FISHERY BULLETIN: VOL. 81. NO. 4 



the summer and fall (Grosslein 1969). Supplemental 

 samples were collected from May 1 980 to June 1981 

 from commercial pound net operations in Gardiner's 

 Bay, N.Y., and Sandy Hook Bay, N.J., and from a 

 trawl fishery in Delaware Bay. 



Weakfish from NMFS and Gardiner's Bay catches 

 were randomly sampled and total length (TL) to the 

 nearest millimeter (nearest centimeter for NMFS 

 samples), sex, and maturity stage were recorded 

 Scales were removed from an area midway between 

 the center of the second dorsal fin and lateral line 

 (Perlmutteretal. 1956) on25-30 fish per hauL Weak- 

 fish from Sandy Hook and Delaware Bays were sam- 

 pled by random selection of 50-lb boxes in each size 

 category available from the catch. Biological data 

 and scales were collected from the subsample. Whole 

 and gutted weights to the nearest gram were record- 

 ed for fish collected in Sandy Hook and Delaware 

 Bays. Length-frequency data for the Delaware Bay 

 fishery were collected by random sampling weakfish 

 during off-loading operations in Cape May, N.J. 



Aging Methods 



Impressions of nonregenerated scales were prepared 

 on laminated polyethylene plastic and examined with 

 a standard microfiche reader at a magnification of 32 

 times. Annuli were identified as the area of cutting 

 over circuli occurring in the proximal as well as the 

 lateral fields of the scale (Taylor 1916; Perlmutter et 

 al. 1956). Scale measurements were made from the 

 focus to each annulus in the lateral field and recorded 

 directly onto ruled cards. The data were subsequent- 

 ly stored in an IBM 4 370 computer. 



Data Analysis 



To examine variations in growth, we subdivided the 

 sampling range into geographic areas in regions and 

 estimated growth by area. The designated regions 

 were I, Delaware Bay to North; II, Chesapeake Bay; 

 and III, Cape Hatteras. Six areas were established 

 based on locations of reported spawning grounds 

 (Hildebrand and Schroeder 1928; Bigelow and 

 Schroeder 1953; Daiber 1957; Thomas 1971; 

 Merriner 1976). The designated areas were 1) Cape 

 Cod, Mass., to Block Island, R.I.; 2) Block Island to 

 Fire Island, N.Y., which encompassed Gardiner and 

 Peconic Bays; 3) Fire Island to Great Bay, N.J.; 4) 

 Great Bay to Ocean City, Md., which includes 

 Delaware Bay; 5) Ocean City to Virginia Beach, Va., 



which includes Chesapeake Bay; and 6) Virginia 

 Beach to Cape Fear, N.C. (Fig. 1). 



Back- calculated lengths at age of individual fish 

 were calculated from scale annulus measurements 

 using a fish TL-scale size regression equation. 

 Individual scale measurements were adjusted 

 according to average scale size for each fish length to 

 reduce the variance in scale size created by scale 

 samples not being removed from exactly the same 

 location on each fish (Ricker 1975). Von Bertalanffy 

 growth curves were fit to mean back- calculated 

 lengths at age (weighted by n) using a nonlinear 

 regression program available in the Statistical 

 Analysis System (Helwig and Council 1979). High 

 correlations between L„ and K invalidated univariate 



200 m 



4 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



FIGURE 1.— Map of Middle Atlantic region showing stratification 

 into three regions (I- III) and six sampling areas (1 - Cape Cod, Mass., 

 to Block Island, R.I.; 2 - Block Island to Fire Island, N.Y.; 3 - Fire 

 Island to Great Bay, N.J.; 4 - Great Bay to Ocean City, Md.; 5 - Ocean 

 City to Virginia Beach, Va.). 



804 



