Szedlmayer et al : Growth of age-0 Cynoscion regalis in Chesapeake Bay 



747 



25 



Q. 



5 



30n 



-25 



O 



a. 

 E 



20 



15 



U 1A 1S 10 



Date (1983) 



IN U 



U 



1A IS 

 Date (1984) 



10 IN 



Figure 2 



Salinity and temperature in Chesapeake Bay-York 

 River, VA, from all collections, 1983 and 1984. Num- 

 bers on each line refer to station anil mark data 

 points. 



expected, salinity was liighest at station 1, and de- 

 creased up the estuary. Salinity was slightly higher at 

 stations 2 through 5 in 1983 compared with 1984 (Fig. 

 2). Little difference was detected in temperature 

 among stations, except in June and July 1984, where 

 temperatures were 4-5°C warmer at the upper estuary 

 stations. Seasonally, temperature ranged 16-29°C in 

 1983, and 18-29°C in 1984 (Fig. 2). 



Weakfish catch-per-unit-effort was significantly 

 greater in 1983 than in 1984 (Table 1; Fig. 3). Seasonal- 

 ly, fish were uncommon in July samples, significantly 

 more abundant in samples taken from mid-August to 

 mid-October, but by the end of October were few in 

 number. No significant differences in catch-per-unit- 

 effort were detected among stations. Lack of replica- 

 tion in some cells (i.e., one 2-minute tow resulted in >30 

 weakfish) prevented testing for interaction effects be- 

 tween station and date. However, although not statis- 

 tically significant, there was an apparent pattern: in 

 both years fish were first abundant down estuary, and 

 as the season progressed became more abundant fur- 

 ther up the estuary (Fig. 3). 



In 1983, 845 fish were aged out of 993 collected, and 

 in 1984, 361 fish were aged out of 571 collected, by the 

 scale circuli method. An additional 98 fish were <14 

 mm SL (prior to scale formation), and ages were esti- 

 mated by applying a quadratic regi'ession of known age 

 on standard length from laboratory-reared weakfish 

 (Szedlmayer et al. In press). 



