per fisherman from five different fishermen for 

 a total of 20 traps per area. Again there was 

 an exception in area 1 of Knox County where 

 we only measured the prescribed number of 

 traps from four fishermen. As a consequence, 

 we sampled a total of 256 traps in all selected 

 counties and areas. 



Certainly there are more versions in design 

 and dimension of traps than we sampled. In- 

 tuitively, I assume that those designs and mea- 

 surements approximate the sampled traps. 



The measurements on each trap included: 

 (1) the length, width, and height, (2) the lath 

 spacing on the side of the trap from the bottom 

 through the fifth lath spacing, (3) the wire hoop 

 diameter for the entrance port, and where 

 applicable, the "skate mouth" width. The 

 "skate mouth" is a knitted head in the entrance 

 port with no wire hoop. 



Also we noted if the trap in cross section 

 was square (usually trapezoidal) or half-round 

 and whether each had a parlor, and if so, the 

 number. 



Trap measurements and types from all areas 

 have the following ranges by category: 



(1) a. Length; 95% of the sampled traps 



vary from 670 to 900 mm (2.20 to 

 2.95 ft); while the remaining 5%, 

 usually with two parlors, vary from 

 1,210 to 1,250 mm (3.97 to 4.10 ft). 



b. Width; varies from 440 to 660 mm 

 (1.44 to 2.16 ft) with little demarca- 

 tion between traps of different 

 lengths. 



c. Height; the round trap, constituting 

 45% of the sampled traps, varies 

 from 360 to 410 mm (1.18 to 1.34 

 ft) ; while the square trap, comprising 

 55% of the sampled traps, varies 

 from 270 to 355 mm (0.88 to 1.16 ft). 



(2) Lath spacings; all types of traps vary 

 from 12 to 55 mm (0.47 to 2.16 inches) 

 with the narrowest measurement 

 usually at the first spacing on the 

 side nearest the bottom of the trap ; 

 the spacings thereafter are more 

 uniform. The mean lath spacing is 

 30.8 ± 0.6 mm (1.21 inches), again 

 with no demarcation as to type of 

 trap. 



(3) Hoop diameter or "skate mouth" 



width; 86% of sampled traps have 

 wire hoops in the entrance ports; 

 these hoops vary from 110 to 154 mm 

 (4.33 to 6.06 inches) with a mean 

 diameter of 128 ± 0.6 mm (5.06 

 inches). The remaining 14% of the 

 sampled traps have "skate mouths" 

 which vary in width from 118 to 

 194 mm (4.64 to 7.64 inches) with a 

 mean width of 150.6 ± 3.3 mm (5.93 

 inches). 



All of the sampled traps have parlors; usually 

 these parlors have no wire hoops in the mouth. 

 The parlors and heads are usually knitted from 

 nylon twine. In both cases the mesh sizes range 

 from 50 to 77 mm (1.97 to 3.03 inches), stretched 

 mesh, knot to knot. 



Based upon the measurements from this 

 study, we concluded that trap designs and 

 measurements vary between fishermen and 

 areas and that each fisherman may alter the 

 design from trap to trap (Table 1). At first 

 this is an alarming situation in regard to gear 

 selectivity and its possible influence on the 

 length composition of the catch. The subse- 

 quent collection and analysis of length fre- 

 quencies from the commercial catch, coupled 

 with the 10 to 15:1 throwback ratio of sublegal- 

 to legal-sized lobsters from area to area (per- 

 sonal observations), make it logical to assume 

 that most of the present-day traps have a mean 

 selection range below the minimum legal size 

 of 81-mm (approximately 3-3/16 inches) cara- 

 pace length. 



The influence of the variable measurements 

 and trap design on catch-per-unit-of-effort 

 values cannot be resolved because of the man- 

 datory sampling design for the survey of the 

 commercial fishery. There is a possibility that 

 this situation could cause some of the aber- 

 rancies in the catch and effort section. 



The trap design from the current study com- 

 pared to the description in 1948 reveals that 

 there has been a change from the "double- 

 header" to the "parlor" traps. We found that 

 the two most widely used types in cross section 

 are (1) the half-round, and (2) the square 

 (usually trapezoidal) traps. Both types usually 

 have one or two parlors. Evidently, fishermen 

 believed that parlors in traps reduce escape- 

 ment. 



