FISHERY BULLETIN: VOL. 81, NO 3 



larval survival in the field. Finally, an attempt was 

 made to examine the contribution of year-to-year 

 variation in ocean conditions during the postspawn- 

 ing season to variation in year class strength. Ocean 

 conditions were primarily characterized by Bakun's 

 upwelling indices. 



MATERIALS AND METHODS 



Sampling for Pandalus jordani larvae was carried 

 out during 32 cruises from January 1971 to August 

 1972 along a transect extending 60 nmi from the 

 coast off Newport, Oreg., U.S.A. (Newport Hydro- 

 line; stations designated NH-1, etc. according to dis- 

 tance from coast; Fig. 1). Sampling was at 

 approximately fortnightly intervals (Fig. 2). On all 

 but one cruise the 24.4 m RV Cayuse was used. In 

 March and April 1972 a more extensive grid sam- 

 pling was conducted on two cruises along a series of 

 seven transects from Tillamook Head (I, Fig. 1) south 

 almost to the Siuslaw River (VII) . These transects ex- 

 tended 30 mi from the coast. 



Temperature and a salinity sample were taken at 

 the surface at each station, and temperatures at lower 

 depths were obtained by bathythermograph (BT) 

 cast to the bottom or a maximum of 150 m. Bottom 

 salinity was obtained from a bottle sample collected 

 at the greatest extent of the BT cast. On 9 of the 1 1 

 cruises in 1972 (C7205D and C7207E excluded), 

 drift bottles were released. Plankton was collected by 

 stepped oblique tows to near the bottom or to a max- 

 imum of 150 m with a 0.7 m diameter bongo net 

 (cylinder-cone nets 5.1 m long of 0.571 mm Nitex 3 

 with effective filtering area to mouth area ratio of 

 8:1). The tows with three to five steps lasted 10 to 25 

 min, depending on depth. At towing speeds of 2 to 3 

 kn the nets filtered 600 to 1 ,000 m 3 ; specific amounts 

 were determined from TSK flowmeters in the mouth 

 of each net. Depths were maintained by a 40 kg kite- 

 otter depressor (Colton 1959) and recorded by time- 

 depth recorder. Samples were preserved at sea with 

 formaldehyde. Only the port side sample was 

 analyzed from each pair, a total of 367 from the two 

 years. Because of their relatively low density, the en- 

 tire sample was sorted for shrimp larvae. 



The National Weather Service gathers hourly wind 

 data at a recording anemometer located at the base of 

 the south jetty at Newport, Oreg. We used this data 

 in their stored form (north-south and east-west vec- 

 tor components; m/s) to generate progressive 

 vector diagrams. 



-44' 



-i—i  '   



NH . 1 —  Y \ i i I I 1 11 ^Yaquina Head 



(Newport) 



VI i I I i I I l/'<- n 



; Cape Perpetua 



VII,. 



1 1 i i i  i u/;'/" . 



t Cape Lookout 



Pacific 

 Ocean 



N 



-43°N 



k 



126° 



l 



126° 



i__ 



44"- 



30n.mi. 



43- 



Cape Blanco 



60 k 



m. 



123 W 



'Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



Figure 1. — Sampling transects off the Oregon coast. Newport 

 Hydro (NH) line with stations: 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 50, 

 and 60 nmi from the coast. Transects I- VII with stations 1, 5, 10, 15, 

 20, 25, and 30 nmi from coast. Transect V and NH line overlap. 



RESULTS 



Seasonal Wind, Current, and 

 Temperature Regimes, 1971 and 1972 



Progressive vector diagrams for wind from January 

 through July in 1971 and 1972 (Fig. 3) show that the 

 two years differed in several respects. In February 

 1971 winds were mixed, while in 1972 the southwest 

 winds typical of winter were consistent. Southwest 

 winds dominated in March 1971, except for a spell of 

 northwest wind from the 15th to the 21st. March 

 winds in 1972 were mostly from the southwest, but 

 less intense. There were a few 1-d reversals to 

 northwest wind. April in both years was transitional, 

 and a short spell of northwest wind initiated the up- 

 welling season. Winds of the upwelling season, May 

 through August, were stronger in 1972 than in 

 1971. 



Comparison of upwelling indices for 1971 and 1972 

 with the 25-yr average for 1946-7 1 puts them in long- 



456 



