RICHARDSON: SPAWNING BIOMASS AND EARLY LIFE OF NORTHERN ANCHOVY 



JULY 1975 



A. TEMPERATURE CO AT 3m 



B. SALINITY (%o) AT 3m 



C. CHLOROPHYLL (Relotive Units) AT 3m 



46° 



44' 



42° 



128° 126° 124° 



D. PLANKTON VOLUME (mi/IOOOm') 



46° 



44c 



42' 



128° 



128° 126° 124° 



E. Engraulis mordax EGGS (No. / lOm^ ) 



128° 126° !24° 



F. Engroulis mordox LARVAE (No/IOm*) 



• • • / • 



II /19** 











LuMPOu^ 



•  *w^piveR 

 000^ 



coos 



0-OC 



128' 



126' 



124° 



128° 



Figure 3. — Results from the July 1975 ichthyoplankton survey off Oregon and Washington; hydrography, plankton volume, Engraulis 

 mordax eggs and larvae. One chlorophyll unit is equivalent to 46.3 /ng coproporphyrin standard 1 or 6.14 pig chlorophyll a 1. Mean 

 standard length of northern anchovy larvae on each transect is listed along the left margin of F. 



Eggs and Larvae 



Northern anchovy eggs were taken at 17 and 23 

 of the 70 stations sampled in 1975 and 1976 (Fig- 

 ures 3, 4; Table 2). In 1975 the center of egg abun- 



dance was north of the Columbia River plume. 

 Largest concentrations, up to 17,931 under 10 m^ 

 sea surface, occurred 120-157 km off the mouth of 

 the Columbia River. In 1976, the center of abun- 

 dance was located 83 km off the Oregon coast 



863 



