PEARCY and MYERS: LARVAL FISHES OF YAQUINA BAY 



Table 4, — Average number of larvae per lO-'nv' filtered in bongo nets (mesh 0.233 and 

 0.571 mm combined) calculated from total number of specimens collected ^ total volume 

 filtered for entire year. Only species represented by five or more larvae are listed. June 

 1%9-June 1970. 



eggs within the bay, is peculiar since Richard- 

 son (1973) reported that anchovy larvae were 

 abundant well offshore, usually in Columbia 

 River plume waters, and not near the coast. 



Pacific Herring 



Abundance 



Herring larvae were abundant at all five 

 stations during February and March 1970 (Fig- 

 ure 5). A peak in catches occurred in late 

 January at the three stations closest to the 

 ocean, and conversely, higher numbers occurred 

 later (April and May) at the upper estuarine 

 stations. These trends suggest earlier spawning 

 near the mouth and later spawning in the upper 

 estuary. Based on intertidal surveys, Steinfeld 

 (1972) found herring eggs near the mouth from 

 February 5 to 20, 1970, and in the upper estuary 

 above Buoy 21 from March 8 to 24. 1970. The 

 trend for earlier spawning near the mouth of 



the estuary was therefore found in both larval 

 and egg surveys. However, the fact that Stein- 

 feld did not find any spawn before February 5 

 while we collected many larvae between January 

 23 and February 10 indicates that intertidal 

 surveys may miss substantial areas of eggs, 

 perhaps from subtidal spawning. 



Comparison of Nets 



Catches of herring larvae in the three types of 

 nets (CB and bongo with 0.233 mm mesh and 

 bongo with 0.571 mm mesh) were usually sim- 

 ilar on a m'^ basis, especially at high densities 

 of larvae (Figure 5). The type of net catching 

 the highest or the lowest number of larvae 

 altei'nated among tows. We had not expected 

 catches by the CB to compare favorably with 

 the bongo in view of the known avoidance 

 capability of Atlantic herring larvae (Bridger, 

 1956; Tibboetal., 1958). 



The percentage of herring larvae of different 



207 



