< 



Q 

 > 



O 



or. 



M:F=|:0.99 



%BF=6.7 



1975 

 N = I047 



r^fTl 



X = 64.219.9 

 %L = 4.5 



00- 

























M:F=|:I.07 



%BF = 5.9 



00- 



1976 

 N=596 













X = 73.6t 7.0 



%L= 13 6 





—n — i — i — i — 



, r^if 













] 



In,,,, 



1977 

 N = 549 



M.-F= |:0.92 

 %BF=3.7 



X = 76.6S 6.6 

 %L=I5.7 



, f~T 



68 64 70 76 82 88 94 



CARAPACE LENGTH (mm) 



Figure 4. — Annual size distribution of lobsters in the Millstone Point area. 

 1975-77 (wood pots). Values for male:female sex ratios (M:F), percent of berried 

 females ( r t> BF>, mean carapace length (X), and percent legal catch ( r oLl are also 

 presented. 



pots (2.5 cm 2 mesh) in Block Island Sound (BIS), calculated an 

 average CL of 74 mm. 



The percent of legal-sized (CL > 81 mm) individuals in our 

 catch ranged from 7.2 to 18.1% (1976-81). The values reported by 

 other area investigators range between 16.7 and 34.0% (Smith 

 footnote 4; Briggs and Mushacke 1979; Marcello et al. footnote 7). 

 Over 92% of the legal-sized lobsters in our study were newly 

 recruited from the sub-legal class (assuming 13% growth per 

 molt). 



Our study area has a higher proportion of small lobsters and a 

 smaller proportion of legal-sized individuals than has been 

 reported from surrounding areas. Over 75% of the legal-sized in- 

 dividuals that we tagged and released were subsequently caught by 

 commercial fishermen, and removed from the population. These 

 data attest to the high exploitation of the local lobster population, 

 especially in the summer when recreational fishing increases. 

 Availability of shelters and physical habitat characteristics appear 

 to be the primary naturally occuring limiting factors (excluding the 

 physical parameters of temperature, salinity, and oxygen) of 

 lobster populations (Phillips et al. 1980). 



Sex Ratios 



Since 1975, the yearly mean sex ratio of males to females was 

 close to 1:1 (Figs. 4, 5). However, when three stations were com- 

 pared, Twotree had consistently higher proportions of females, 

 whereas Intake and Jordan Cove had slightly more males. Sex 

 ratios close to 1 : 1 were also reported by other researchers working 

 in nearshore waters (Herrick 1909; Templeman 1936; Ennis 1971, 

 1974; Stewart 1972; Krouse 1973; Thomas 1973; Cooper et al. 

 1975; Briggs and Mushacke 1980). However, Smith (footnote 4), 

 working in four different areas of LIS, found male to female ratios 

 ranging from 1 : 1 .06 to 1:1.81. Dominance of females in the catch 



600 

 50 O- 



46 52 58 6J 70 76 82 



ZOO 

 500- 



^U 



lOO ,06 112 



JJ-H" 



'-r-liT 



46 52 58 64 70 76 82 



Tl-t-r-n , . 



**tTJ 





tP~~ 



94 I0O lOG H2 



Figure 5. — Annual size distribution of lobsters in (he Millstone Point 

 area caught in wood and wire pols, 1978-81. Values of male:femaie 

 sex ratios (M:F) and percent of berried females (%BF) represent 

 combined pot type data. Mean carapace length (X) and percent legal 

 catch C7oL) values are presented for each pot type. 



