FISHERY BULLETIN: VOL. 69. NO. 4 



We assumed that few or no larvae moved from 

 other estuaries into the White Oak River estuary. 



We collected larval, pre.juvenile, and juvenile 

 menhaden at 14 sampling locations extending 

 34 km upstream from Bogue Inlet (Figure 1). 

 The distance between stations varied from 2 to 

 5 km and averaged about 3 km. The type of gear 

 we used, frequency of sampling, and date of 

 sampling are listed in Table 1. 



Table 1. — The White Oak River estuary sampling 

 schedule. 



^ Stations 1, 3, 4, and 5 were sampled irregularly in this period. 

 ^ A few samples were taken upstream with the surface trawl in this 

 period. 



We sampled larvae entering the estuary at the 

 Swansboro Bridge (station 2) 2 or 3 days per 

 week from November through April in 1967-68 

 and 1968-69. During July, August, and Sep- 

 tember 1968, we sampled at several of the up- 

 stream stations. Starting in February 1969 we 

 collected menhaden throughout the river and 

 estuary, although our efforts were concentrated 

 on the upstream section (stations 6 through 12) . 

 In March and April we visited these stations 

 every week; in May, every 2 weeks; and from 

 June to September, every month. 



During the 1967-68 and 1968-69 seasons, we 

 sampled for larvae with a channel net described 

 by Lewis, Hettlei', Wilkens, and Johnson (1970). 

 The net, with a 1 by 3 m opening, had a tail bag 

 constructed of 0..5-mm mesh. At Swansboro we 

 attached the net to the bridge and made four 

 to six 30-min sets per day. At the other loca- 

 tions, we towed the net between two 16-ft alum- 

 inum boats and made a 1.5-min set when the 

 larval and i)rcju\enile menhaden were scarce and 

 a I3-miii .set when they were abundant. 



During July, August, and September 1968, we 

 sampled juveniles with a 6.1-m surface trawl 



WHITE OAK 

 RIVER 



Figure 1. — Sampling locations for young menhaden on 

 the White Oak River estuary, N.C. 



having a 6.2-mm bar mesh. We towed it in the 

 same manner as the channel net. During the 

 corresponding months in 1969, most of the col- 

 lections were made with the channel net. 



In all the collections, the number of menhaden 

 caught was expressed as an index (/ = number 

 of young menhaden per 100 m' water strained). 



We recorded surface temjjerature and salinity 

 at the start and end of each set at the bridge 

 and at the end of each tow at the other sites. 

 We measured the amount of water strained by 

 the net during each set with a flowmeter. Dis- 

 solved oxygen and turbidity readings were taken 

 only in July, August, and September 1968. 



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