their interface, particularly farther seaward during ebb 

 tide when current velocities were reduced. Mixing 

 between water masses also took place during flood tide, 

 but Kvichak River water was predominant along the 

 northwest shore and Naknek River water along the 

 southeast shore of Kvichak Bay. 



River runoff in this area moved southwest toward the 

 northwest side of inner Bristol Bay (Fig. 7). By the time 

 these waters had moved seaward as far as the Middle 

 Bluff area, they were more than 8 km offshore. This 

 movement of less saline water may be inferred also from 

 the salinity distribution (Figs. 3, 6). 



The course and distribution of Egegik River water is 

 also clearly seen in the salinity distribution off the en- 

 trance to Egegik Bay (Figs. 3, 4). Salinity data were not 

 obtained from the entrance of Ugashik Bay, but dye 

 studies showed that the salinity pattern there should be 

 similar to the one off Egegik Bay. 



Plotting River Waters From Drift Cards 



The drift card used in this study was developed by 

 Martin (1967). It is made of a folded sheet (22 X 28 cm) 

 of international orange plastic. A polystyrene float at- 

 tached by galvanized staples to one end and a lead 

 weight attached to the opposite end keep the card ver- 

 tical in the water. The cards are serially numbered and 

 bear printed instructions to the finder and spaces for 

 recording requested recovery information. 



On 2 June 1967, 1,007 cards were released at eight 

 locations along the northeast side of inner Bristol Bay 

 (Table 1). They were released in groups of 10 from an air- 

 craft between 1 and 2 h after high slack tide so that those 

 released near river mouths and bay entrances would 

 move immediately out into the bay. 



Cards were recovered in two ways: 1) I collected cards 

 from beaches during aerial surveys conducted 6 wk or 

 more after the cards were released, and 2) commercial 

 salmon gill net fishermen returned cards which drifted 

 into their area of operation. Of the 1,007 cards released, 

 141 were recovered (Table 1). The locations of recovery 

 and resultant directions of drift are shown in Figures 9 to 

 16. Eighty-nine (8.8%) cards were recovered from 

 beaches; parts of 31 more cards were also found on 



Table 1. — Number and percent of drift curds recovered from releases 

 in eight areas of inner Bristol Bay, 2 June 1967. 







Cards recovered 



Release location 



No. cards 







(Figs. 9-16) 



released 



Number 



Percent 



Kvichak River mouth 



102 



33 



32.4 



Naknek River mouth 



100 



44 



44.0 



Cape Chichagof 



150 



11 



7.3 



Egegik Bay entrance 



101 



5 



4.9 



Lat.58°N T 



152 



14 



9.2 



Cape Greig 



151 



21 



13.9 



Ugashik Bay entrance 



101 



4 



4.0 



Cape Menshikof 



150 



9 



6.0 



Total 



1,007 



141 



14 



Figure 9. — Recovery locations of drift cards released across Kvichak 

 River mouth, inner Bristol Bay, 2 June 1967. (Lines, from release site 

 to recovery location indicate resultant direction of drift.) 



beaches but were unusable because they had lost iden- 

 tifying serial numbers. 



The direction of drift for cards released across the 

 mouths of the Kvichak and Naknek rivers (Figs. 9, 10) 

 was seaward in a southwesterly direction. Most cards 

 recovered from these two releases were found between 

 Naknek River mouth and Johnston Hill. The concen- 



Figure 10.— Recovery locations of drift cards released across Nak- 

 nek River mouth, inner Bristol Bay, 2 June 1967. (Lines from release 

 site to recovery location indicate resultant direction of drift.) 



