Hatfield and Cadrin: Geographic and temporal patterns in size and maturity of Loligo pcaleii 201 



44"N 



42" 



40° 



38° 



1983; Lange''; Lange et al.''). Recent advances in 

 the use of statoliths for age determination of squid 

 (see reviews in Rodhouse and Hatfield, 1990; Jereb 

 et al., 1991; Jackson, 1994) have enabled now esti- 

 mates of life span to be derived for L. pcaleii ( Macy, 

 1995; Brodziak and Macy, 1996; Macy"*), which in- 

 dicate that the life span of L. pealeii can be less 

 than nine months. Back-calculations of hatching 

 date from age data revealed that there is more 

 than just a spring-summer spawning component 

 of the population (Brodziak and Macy, 1996; Ma- 

 cy''), with a small proportion of squid hatching dur- 

 ing winter This winter spawning is presumed to 

 occur offshore (Brodziak and Macy, 1996), in the 

 vicinity of the submarine canyons along the edge 

 of the northeastern U.S. continental shelf, from 

 Hudson Canyon up to Georges Bank (Fig. 1). The 

 possibility of winter spawning was raised initially 

 by Summers ( 1969), based on length-frequency da- 

 ta, but squid were not presumed to spawn until 

 their second year because their growth was as- 

 sumed to be too slow to allow spawning during 

 their first summer 



Our study reports on two studies: 1) an analy- 

 sis of survey data from spring and autumn NEFSC 

 surveys from 1967 to 1998, and from winter NEF- 

 SC surveys from 1992 to 1998, to describe gi-oss 

 distribution patterns of L. pealeii over the north- 

 west Atlantic continental shelf from Cape Hat- 

 teras to the Gulf of Maine; 2) some results of a field 

 study initiated in 1997 to investigate geographic 

 and seasonal patterns of growth and maturity to 

 determine if the winter spawning component off 

 the northeastern United States can be defined by 

 time and area. 



Materials and methods 



Survey analysis 



Length-frequency data for L. pealeii were analyzed from 

 NEFSC bottom-trawl surveys conducted in the autumn 

 (generally from mid-September to late October) from 1967 

 to 1997; in the spring (generally from March to early April) 

 from 1968 to 1998; and in the winter (generally in Febru- 

 ary) from 1992 to 1998. Data collection and processing and 

 archiving methods are described by Azarovitz (1981). In 



66'W 



36 



/y Hudson 

 Canyon 



r/ 



MAB 



MAB - Mi(d-Atlantic Bight 

 NE - New Englatitj 

 GOM - Gulf of Maifie 



/Cape Hatteras 



Ja i—i , I , L_ 



J , I I I . L 



3 Lange, A. M. T. 1984. An assessment of the long-finned squid 

 resource ofFthe northeastern United States. Northeast Fisher- 

 ies Science Center (NEFSC) Lab. Ref Doc. 84-.37. 24 p. [Avail- 

 able from NEFSC, 166 Water St. Woods Hole, MA 02543.] 



'' Lange, A. M. T, M. P. Sissenwine, and E. D. Anderson. 1984. 

 Yield analysis of long-finned squid, Loligo pealei (LeSueur). 

 Northwest Atlantic Fisheries Organization (NAFO) SCR Doc. 

 84/1X/97, 29 p. 



^ Macy W. K. 1995. Recruitment of long-finned squid in New- 

 England (USA) waters. ICES CM 1995/K:35, 18 p. [Available 

 from W. K. Macy, Graduate School of Oceanography, Univ. Rhode 

 Island, South Ferry Road, Narragansett, RI 02882]. 



Figure 1 



Map of the survey areas for longfin inshore squid off the northeastern 

 coast of the United States 1 1967-98). 



the autumn and spring sui-veys the same trawl-sampling 

 gear (Yankee-36 trawl) has been used since 1967, except 

 during 1973-81, when a Yankee-41 (high rising) trawl was 

 substituted in the spring surveys. In the winter sui-veys 

 the trawl gear was larger and the Gulf of Maine was not 

 sampled. 



The NEFSC sui-vey area was divided into two geograph- 

 ic regions (the region north of Hudson Canyon to the Gulf 

 of Maine [designated New England, NE] and the region 

 south of Hudson Canyon to Cape Hatteras (designated 

 Mid-Atlantic Bight [MAB]) and into four bottom depth 

 zones (27-55 m, 56-110 m, 111-185 m, and 186-366 m 

 [Fig. 1] ). The 1-26 m depth zone was not sampled in NEF- 

 SC offshore surveys, but "inshore" strata were added to 

 the survey in 1972. 



For the spring and winter surveys, the combined effects 

 of annual abundance (numbers of squid per standardized 

 trawl haul), survey stratum, and time of day (night, 

 20:00-03:59; dawn and dusk, 04:00-07:59, 16:00-19:59; 

 and day, 08:00-15:59), as described by Brodziak and Hen- 

 drickson (1999) for the autumn survey, were analyzed to 

 determine adjustment factors for diel differences in log- 

 transformed survey catches of prerecruit squid (<80 mm 

 dorsal mantle length [ML], the minimum size in com- 

 mercial catches) and recruits (>80 mm ML). The derived 

 factors were then used to adjust all survey catches to 



