FISHERY BULLETIN: VOL. 78, NO. 3 



METHODS 



All collections of juvenile and adult northern 

 anchovies used in this study were made off the 

 Oregon-Washington coast, 1975-77 (Table 1, Fig- 

 ure 1). Because no commercial anchovy fishery 

 exists in this region our sampling for northern 

 anchovies was exploratory in nature and re- 

 stricted by available vessel and gear facilities, 

 most of which were not specifically designed for 

 efficient capture of pelagic schooling fishes. In the 

 field, fish were either frozen in plastic bags or 

 preserved in 10% Formalin.'* In the laboratory, fro- 

 zen fish (=1,400) were thawed, blotted on paper 

 towels to remove excess moisture, measured (to 

 nearest millimeter standard length, SL), and 

 weighed (to nearest 0.1 g). Fish were slit open and 

 sex and stage of gonadal development were re- 

 corded. Both otoliths were removed and placed in a 



''Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



scale envelope for later age determination. Pre- 

 served fish ( =700) were soaked in freshwater, blot- 

 ted on paper towels, measured, and weighed. The 

 paired gonads were then removed and stored in 5% 

 Formalin. These were later weighed (wet weight) 

 to the nearest 0.1 mg on a Mettler electronic bal- 

 ance. 



General gonadal condition was determined 

 using the criteria of Lagler (1956). Northern an- 

 chovies taken in March, May, and October before 

 and after the spawning season were classified as 

 immature or mature, depending on whether eggs 

 or milt were grossly apparent. Fish taken in July 

 during the spawning season were classified as 

 either immature (no eggs or milt grossly visible), 

 ripe ( gonads firm, eggs and milt distinctly visible), 

 or spent (gonads flaccid, often dark in color). Spent 

 female anchovies were further characterized by 

 the absence of oocytes in the posteriormost region 

 of each ovary. No attempt was made to distinguish 

 the spent condition in males or stages of recovery 

 after spawning in either sex. A gonadal index (GI) 



Table l. — Collection data for juvenile and adult northern anchovies, Engraulis mordax, off Oregon and Washington, 1975-77. ((Jear 

 abbreviations: ST — shrimp trawl, MST — modified shrimp trawl, IKMT — Isaacs-Kidd midwater trawl, OT — otter trawl, MOT — mod- 

 ified otter trawl, MCPT — modified Cobb pelagic trawl.) 



Sampling effort 



Date 



Gear 



No. tows 



Tow duration (mm) 



Sampling location 



Results 



7-16 Mar. 1976 12.5m MST 



18-26 July 1977 40 m MCPT 



52 



53 



36 



11 



14 



5 



5-40 



5 



10-20 



5 

 =30 



10-15 



30 



10-15 



10-20 



30 



Columbia River moutti just inside 

 north jetty and near buoy 1 



Off Columbia River mouth, buoys 

 1 and 2 



Off Columbia River mouth, light- 

 ship to North Head, between 

 lat. 46°22' and 46°10' N and 

 long. 124°22' and 124° 09' W, 

 20-91 m 



Off Columbia River mouth, 

 buoys 1 and 2 



Off Columbia River mouth, lightship 

 to North Head, inside 91 m contour 



Columbia River mouth, just inside south 

 jetty and off Gearhart, Oreg. (3.7 

 km south of mouth) 



Columbia River mouth, inside river along 

 north shore to Tongue Pt. (3.7 km from 

 mouth) and offshore between lightship 

 and North Head inside 91 m contour 



Columbia River to Coos Bay, Oreg 

 =91-183 m, on commercial shrimp 

 grounds 



Oft Columbia River mouth, 20-91 m 



= 120-140 km off Newport, Oreg. 



Between Columbia River and Tillamook 

 Bay, 120-157 km offshore 



Off Oregon- Washington coast between lat 

 47' and 43'" N and long 124°38' and 

 126° 32.8' W from= 18.5 to 175-1- km 

 offshore, trawl depth usually 15-20 m 



anchovies 



=500 anchovies, 95% juveniles, 



<100 mm SL 

 Thousands of anchovies, 50-170 



mm SL, most captured in OT 



on or near bottom in daytime 



at lat. 46° 16.6' N, long. 124°10.9' W, 



33-35 m 

 =200 anchovies, mostly juveniles, 



52-123 mm SL 

 =700 anchovies, mostly juveniles, 70-90 mm 



SL, in small schools near surface at night 



(few mature fish and none in spawning 



condition) 

 2 anchovies, <100 mm SL 



Thousands of anchovies, only juveniles 

 (60-90 mm SL) in nver near surface, botfl 

 juveniles and small adults (102-126 mm 

 SL) offshore near bottom and in midwater 



Thousands of anchovies, =70-140 mm SL — 

 most abundant between Astoria Canyon 

 and Tillamook Bay 



Thousands of anchovies, =50-170 mm SL, 

 most in midwater, greatest catches in 

 24-27 m 



31 adult anchovies, 104-134 mm SL, most in 

 spawning condition (only caught at night) 



14 adult anchovies, 108-134 mm SL, most 

 in spawning condition, small schools of fish 

 observed near surface around ship 



=640 adult anchovies, 105-147 mm 

 SL, many in spawning condition, taken only 

 at four stations north of lat. 45°41 ' N 

 between 65 and 1 20 km offshore 



604 



