54« 



34° 132° 130 



^Langara I. 

 <4j 



I28°W 



\ZS° 



FISHERY BULLETIN; VOL. 85, NO. 3 

 124° 122° 



52°N 



50° 



48< 



Cape St James 



5I°N-I3I°W 



PACIFIC OCEAN 



54° 



52°N 



Koins 



50° 



Amphi 



trite Pt-* I 



48° 



134° 



132° 



130° 



I28°W 



126° 



124° 



1220 



FiC.URE 6. — Locations where environmental conditions were monitored for regression analysis 

 with sockeye salmon migratory patterns: sea surface temperature and salinity at Amphitrite 

 Point. Kains Island, Cape St. James, and Langara Island; sea level at Tofino; Ekman transport 

 at lat. SIN, long. ISl'^W; and Fraser River discharge at Hope. 



of the extent of warm water intrusion from the 

 south along the coast. 



2) Sea surface temperatures (average April- 

 June) at ocean station P (50 N, 145°W) (see Fig- 

 ure 8) (S. Tabata'') as an indication of ocean condi- 

 tions in the Gulf of Alaska. After sampling at this 

 station was terminated in 1981, temperatures for 

 this area in the Pacific Ocean were obtained from 

 satellite and shipboard observations. 



3) Monthly mean sea-levels (average April- 

 June) recorded at Tofino, on the west coast of 

 Vancouver Island (Fig. 6), as an indication of con- 

 vergent and divergent conditions along the coast 

 (A. Dodimead^). Also, high coastal sea levels indi- 

 cate northward currents. 



4) Ekman transport normal to the coast (aver- 

 age April-June) at 5rN, 131°W (Fig. 6) calcu- 

 lated from barometric pressure data (Dodimead 



6S. Tabata, Institute of Ocean Sciences, Patricia Bay, B.C. 

 V8L 4B2, Canada, pers. commun. 1985. 



■'A. Dodimead, Pacific Biological Station, Nanaimo, B.C. V9R 

 5K6, Canada, pers. commun. 1984. 



1984; Giovando fn. 5) to indicate the general pat- 

 tern of circulation from wind-driven transport. 



5) Fraser River discharge (average April- 

 June) measured at Hope (Fig. 6) (LeBlond et al. 

 1983; Inland Waters Directorate^), as an indica- 

 tion of coastal run-off and extent of Fraser River 

 homewater along nearshore areas. 



Linear regression analysis of Fraser sockeye 

 diversion rates from 1953 to 1985 with SST of 

 lighthouse data from Amphitrite Point, Kains Is- 

 land, Cape St. James, and Langara Island for the 

 months of April to June showed significant corre- 

 lations (Table 1). Since the correlation coefficient 

 of diversion rates was highest with the data from 

 the Kains Island lighthouse, these were selected 

 for further analysis and averaged over April, 

 May, and June. 



Regression analysis between the northern di- 

 version rates and the environmental variables 



**Inland Waters Directorate, 1001 West Pender Street, Van- 

 couver, B.C. V6E 2M9, Canada, 1985. 



462 



