730 



Fishery Bulletin 90(4), 1992 



The fourth fish was captured at the southern high spot of 

 Heceta Bank (80 m depth, same date and capture site as 

 Fishes 2 and 3) and released 27min after capture l.Snmi off- 

 shore in a habitat where yellowtail rockfish were rarely 

 seen— where the bottom was 150 m, flat, and comprised of 

 fine sediments. Between 1727h on 7 September and 0730h 

 the next day, this fish was tracked continuously (Fig. 3). It 

 moved to the northeast until 0400 h, turned south, but then 

 resumed its northeasterly course, ending up near the 75 m 

 depth contour just west of a shallow region of the bank, about 

 2nmi from its capture location. 



1 989 (Fig. 4) Two experiments were conducted in 1989 to 

 further investigate horizontal movements: one involved 

 three fish caught and released with pressure-telemetering 

 transmitters at a station on 21 August (1 fish) and 24 Aug- 

 ust 24 (2 fish). The other experiment included six fish, three 

 of which were released at the capture site and three displaced 

 1.1 miles away, on 25 August. All fish were caught in mid- 

 water at ~79m. 



Fish 2 in the first experiment was released at site A and 

 was tracked continuously for 11 h after release. During this 

 time it stayed within ~0.2nmi of the release site, which was 

 marked by a surface buoy. We returned to this location 36 h 

 later and found this fish 0.5nmi to the east. After 1.5h it 

 returned to the release site and was located several times 

 in this vicinity during the next 56 h (Fig. 4). 



Two other fish were caught, tagged, and released 3 days 

 later, at site B, and tracked for about 24 h. Acoustical signals 

 of these two fish stayed within 0.2 nmi of the release loca- 

 tion during this period. 



In the second experiment, six fish were caught at site B 

 on 25 August. Three fish (10, 11, 12) were released at the 

 capture location and three (7, 8, 9) were displaced 1.1 nmi 

 to the northeast of site C and released in 77 m of water. 

 When we returned to these locations 9 days later, two (7 

 and 9) of the three tags from fish displaced to site C were 

 detected and remained there over the next 36 h. Distinctive 

 double pings from these two tags were heard on the receiver, 

 indicating that the tags had been regurgitated and were on 

 the bottom. 



Fish 10 and 11, which were released at capture site B, were 

 detected ~0.1nmi south of site B 9 days after capture. 

 Signals from the third fish (12) were not detected. The 

 transmitter from displaced Fish 8 was detected ~0.4nmi to 

 the east of the capture site. Within the next 36 h, this fish 

 moved to within 0.2 nmi of the capture location, and its last 

 position was 0.3 nmi from the capture site. 



The submersible Delta was used to dive on one of the tags 

 that was stationary at the displacment location (site C). This 

 transmitter was found lying on top of a large rock. 



1 990 (Figs. 5 and 6) During 1990, transmitters with ARM's 

 were inserted into 12 yellowtail rockfish. All fish were 

 caught during early evening (1900 h) on 15 August in mid- 



^; .. ' 



124 55' 



12'i 



Figure 4 



Locations and tracks of yellowtail rockfish Sebastett 

 Jlat'idus released in 1989. See text for details. Dashed 

 line is the assumed path of Fish 8. 



.;4° 03' - 



;4° 02' ~ 



4 4° 01' 



124° 510' 



Figure 5 



Tracks of 11 yellowtail rockfish Sehast.es Jlamdus cap- 

 tured at site A and released at sites A (dashed lines), 

 B (dotted lines), and C (solid lines) on 15 August 1990. 

 Symbols designate dates and times that positions were 

 obtained (see legend). 



