164 



Fishery Bulletin 98(1) 



age truncation of the population by directed fishing 

 effort. However, Dovel and Berggren ( 1983) reported 

 difficulty in aging fish greater than 153 cm TL and 

 may have misidentified annuli in both juveniles and 

 adults. Greeley's (1937) study was based on enumer- 

 ating annuli in otoliths. Likewise, K estimates from 

 our study are higher than those estimated previ- 

 ously. Our growth estimates are consistent, however, 

 with those of Doroshov et al.,^ who aged the same 

 population in the early 1990s. 



Comparative studies of fish populations along a 

 latitudinal gradient have shown an inverse relation 

 between latitude and rates of growth and mortality 

 (e.g. Leggett and Carscadden, 1978; Jennings and 

 Beverton, 1991). Among Atlantic sturgeon popu- 

 lations, the most rapid growth was exhibited by 

 fish sampled in southern latitudes. Maximum size 

 increased with increasing latitude, which may indi- 

 cate postponement of maturation (Magnin, 1964). 

 Values of Jf*L for the Hudson River population did not 

 differ significantly from those for any other popula- 

 tion (a=0.05), whereas L„ values estimated for the 

 Hudson River population were statistically differ- 

 ent from those estimated for all other populations 

 (a=0.05) along a latitudinal gradient (Table 2). 



Implications for stock restoration 



Growth rates of acipenserid species are apparently 

 affected by migratory behavior (Roff, 1988). Anad- 

 romous species of sturgeons exhibit higher growth 

 coefficients than do semi-anadromous or freshwater 

 resident species, although the semi-anadromous 



Table 2 



Growth parameters have been calculated in various stud- 

 ies of Atlantic sturgeon populations (combined sexes). For 

 Smith (1985), n=number of age classes. Smith's (1985) 

 data were converted from fork length to total length (FL= 

 111- TL; Beamesderfer, 1993 ) and were presented as mean 

 length by age class in the literature. 



Location 



Study 



K ijcml 



St. Lawrence River Magnm, 1964 582 0.03 315 



Kennebec. ME 

 Hudson River, NY 

 Winyah Bay, SC 

 Suwannee River, FLA 



Smith, 1985 

 This study 

 Smith, 1985 

 Smith, 1985 



7 0.06 236 



634 0.08 225 



24 0.12 242 



17 0.14 184 



white sturgeon achieves a higher maximum length 

 than do anadromous sturgeons (Table 3). Atlantic 

 sturgeon undergo an ontogenetic habitat shift from 

 estuarine nursery grounds to marine waters (Gil- 

 bert, 1989). We believe these species grow rapidly 

 as juveniles (as shown by their high /f coefficient) to 

 outgrow predation in marine waters. Unfortunately, 

 rapid gi-owth may affect the timing of juvenile migra- 

 tion and increase their susceptibility to coastal fish- 

 eries at an early age. 



Estimates of growth traits for Hudson River Atlan- 

 tic sturgeon indicate that they are extremely vulner- 

 able to overfishing. Slow growth following matura- 

 tion, high longevity, and presumed low natural mor- 

 tality indicate that year classes in this population 

 reach their maximum biomass at relatively old ages 

 (Alverson and Carney, 1975). Therefore, maximum 

 fishing yield from sturgeon would be achieved at low 



