Table 2. — Recoveries of tagged summer flounder from 1962 inshore 

 releases by season and fisherman type, September 1962-January 1968. 





Number of recoveries by fisherman type 



Period of 



Commer- 



Recrea- 







recovery 



cial 



tional 



Unknown 



Total 



1962 











September 



34 



1 



1 



36 



October-December 



25 



' — 



— 



25 



1963 











January-March 



110 



— 



— 



110 



April-June 



57 



2 



— 



59 



July-September 



79 



8 



1 



88 



October-December 



9 



— 



2 



- 11 



1964 











January-March 



36 



— 



— 



36 



April-June 



26 



1 



2 



29 



July-September 



18 



1 



— 



19 



October-December 



2 



— 



— 



2 



'1965-68 











January-March 



11 



— 



— 



11 



April-June 



7 



2 



— 



9 



July-September 



9 



1 



— 



10 



October-December 



1 



— 



— 



1 



All months 



424 



16 



6 



446 



Percentage 



95.1 



3.6 



1.3 



100.0 



'There were 33 total recaptures for this period; however, month of 

 recapture was available for only 32 of these. 



1 ,006 fish tagged on inshore grounds of Block Island and Nan- 

 tucket Sounds in September 1962 there were 448 recaptures, 

 44.5% of the total released, obtained over a period of 65 mo 

 following tagging. The difference in number recaptured in the 

 two groups and the timespan over which they were recaught is 

 large, considering that both were exposed to approximately 

 similar fishing efforts. We attribute this difference primarily to a 

 greater tagging mortality in the offshore releases, which were 

 from depths of about 90 m and were in less vigorous condition 

 than those tagged inshore, which were from 27 m or less. While 

 the flounders have no gas bladders to cause decompression in- 

 jury, they may have been hurt by the rapid pressure drop as they 

 were brought from deep water to the surface. Tow length may 

 also have been a factor. The fish tagged offshore were caught in 

 tows of 45-60 min duration and therefore may have suffered 

 greater injury in the trawl than those on inshore grounds, which 

 were mostly caught in tows of 30 min. In addition, tows on the 

 offshore grounds frequently contained some spiny dogfish, 

 Squalus acanthias, whose rough skin and spines abrade other 

 fishes in the trawl. 



There was evidence of some tagging mortality among inshore 

 releases, also, based on the tag return rate of newly tagged sum- 

 mer flounder that were recaught during later tagging tows and 

 re-released. In the Block Island Sound tagging, 23 of the tagged 

 fish recaught during tagging tows were re-released in apparently 

 good condition. Of these only four subsequently were recap- 

 tured, for a total tag return rate of 17.4%. This is much lower 

 than the 50% return rate for the Block Island Sound releases as 

 a whole. In addition to this, two of the Block Island Sound 

 releases, which never previously had been recaught, were picked 

 up dead and decomposed a few days after tagging in the trawl of 

 the commercial vessel that had been used during tagging. 



In the course of the Nantucket Sound tagging, 90 of the tag- 

 ged fish were recaught in later tagging tows and re-released. Of 

 these, 10 subsequently were recaptured, a total return rate of 

 11.1%. Again, this was much lower than the 40.8% return rate 

 for Nantucket Sound releases as a whole. 



It seems clear from the above that a significant number of the 

 summer flounder from inshore releases died from the catching 

 and tagging operations. This mortality needs to be considered in 

 estimating population parameters from the tag return data. 



The summer flounder tagged in April 1961 on offshore 

 grounds (Fig. 1) moved during the spring and summer north- 

 west, north, and northeast to coastal areas; there was no move- 

 ment to the south of the Sandy Hook, N.J., area (Figs. 3-5). 

 During the fall the movement was back toward the offshore 

 winter grounds near the outer shelf edge; in the winter all of the 

 recaptures were from the offshore grounds with many of them 

 coming from the vicinity of tagging. Some of the offshore 

 returns, however, were from areas up to about 220 km to the 

 east of the release point, indicating that there also was some 

 eastward movement of summer flounder on offshore grounds 

 (Fig. 5). None of the returns were from areas east of Veatch 

 Canyon and, insofar as is known, this is the eastern limit for 

 movement of this species in any numbers, although they occa- 

 sionally are caught on Georges Bank (Bigelow and Schroeder 

 1953). 



Few of the tag recoveries were from offshore areas southwest 

 of the point of tagging, suggesting that there was little move- 

 ment in that direction (Fig. 5). This apparently was not a result 

 of lack of fishing effort, since New Jersey vessels regularly fish 

 offshore grounds south of Hudson Canyon in the winter 

 (Widerstrom 1959); if any numbers of tagged summer flounder 

 had moved there, it is likely that more would have been caught. 



The general pattern of recoveries from these offshore releases 

 indicated that the summer flounder that move as far north as the 

 winter grounds north of Hudson Canyon become rather perma- 

 nent residents of the northern part of the Middle Atlantic Bight. 



The summer flounder tagged in September 1962 on inshore 

 areas of Block Island and Nantucket Sounds (Fig. 1) moved in 

 the fall and early winter to offshore winter grounds from the 

 vicinity of Veatch Canyon on the east to as far south as 

 Baltimore Canyon (Figs. 9-13). Some of the recaptures from 

 these releases clearly had moved farther south on the offshore 

 grounds than did those from the 1961 offshore releases. There 

 appears to be no clear explanation for this difference, although 

 variations in the winter bottom temperature on offshore 

 grounds may have altered summer flounder distribution, as was 

 suggested by Nesbit and Neville (1935). 



The large cluster of winter returns from the vicinity of Block 

 Canyon (Fig. 10) may be regarded, at least in part, as a function 

 of fishing effort in this intensively fished area. However, the 

 area also is a productive winter fishing ground for squid (Lux et 

 al. 1974), an important summer flounder food. It is possible, 

 therefore, that summer flounder aggregate there to some extent 

 for feeding. 



Tag recoveries during the spring and summer of 1963 and 1964 

 from the inshore releases (Figs. 10-13) show that the fish in these 

 seasons moved back inshore to areas from Long Island to south 

 of Cape Cod. Many were recaught at points of release. The 

 general tendency was for these returns to be made from areas far- 

 ther to the east as the summer progressed. There were very few 

 spring and summer returns from inshore areas south of Long 

 Island, further indicating that fish that had moved to New 

 England waters did not move far to the south in subsequent years. 



The results from the 1961 and 1962 tagging studies showed 

 movement patterns similar to those found for fish tagged in in- 

 shore waters of New York and New Jersey (Westman and 

 Neville 1946; Poole 1962; Murawski footnote 3). The New York 

 and New Jersey summer flounder, however, moved farther 



14 



