Table 6. — Summary of the distances traveled by recaptured tagged American lobsters at 

 each tagging area, 1975-77. 





Kennebunkport 



Boothbay Harbor 



Cumulative 



Jonesport 



Nautical 





Cumulative 





Cumulative 



miles 



Number 



% 



Number 



% 



Number 



% 



traveled 



returned 



returned 



returned 



returned 



returned 



returned 



0-1 



219 



30.8 



56 



10.0 



311 



38.0 



2-3 



368 



82.4 



112 



26.9 



264 



70.2 



4-5 



111 



98.0 



291 



73.6 



174 



91.5 



6-7 



8 



99.2 



140 



96.0 



58 



98.5 



8-9 



1 



99.3 



12 



97.9 



3 



98.9 



10-11 



3 



99.7 



7 



99.0 



1 



99.0 



12-13 









2 



99.4 



4 



99.5 



14-15 









2 



99.7 









>15 



2 



100.0 



2 



100.0 



4 



100.0 



Total' 



712 





624 





819 





'These values are less than total number of recaptures reported in Table 1 because location 

 of recapture was not known for all returns. 



KENNEBUNKPORT 

 BOOTHBAY HARBOR 

 JONESPORT 



91-95 96- 100 IOI-I05 



CARAPACE LENGTH (mm) 



Figure 9. — Distances moved by recaptured American lobsters of various sizes 

 tagged and released at Kennebunkport, Boothbay Harbor, and Jonesport, 

 Maine. 



lobsters were free longer than 1 yr prior to being caught. 

 Perhaps, at least for the larger lobsters, reductions in times at 

 large may have curtailed movement. 



Mortality 



Mortality rates were estimated from a linear regression of 

 the number of tagged lobsters recaptured on the time at large. 

 Regression coefficients were substituted into Gulland's (1969) 

 equation (6.3): 



log e n r = -(F+M)rT + log £ 



where the 

 intercept (a) = log 



FN n 



T+W 



FN n 



( 1 _ e-V+Afl, 



slope (b) = -(F+M) r T 



n f = number of recaptures during interval r, 



where r = 0, 1, 2, 3 ... weekly, biweekly, or monthly 

 period following release 

 T = length of interval of time (r) 

 N = number of tagged lobsters released. 



Because an estimate of total mortality, derived with tagging data 

 along, is the sum of fishing mortality (/) plus not only natural 

 mortality (M), but also all other causes of reductions in the 

 number of tagged animals, the value ' 'A" ' (all sources of tag loss 

 plus natural mortality) should replace M in the equations. 



The number of recaptures plotted over time indicated that 

 return rates increased during the first 4-8 wk, then leveled off 

 for a brief period and eventually began to decrease (Fig. 10). 



KENNEBUNKPORT 



a * 



10 12 14 16 18 20 22 24 26 28 30 32 34 36 



6 



I 5 



S 4 



E 

 - 3 



-2 











8 



W E E K LY 



r 





BOOTHBAY HARBOR 





& 



BI-WEEKLY 



O 









a 



MONTHLY 



a ° • o 



e 





















o 













- 





c 



© 





uJ 





A 









& 



A 









e 





A 



2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 



_i i l i i ' ' 



_| — i l_l i i i i i 



2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 

 TIME AT LARGE (Wtekl) 



Figure 10. — Recaptures (logg scale) of tagged American lobsters as related to 

 time at large at each lagging area. 



Increases in the number of recaptures during the first few suc- 

 cessive weeks following release may be attributed to slow mix- 

 ing of tagged animals with the fishable population in associa- 

 tion with spatial variations in fishing intensity. Accordingly, 

 mortality estimates were calculated from return data exclusive 

 of those initial recovery intervals (2-4 wk) when mixing of tag- 

 ged and untagged individuals was considered to be incomplete. 



10 



