Regression plots, equations and growth parame- 

 ters for all lobsters (n= 987), males (n= 381) and 

 females (n = 606) are presented in Figure 7. 

 Growth per molt for all lobsters averaged 13.3% 

 from 1986-87 and 13.9% from 1978-85. Female 

 growth per molt averaged 13.9% during 3-unit 

 operations and 13.7% prior to Unit 3 start up. 

 Males had lower growth per molt during the 

 1986-87 studies (12.3%) compared to the pre- 

 operational studies ( 14. 1 %). However, lower val- 

 ues for male growth (12.3%) had been reported 

 in previous years (NUSCO 1980). In eastern 

 LIS, Stewart (1972) reported 15.8% growth per 

 molt for males, and 15.4% for females. Briggs 

 and Mushacke (1984) reported 14.5% growth per 

 molt for males and 12.5% for females in western 

 LIS. Higher growth increments were reported by 

 Cooper and Uzmann (1980) for an offshore lob- 

 ster population, 18.7% for males and 16.7% for 

 females. They attributed the lower growth of the 

 inshore population to lobster inactivity during the 

 colder months of the year. 



Claw Loss 



The percentages of lobsters caught missing one 

 or both claws (culls) in 1986 (10.6%) and 1987 

 (10.3%) were lower than the average percentage 

 culled in previous years (10.6%-15.5%) (Table 

 9). The proportion of culls at each station was 

 similar in 1986 and 1987. The highest percentage 

 of culls occurred at Intake, 14.7% in both 1986 

 and 1987, followed by Jordan Cove, 10.9%-11.9% 

 and Twotree 6.8%-6.5%. The percentage of culls 

 at Twotree has been lower than at the nearshore 

 Jordan Cove and Intake stations since this study 

 began (NUSCO 1987a). Working in eastern LIS, 

 Smith (1977) reported 26.4% claw loss, whereas 

 Briggs and Mushacke (1979) reported claw loss 

 varying between 7.4 and 22.8% in western LIS. 

 Since 1984, the percentage of culls in our catch 

 was lower than in previous years due to the im- 

 plementation of the escape vent regulation. This 

 trap regulation requires that pots contain an open- 

 ing to allow sublegal-sized lobsters to escape 

 thereby reducing injuries and mortality associated 

 with overcrowded pots (Landers and Blake 1985). 

 Studies in Maine and Massachusetts by Pecci et 



Aa LOBSTERS 



2-unit Nav Size ■= 15.B33 + (0.896) Old Ska (^=0.76. nB734 

 3-Lnit Neif Sat - 13.365 + (0.927) OldX"« r^O.BO. n-253 



CARAPACE LENGTH AT TAGGING (MM) 



CARAPACE LENGTH AT TAGGING (MM) 



MALES 

 2-unrt Now Siza - 1 9.706 + (D.S42) Old Size r«0.71 . ,n-296 

 3~unJt Nov Size = 1+.623 + (0.906) Old Size r=0-e3. n=ia5 



CARAPACE LENGTH AT TAGGING (MM) 



rig. 7. Linear regressions for carapace lengths at tag- 

 ging and recapture times for all lobsters, males and 

 females for data collected during pre-operational studies 



1978-85 ( ) y = a + bx; ( ) upper and lower 95% 



C.I.; data for 3-unit studies (1986-87) represented as 

 individual points (*). 



Lobster Population Dynamics 135 



