492 
Fishery Bulletin 95(3), 1997 
been responsible for the differences in catches. The 
1-m net is an active gear, retrieved obliquely at a rate 
of about 1 m/sec through the water column, whereas 
the 1 x 2 m net is fished passively in the surface cur- 
rent (flowing 0.2-0. 5 m/sec, Warlen 2 ). Also, the mesh 
of the 1-m net is 200 m smaller and may have reduced 
extrusion of larvae. Density estimates derived from 
sampling one night per week with the 1-m net were 
similar to estimates derived from sampling every night 
per week with the 1-m net made on the same night as 
the 1 x 2 m surface net sets and further support our 
suspicions regarding the differences in sampling with 
the two gears. Finally, we have assumed for 10 years 
(Warlen 2 ) that the Pivers Island station serves as a 
proxy for Beaufort Inlet. An intensive SABRE study 
conducted in March 1996, dining which larval fish were 
sampled synchronously at seven locations in and near 
the inlet, including Pivers Island, is under analysis to 
determine how closely Pivers Island larval fish densi- 
ties reflect Beaufort Inlet densities. 
We conclude that at least one sampling event each 
week is required for estimating late autumn through 
early spring seasonal abundance of fish larvae in 
North Carolina inlets, although more frequent sam- 
pling is preferred if the standard error of estimates 
is to be reduced. Bias may be introduced by sam- 
pling only at a specific period of the lunar cycle, be- 
cause larval abundance appeared to decrease follow- 
ing spring tides. Studies where sampling is done ex- 
clusively at the same lunar phase may consistently 
over or under estimate abundance. This attribute 
may be acceptable for interannual comparisons, if 
the same methods are followed from year to year, 
but would not be acceptable for calculating the flux 
of larvae through an inlet. Sampling at intervals of 
7 days or less can reduce this bias. 
Acknowledgments 
We would like to thank L. Barker, J. Burke, M. 
Buzzell, J. Cambalik, V. Comparetta, J. Govoni, M. 
Hesik, P. Murphy, Beeda Pawlik, Brian Pawlik, R. 
Robbins, J. Scope, L. Settle, A. Walker, H. Walsh, P. 
Whitefield, and L. Wood of the Beaufort Laboratory 
who assisted with night sampling. We especially 
thank V. Comparetta and M. Buzzell for sorting, iden- 
tifying, and measuring the larvae. J. Hare and S. 
Warlen provided in-house reviews of this manuscript. 
Support for this study was received from the SABRE 
2 Warlen, S. 1996. Southeast Fish. Sci. Center, Natl. Mar. Fish. 
Serv., 101 Pivers Island Rd., Beaufort, NC 28516. Personal 
commun. 
program of the National Oceanic and Atmospheric 
Administration’s Coastal Ocean Program / Coastal 
Fisheries Ecosystems Studies. 
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