Table 3.— Monthly catch per unit effort 

 (catch/100 pots hauled) for wood and wire pots 

 from 1978 to 1981 at Millstone Point. 





Total 



catch 



Legal catch 





Wood 



Wire 



Wood 



Wire 









1978 





August 



55 



215 



8 



18 



September 



96 



177 



14 



19 



October 



54 



132 



8 



15 



November 



98 



162 



16 

 1979 



12 



May 



86 



132 



6 



6 



June 



103 



183 



18 



15 



July 



124 



195 



23 



25 



August 



95 



164 



15 



12 



September 



69 



151 



10 



9 



October 



55 



112 



9 

 1980 



9 



May 



79 



180 



15 



15 



June 



65 



170 



14 



12 



July 



69 



177 



18 



17 



August 



56 



131 



13 



12 



September 



69 



84 



12 



8 



October 



78 



74 



6 

 1981 



3 



May 



118 



134 



8 



8 



June 



153 



116 



15 



8 



July 



157 



124 



21 



13 



August 



122 



100 



13 



11 



September 



122 



73 



11 



10 



October 



112 



66 



13 



9 



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MAY JUNE JULY AUG. SEPT. OCT. 



MONTH 



1981 had a slightly different parlor entry funnel than those used in 

 previous years, and apparently did not trap lobsters as effectively. 

 An experiment to test this is underway; preliminary data indicate 

 that slight changes in parlor head design can greatly affect trap effi- 

 ciency. Similarly, Spurr (1972) 6 reported that the principal factor 

 affecting pot efficiency was parlor head design, and Thomas 

 (1959) found that the high-rigged heads deterred escape. 



'Spurr, E. W. 1972. Lobster research project: Final report of 3-105-R, July 

 1969-June 1971. N.H. Fish Game Dep., Fish. Div., Concord, N.H., 22 p. 



^-\_ 



V 



y 



S\ 



\ 



x 



/"v.. 



\ 



S O X D 



Figure 2. — Monthly lobster catch per unit effort (per 100 pot hauls) for wood 

 pots 1976-81. 



Figure 3. — Catch per unit effort (open circles) (per 100 pot hauls) and bottom 

 water temperature (solid circles) for each station based on 1979 data. 



Size Frequencies 



The yearly size distributions of lobsters caught in the Millstone 

 Point area from 1975 to 1981 are presented in Figures 4 and 5. The 

 relatively larger proportion of smaller sized individuals in 1975 was 

 attributed to sampling methodology. During 1975, lobsters were 

 acquired from artificial habitats using scuba, from fish trawls, and 

 from impingement studies at Units 1 and 2 intake structures. 

 Subsequently, lobsters were captured using commercial pots, 

 which do not sample small individuals as effectively. Pecci et al. 

 (1978) reported that lobsters in surface-hauled pot catches were 

 larger than ones caught by divers. 



Since lobsters have been collected using wood pots, yearly mean 

 carapace length and percent legal catch have not varied greatly. 

 From 1976 to 1981, average CL ranged from 73.3 to 76.6mm. Two 

 other investigations within LIS that used wood pots found larger 

 lobsters: mean CL of 78.9 mm was reported by Smith (footnote 4) 

 for an area east of the Connecticut River, and 78.2 mm was 

 reported for western LIS (Briggs and Mushacke 1979). Our study 

 also used wire pots since 1978, and yearly mean CL for these traps 

 ranged from 70.9 to 71.5 mm. Marcello et al. (1979)', using wire 



'Marcello, R. A., Jr., W. Davis 111, T. O'Hara, and J. Hartley. 1979. Popula- 

 tion statistics and commercial catch rate of American lobster (Homarus 

 americanus) in the Charlestown-Matunuck, Rhode Island region of Block Island 

 Sound. Submitted to New England Power Company, YAEC1 175, 40 p. Yankee 

 Atomic Electric Company, 20 Turnpike Road, Westboro, MA 01581. 



