migration but they illustrate the kind of exceptions that 

 inevitably arise in attempted classification of the 

 movements of tagged animals over a short term; the long 

 distance traveled by 237F and 303M, both at high rates 

 of speed, tend to infer directionality on their movements 

 that are inconsistent with our hypothesis; the close 

 agreement of the track bearings might well be coin- 

 cidence, but a rational conclusion, nevertheless, is that 

 the tracks are similar results of disoriented attempts to 

 return to original release depth. 



The exceptions noted above notwithstanding, the 

 balance (25) of these migrants effected movements that 

 were highly consistent in directionality, time at large, 

 and distance. Inspection of Appendix Table 22 shows 

 that all were recaptured within the range 20-89 days at 

 net distances from point of release ranging from 22 to 48 

 miles (40.8-89.0 km); bearings of the net tracks are con- 

 fined to the narrow range 300° -341° with effective shoal- 

 ing ranging from 17 to 25 fathoms (31.1-45.7 m). This 

 particular group of defined migrants amply supports our 

 prevailing hypothesis and serves to illustrate better than 

 any other the concept of the outbound (shoalward) phase 

 of seasonal migration. 



Composite Station 23 (See Figure 25 and 

 Appendix Table 23) 



Thirty-four recaptures have been reported from a 

 composite total of 301 releases near the east flank of 

 Welker Canyon on 19 and 20 June 1969. Mean depth at 

 first capture was 61 fathoms (112 m); mean depth at 

 release was 82 fathoms (150 m). Twenty-eight lobsters 

 were reported by specific location and two by ap- 

 proximate location. Sex ratio at release was 139 females 

 (46%) to 162 males; the ratio at return was 20 females 

 (59%) to 14 males. 



Mean time at large for all accountable (32) recoveries 

 was 249 days (0.7 yr); greatest time at large for a located 

 individual (848F), an egg-bearing female at release, was 

 506 days (1.4 yr) with recapture 16 miles (29.7 km) from 

 original release point. 



Mean distance traveled by individuals with specific 

 capture locations (28) was 35 miles (64.9 km); eight in- 

 dividuals (576F, 728F, 771F, 562M, 564M, 767M, 769M, 

 797M) surpassed the 50-mile (92.7-km) range from point 

 of release with two of these (728F, 797M) exceeding 100 

 miles (185 km). Maximum dispersion of 126 miles (234 

 km) westerly was accomplished by 728F while at large 

 348 days (0.95 yr); this individual bore ripe external eggs 

 at recapture which, coupled with zero growth over the 

 period at large, implies that egg deposition occurred 

 shortly after release. 



Only four of the recaptures qualify as migrants; all 

 were recaptured in significantly shoaler water with at 

 least three of the four effecting large-scale movements 

 over relatively short term. Calculated bearing, ground 

 speed, and depth change of these migrants are given 

 below: 



Return no. 



Bearing 



mi/day 

 1.1 



km/day 

 2.0 



fathoms 

 +59 



meters 



576F 



313° 



+ 108 



584F 



344° 



0.5 



0.9 



+51 



+93 



562M 



285° 



5.0 



9.3 



+52 



+95 



564M 



282° 



5.5 



10.2 



+50 



+91 



The net tracks exhibited by 576F and 548F approach 

 the idealized view of directed shoalward movements; the 

 tracks of 562M and 564M are good, in the comparative 

 sense, but less than ideal in terms of the best vector 

 toward shoaler water. These two migrants rank first and 

 third for calculated ground speed among the 117 defined 

 migrants. 



Probable migrations are evident in the respective 

 locations of at least four other individuals (767F, 769M, 

 797M, 771F); each of these lobsters was recaptured ap- 

 proximately 1 yr after release at depths (20-35 fathoms = 

 36.6-64.0 m) consistent with hypothesized summertime 

 distribution. It should be noted that here, as elsewhere, 

 perambulations beyond one season cannot be ap- 

 proximated by a straight-line track; this simple conven- 

 tion is probably a valid estimator in cases of defined 

 migrants, but where movements are summed over two or 

 more migration cycles, the track-line can be nothing 

 more than a measure of temporal displacement from 

 point of release. 



Composite Station 24 (See Figure 26 and 

 Appendix Table 24) 



Twenty-two recaptures have been reported from a 

 composite release of 173 lobsters 10 miles (18.5 km) west 

 of Oceanographer Canyon on 19 and 22 June 1970. Mean 

 depth at first capture was 59 fathoms (108 m); mean 

 depth at release was 57 fathoms (104 m). Fifteen lobsters 

 were reported by specific location and four by ap- 

 proximate location. Three recaptures were reported 

 without location information of any kind. Sex ratio at 

 release was 72 females (42%) to 101 males; the ratio at 

 return was 14 females (64%) to 9 males. 



Mean time at large for all accountable (22) recoveries 

 was 290 days (0.8 yr); greatest time at large for a located 

 individual (883F), a mature female at release, was 512 

 days (1.4 yr) with recapture 18 miles (33.4 km) from 

 release point. 



Mean distance traveled by individuals with specific 

 capture locations (15) was 24 miles (44.5 km); two in- 

 dividuals (569F, 648M) surpassed the 50-mile (92.7-km) 

 radius of dispersion. Recapture 569F, the only qualified 

 migrant among the returns, moved 74 miles (137 km) 

 southwesterly in 16 days (4.6 miles/day = 8.5 km/day) to 

 equivalent depth near Veatch Canyon; recapture 648M 

 was taken 136 miles (252 km) westerly near Block Can- 

 yon following 207 days at large. 



Composite Station 25 (See Figure 27 and 

 Appendix Table 25) 



Ten recaptures have been reported from a composite 

 release of 60 trap-caught lobsters near Block Canyon on 6 



17 



