FISHERY BULLETIN: VOL. 84, NO. 1 



0-age English sole in San Francisco Bay but not off 

 the coast. 



Based on the incidence of a parasitic infection, ap- 

 parently acquired only in estuaries, and the absence 

 of 0-age English sole in Demory's (1971) surveys off 

 the northern Oregon-southern Washington coast, 

 Olsen and Pratt (1973) concluded that estuaries are 

 likely the exclusive nursery for English sole on the 

 Oregon coast. Laroche and Holton (1979), however, 

 captured 0-age English sole in shallow waters along 

 the open Oregon coast, indicating that estuaries may 

 not be the only nursery area for English sole off 

 Oregon. 



The main objective of our study is to evaluate the 

 relative importance of estuarine and open coastal 

 nursery grounds for young English sole off Oregon. 



METHODS AND MATERIALS 



Bottom trawl collections provided most of the in- 

 formation on the distribution and abundance of 

 juvenile English sola Collections were made in Ya- 

 quina Bay and along the open coast outside the bay. 

 These were supplemented with extensive trawl col- 

 lections farther to the north and south along the 

 open coast and collections in other estuaries. 



Fish were collected using a 1.52 m wide, 56 cm 

 high beam trawl (see Krygier and Horton 1975) from 

 the RV Paiute and from a 7.3 m dory. Additional col- 

 lections with a 2.72 m beam trawl (Carey and Heya- 

 moto 1972) were made on the RV Cayuse. To retain 

 small, settling fish, fine-mesh (1.5-3.5 mm stretch) 

 liners were used in the trawls. The 1.52 and 2.72 m 

 beam trawls were fitted with a 1.0 or 2.0 m circum- 

 ference wheel, respectively, and a revolution counter 

 to estimate the area sampled (Carey and Heyamoto 

 1972; Krygier and Horton 1975). Tows were made 

 at 0.7-1.0 m s _1 . Tow duration was normally 5-10 

 min on the bottom in estuaries and 10-20 min along 

 the coast, usually at a 4:1 scope Most tows were dur- 

 ing daylight hours. 



Collections for juvenile English sole were made in 

 five different study areas (Fig. 1, Table 1): 



ESTUARINE 



1) Yaquina Bay: 1.52 beam trawl collections were 

 made in lower Yaquina Bay from January 1970 

 through February 1972 by Krygier and Johnson (un- 

 publ. data) and Krygier and Horton (1975) and sup- 

 plemented by collections in 1977-79. Additionally, we 

 used collections made by Myers (1980) with a 100 

 m beach seine (11.0 mm stretch mesh in the inner 

 wing and bunt (Sims and Johnsen 1974)). 



2) Other estuaries: The 1.52 m beam trawl was 



towed from a 7.3 m dory in four estuaries north and 

 south of Yaquina Bay (Tillamook and Siletz Bays, 

 107.5 and 35.2 km to the north of Yaquina Bay and 

 Alsea Bay and Umpqua River estuary, 21.3 and 105.6 

 km to the south). Each estuary was divided into 

 seven equal-area portions from which we planned to 

 take three random trawl collections (2 of the 21 

 trawls in the Umpqua River estuary were not com- 

 pleted). 



COASTAL 



3) Moolack Beach: 1.52 m beam trawl collections 

 were made on a monthly or bimonthly basis in 

 shallow (3-31 m depth) nearshore waters in a 1.0 

 km 2 area just north of Yaquina Head during 1977, 

 1978, and 1979. Moolack Beach is semiprotected by 

 headlands to the north and south and offshore by 

 a reef that rises from 15 m to 6 m. 



4) Grid stations: Collections were taken with a 

 2.72 m beam trawl, approximately monthly, during 

 1978 at 1.9, 5.6, and 9.3 km (1, 3, and 5 nmi) offshore 

 along lat. 44°41.6'N, 44°36.6'N, and 44°31.6'N. Thir- 

 teen collections were also made in this area with the 

 1.52 m beam trawl. 



Table 1.— Summary of collections used in this study. 



1 Net liners 3.5 mm and cod end liner of 1.5 mm stretch mesh, 1970-72. 

 2 Net liners 3.2 mm stretch mesh, 1977-79. 



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