DISK TAG 



NICKEL PIN 



c 



130456 



") BELLY TAG 



(bFU/AOn RETVUNTOBUMAUOF A 



Figure 13.— Types of tags used in the study of scup migrations. 



by the results of these tagging experiments, 

 for they suggested the possible existence of 

 two independent population units in the sum- 

 mer fishery from New Jersey to southern New 

 England. For example, the returns of tagging 

 suggested one unit common to southern New 

 Jersey and another to southern New England. 

 Scup marked and released in the autumn of 

 1931 off southern New Jersey migrated to the 

 region of the winter trawl fishery off the 

 Virginia Capes as indicated by returns in the 

 first winter subsequent to tagging and returned 

 in the following spring to the general area in 

 which they were tagged (fig. 14, table 20). No 

 recaptures were reported north of the central 

 part of the coast of New Jersey (north of 

 Atlantic City). On the other hand, scup tagged 

 and released in several summers at Woods 

 Hole, Mass., were recaptured in the first 

 winter following the tagging period in the 

 southern winter fishery. In the subsequent 

 spring and summers, most of the Woods Hole 

 scup returned to the region of tagging; a few 

 were taken as far westward as the western 

 end of Long Island, N.Y., but of the 24 summer 

 recaptures, only 4 were reported from New 

 Jersey, and these were all from the northern 

 part of the State (fig. 14, tables 20, 21). 



It is admitted that the small number of 

 returns (less than 2 percent) from these 



experiments casts some doubt on the relia- 

 bility of a conclusion that separate units 

 exist near the southern and northern ends 

 of the range of the species. Similar re- 

 sults were secured from each of five ex- 

 periments carried out in each of 4 years 

 so that the segregation cannot be looked upon 

 as reflecting exceptional behavior in a single 

 year. 



The suggestion that the New York-southern 

 New England fishery draws on a population 

 unit separate from the New Jersey fishery 

 as indicated by tag returns is not clearly 

 evident from the analysis of biological and 

 catch record data. It has been demonstrated 

 that the same year classes that have been 

 present in the New Jersey fishery have ap- 

 peared subsequently in the pound net and trap 

 fisheries at Fire Island, N.Y., and Newport, 

 R.I. (fig. 6) and that at the latter places the 

 catch has increased simultaneously with the 

 appearance of these fish. If this is the result 

 of an incursion of the same fish that were 

 present along the New Jersey coast in the 

 preceding year or two, it is in opposition to 

 the results of the tagging experiments, for 

 the latter would suggest that the New Jersey 

 and the New York-Rhode Island fisheries draw 

 on different population units rather than the 



48 



