeared in those 

 streams. 



It is not always easy to determine whether an increase or decrease in catch is due 

 to the amount of fishing, to special conditions created by man, to successful or unsuc- 

 cessful spawning, or to general conditions obtaining in nature. However, if the increase 

 or decrease extends over a period of several years, reasonable conclusions may be reached. 

 For example, the tremendous abundance of "Alewives" in the Chesapeake Bay area in 

 1908 and 1909, when the catches were about twice those in preceding and successive 

 censuses (66,690,000 and 51,425,000 pounds), may be ascribed to especially favorable 

 conditions during and probably after the spawning season. On the other hand, the 

 general decline in the fishery in New England (discussed above), despite some 

 fluctuations, quite surely was the result of adverse conditions created by man. There- 

 fore, frequent censuses are necessary to show the status of this as well as other fisheries 

 for the guidance of those entrusted with the promulgation of regulations for the con- 

 servation of the fishery. 



Artificial Cultivation. "Alewives" have not been artificially propagated regularly be- 

 cause it has not been deemed necessary. However, in 1882 two million fry hatched 

 by fish culturists were transported to the Colorado River, Texas (45: 586), an in- 

 troduction that apparently was not successful. As already stated, another method 

 of "planting" was successfully used in Massachusetts. Some depopulated streams in 

 that state, which had been reconditioned and made suitable, were successfully restocked 

 merely by releasing gravid fish. Graybacks apparently were unintentionally introduced 

 into Lake Ontario when shad fry were planted there (^5: 588; I18: 188). 



Methods of Fishing. "Alewives" are easily caught, chiefly with dip nets in New Eng- 

 land. Pools are constructed about the mouths of rivers and the gravid fish are led into 

 them by means of nets and stone diversions. Southward, as in the Chesapeake Bay 

 area and in North Carolina, they are caught chiefly with pound nets. However, they 

 are taken also with weirs, seines, gill nets, fyke nets, and a few with otter trawls. 



Range and Distribution. The range of pseudoharengus extends from the Gulf of St. 

 Lawrence and Nova Scotia, where it is common {l2g : 54), to North Carolina. It has 

 been recorded for the St. Johns River, Florida, but the first report {45: 336), as 

 Clupea vernalis, was apparently based on a P. aestivalis (USNM 17929, collected by 

 Spencer F. Baird), now before me; and the second report, so far as known, by Lonn- 

 berg (88: 114), may be disregarded, for this species is too difficult to distinguish 

 from P. aestivalis by a simple "observation." According to Smith, "extensive collec- 

 tions of fishes in the St. Johns River, in Florida, have failed to disclose its presence" 

 {ll^'. 122). Indeed, no specimens of this species from south of the Albemarle Sound 

 area (where aestivalis is plentiful) have been found in the National Museum, and 



