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Fishery Bulletin 92(2), 1994 



sity (Fig. 3). Relative abundance of larvae also var- 

 ied among years (Fig. 2). The sum of weekly densi- 

 ties for individual sampling years differed by more than 

 an order of magnitude (Table 2). Lowest relative abun- 

 dances were observed for the last three sampling years. 

 I assumed that larval Atlantic menhaden caught 

 each week were newly recruited to the estuary and 

 that they were in transit past Pivers Island to upper 

 portions of the estuary. These assumptions are sup- 

 ported by the presence of an abundance mode on 19 

 December 1985 (Fig. 2) and the presence of similar 

 modes from bongo net sampling in the same estuary 

 one-week later about 6 km up-estuary and two-weeks 

 later about 11 km up-estuary (Warlen, unpubl. data). 

 Also, the generally narrow 95% confidence limits in 

 the age of larvae within each collection, along with 

 no increase in the confidence limits through the re- 



cruitment year (Fig. 4), does not suggest an increase 

 in the number of different birthweek cohorts in the 

 lower estuary. In a number of cases, the week follow- 

 ing a peak in density showed relatively low recruit- 

 ment (Fig. 2), a pattern that did not suggest sub- 

 stantial carryover and accumulation of larvae from 

 week to week. While a single sampling location may 

 not reflect patterns of larval estuarine recruitment 

 for all areas south of Cape Hatteras, it does provide 

 a time-series description of relative larval recruitment 

 abundances over several years inside a large inlet near 

 the presumed major fall/winter spawning area. 



Age and size of larvae 



In every sampling year the age of larvae increased 

 linearly throughout estuarine recruitment until 

 about the end of March after which 

 the mean age declined (Fig. 4). 

 Linear regressions of the mean es- 

 timated age over time, excluding 

 the end-of-season down trending 

 values, were significant (ANOVA, 

 P<0.001) for each recruitment 

 year. Young larvae were always 

 collected early in each recruitment 

 year (Fig. 4). Virtually all larvae 

 collected in November were less 

 than 40 days old. Larvae collected 

 about late March were 2—b times 

 older than larvae collected early in 

 the recruitment year. Except in a 

 few cases, the within-sample age 

 variation was small and the 95% 

 confidence limits were within ±5 

 days of the mean age. 



Larvae recruited to the estuary 

 during peak recruitment were also 

 the older larvae. Peak recruitment 

 densities were in February -April 

 (Fig. 2) and those larvae were 

 older, generally age 60-90 days or 

 older, as in 1987-88 when some 

 were up to age 115 days (Fig. 4). 

 The recruitment-year mean age of 

 larvae varied between 55 and 74 

 days for the seven years. The mean 

 age of larvae over all years was 61 

 days. 



The standard length of larvae 

 also increased significantly 

 (ANOVA, P<0.001) within each re- 

 cruitment year. The mean size of 

 larvae increased to the end of 

 March then decreased slightly to 



