of 1 mile (1.85 km) per day along hypothetical track lines 

 that are probably realistic approximations of actual 

 tracks made good; the latter (570M) was recaptured 14 

 mo after release and shows a net displacement of 115 

 miles (213 km). In this situation, the track is simply a 

 straight-line resolution of some unknown number of 

 movements over long term which have resulted in a ma- 

 jor westerly displacement; the timing and directionality 

 of the component steps cannot be deduced or inferred 

 from the available information. 



The defined migrants (13) within this group are listed 

 below with ground speed and depth change: 





Ground speed 



Depth change 



Return no. 



mi/day 



km/day 



fathoms 



meters 



255F 



0.6 



1.1 



+45 



+82 



294F 

 654F 

 H6F 



1.1 

 1.1 

 0.4 



2.0 

 2.0 

 0.7 



+47 



+32 







+86 



+59 







152F 



0.4 



0.7 



-7 



-13 



184F 



0.4 



0.7 



+10 



+ 18 



191F 



0.3 



0.6 



+ 15 



+ 27 



282F 



0.1 



0.2 



-25 



-46 



246M 



0.8 



1.5 



+48 



+88 



290M 



0.5 



0.9 



-25 



-46 



317M 



1.4 



2.6 



+38 



+70 



190M 



0.3 



0.6 



+ 15 



+ 27 



194M 



0.4 



0.7 



+ 10 



+18 



Composite Station 20 (See Figure 22 and 

 Appendix Table 20) 



Forty-four recaptures have been reported from a 

 composite total of 387 releases made 25 miles (46.3 km) 

 southwest of Corsair Canyon over the 3-day period, 7, 8, 

 and 9 May 1969. Mean depth at first capture was 173 

 fathoms (316 m) with range 160-180 fathoms (293-329 

 m); depth at release for all releases was 50 fathoms (91.4 

 m). Thirty-seven recaptures were reported by specific 

 location and one by approximate location. Sex ratio at 

 release was 274 (71%) females to 113 males; the ratio at 

 return was 29 (66%) females to 15 males. 



Mean time at large for accountable (44) recoveries was 

 199 days (0.5 yr); greatest time at large for a located in- 

 dividual (897M), a mature male at release, was 1,075 

 days (2.9 yr) with recapture 27 miles (50.0 km) from 

 release point. 



Mean distance traveled by individuals with specific 

 capture locations (37) was 30.4 miles (56.3 km); four in- 

 dividuals (306F, 315F, 578F, 697F), all sexually mature 

 females, equalled or exceeded the 50-mile (92.7-km) 

 range from point of release. Maximum dispersion (143 

 miles = 265 km) was attained by 697F which was recap- 

 tured near Veatch Canyon 761 days (2.1 yr) following 

 release. This group of recoveries includes the second 

 largest number (21) and percentage (56) of definable 

 migrants, 21 of 37. Collectively, the migrants are 

 characterized by relatively large size, a high proportion 

 (76%) of females, and, among the females, a high propor- 

 tion (44%) with external eggs at release. 



The defined migrants (21) within this group are listed 

 below with track bearing, ground speed, and depth 

 change: 



Ground speed Depth change 



Return no . Bearing mi/day km/day fathoms meters 



148F 



056° 



1.0 



1.9 



-85 



-155 



161F 



227° 



0.8 



1.5 



-40 



-73 



244F 



329° 



0.5 



0.9 



+ 16 



+ 29 



252F 



329° 



0.5 



0.9 



+ 16 



+ 29 



259F 



327° 



0.7 



1.3 



+23 



+42 



276F 



337° 



0.5 



0.9 



+ 18 



+33 



277F 



337° 



0.5 



0.9 



+ 18 



+33 



306F 



323° 



0.5 



0.9 



+22 



+40 



314F 



314° 



0.6 



1.1 



+ 23 



+42 



315F 



315° 



0.6 



1.1 



+23 



+42 



171F 



036° 



0.3 



0.6 



-45 



-82 



198F 



222° 



0.4 



0.7 



-35 



-64 



209F 



079° 



0.2 



0.4 



-42 



-77 



228F 



225° 



0.2 



0.4 



-30 



-55 



239F 



079° 



0.2 



0.4 



-32 



-59 



247F 



009° 



0.3 



0.6 



+ 11 



+20 



149M 



056° 



1.0 



1.9 



-85 



-155 



150M 



043° 



1.0 



1.9 



-85 



-155 



200M 



334° 



0.8 



1.5 



+ 13 



-24 



285M 



325° 



0.5 



0.9 



+ 20 



-37 



210M 



079° 



0.2 



0.4 



-32 



-59 



It will be noted from the preceding table and Figure 22 

 that 10 of the 11 migrants showing shoalward displace- 

 ment were recovered within a 33° arc relative to release 

 point; the significance of this tight grouping is evident 

 only when the recovery positions are plotted on a detailed 

 bathymetric chart of the area encompassed from which it 

 can be seen that the recapture locations are coincident 

 with several areas that are heavily fished in summer 

 months by trawlers fishing primarily for yellowtail 

 flounders. The rugged topography of Georges Bank 

 shoalward of 30 fathoms (54.9 m), coupled with strong 

 tidal currents, greatly limits trawler activity and hence 

 the incidental catch of shoaling lobsters to those areas 

 that are topographically compatible with otter trawl 

 fishing. The relatively large number of tagged lobsters 

 recaptured on this shoaler part of Georges Bank (see also 

 Fig. 24 and related discussion) indicates that this upper 

 reach of the Bank as a whole supports a major summer- 

 time concentration of lobsters originating from the con- 

 tinental margin and slope from Veatch Canyon eastward. 



Composite Station 21 (See Figure 23 and 

 and Appendix Table 21) 



Twenty-three recaptures have been reported from a 

 single point release of 166 lobsters near the head of 

 Lydonia Canyon on 6 June 1969. Depth at first capture 

 was 70 fathoms (128 m); depth at release was 57 fathoms 

 (104 m). Fifteen recaptures were reported by specific 

 locations and six by approximate location. Sex ratio at 

 release was 82 females (49%) to 84 males; the ratio at 

 return was 7 females (30%) to 16 males. 



Mean time at large for all accountable (19) recoveries 

 was 264 days (0.7 yr); greatest time at large for a located 

 individual (851M), a mature male at release, was 885 

 days (2.4 yr). 



15 



