FISHERY BULLETIN: VOL. 75, NO. 4 



2.5 



D 1.5 

 0.5- 

 2.5 



N 1.5 

 0.5 

 2.5; 



1.5; 

 0.5- 

 2.5 



S 1.5 

 0.5- 

 2.5; 



A 1.5- 



0.5- 



__ 2.5- 



+ j i-5- 



0.5 



o 2.5 



J 1.5 

 0.5- 



1974 



ZL 



Cn_ 



2.5 



M 1.5 

 0.5 

 2.5 



A 1.5 

 0.5- 

 2.5 



M I 5" 

 0.5- 

 2.5 



F 1.5 

 5 

 2 5- 



J '.5 

 0.5- 



r-. rs 



-dJ 



NO SAMPLE 



NO SAMPLE 



NO SAMPLE 



r"-i 



60 100 120 140 160 

 TOTAL LENGTH (mm) 



1973 



180 200 220 240 



90 HO .30 150 '70 190 



TOTA^ LENGTH n 



Size may be a determining factor for migration 

 of young croakers from the York River. From 1972 

 to 1974, length frequencies (Figure 16) indicated 

 that very few young-of-the-year croakers >130 



10 30 50 70 90 110 130 150 170 190 210 230 250 

 TOTAL LENGTH (mm ) 



FIGURE 16.— Monthly length-frequency distributions of croaker, 

 Mieropogonias undulatus, from York River, 1972-74. Modes I and 

 II, young-of-the-year; mode III, yearling. Frequencies expressed as 

 log (x + 1) at 5-mm increments. Only the lower portion of river 

 (strata A-D) is represented in 1974. 



mm TL stayed in the York River during the winter 

 months. Young-of-the-year croakers were present 

 in the York River in large numbers all year round 

 except during the summer months (June- 

 August). Young croakers showed slower growth 

 rates over winter (Figure 16). Those entering the 

 estuary between September and November were 

 the main strength of the year class ( modes I and III 

 of Figure 16). Whether they represent progeny 

 from a different spawning population compared 

 with the earlier group (mode II of Figure 16) is 

 unknown at present. 



Length frequencies of croakers taken between 

 September and November 1972-74 were pooled to 

 compare distribution by size in the York River 

 (Figure 17). The size composition indicated that 

 smaller fish were caught in the upper part of the 

 York River and saline portions of the Mattaponi 

 and Pamunkey rivers. Larger fish were propor- 

 tionally more abundant in the lower part of the 

 river. Larger fish also constituted a larger portion 

 of the croaker catch in. the channel than in the 

 shoal area (Figure 18). The 30.5-m beach seine 



676 



