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mum larval abundance in the Bering Sea occurs in May 
(Duffy-Anderson et al., 2010) and probably reflects peak 
hatching of eggs spawned in April and a relatively high 
degree of spawning synchrony. 
The geographic sampling area over which these eggs 
were collected was small compared to the potential 
spawning area over the Bering Sea continental shelf, 
and available evidence indicates that Alaska plaice do 
spawn over a large portion of the middle domain of the 
continental shelf (Zhang et al., 1998). The wind-mixed 
layer in the Bering Sea generally extends to 25-30 m 
in spring (Stabeno et al., 2001), and our data reveal 
that Alaska plaice eggs primarily occur above or within 
this layer. As such, the eggs are vulnerable to the sto- 
chastic effects of wind activity, which could disperse 
them widely over the shelf, especially in early spring 
months ( March-April) when the likelihood of storm 
events is high. However, prevailing winds over the shelf 
in late spring-summer are southwesterly and would 
therefore transport late-stage eggs and newly hatched 
larvae from the middle shelf toward nursery areas 
along the Alaska mainland coast. Indeed, previous work 
has shown that Alaska plaice larvae are relatively rare 
over the continental shelf (Bailey et al., 2003), lending 
credence to the idea of shoreward transport of older 
egg stages and hatched larvae. It should be noted that 
retention in near-surface layers is also likely to promote 
faster rates of egg development because temperatures in 
the upper water column are 1— 3°C warmer than those 
at depth over the middle shelf during spring. 
Alaska plaice eggs do occur in near-surface waters, 
making them accessible to CUFES system, but many 
eggs also occur below the depths sampled with the 
CUFES. Therefore, abundance determined from eggs 
caught with the CUFES system may be underestimat- 
ed- — particularly the abundance of early stages that 
might be deeper in the water column. This observation 
has been made elsewhere (Lo et al., 2001; Dopolo et 
al., 2005), and at least in the case of Alaska plaice, we 
recommend that sampling with the CUFES system be 
supplemented with sampling of the entire water column 
to ensure adequate sampling of eggs at all stages of 
development. Moreover, sampling earlier in the spring, 
in March-April, for earlier stages is encouraged. 
Acknowledgments 
Thanks to the officers and crew of the NOAA ship RV 
Miller Freeman. Comments by T. Smart, C. Jump, J. 
Napp, and three anonymous reviewers improved the 
manuscript. Funds were provided by the North Pacific 
