the depths of capture for tagging to 30 m or less. 

 Rockfish caught from depths >30 m usually showed 

 signs of decompression stress, such as loss of equili- 

 brium and eversion of the stomach from swim blad- 

 der expansion. 

 Rockfish suffering from decompression stress can 

 be successfully treated by releasing gases from the 

 swim bladder or behind the eye with a hypodermic 

 needle (Gotshall 1964). Before doing any tagging, we 

 deflated swim bladders of 1 quillback rockfish using 

 Gotshall's technique and held them in an aquarium. 

 All died within 3 mo. Although we are uncertain if all 

 deaths were from decompression stress, we decided 

 to tag fish only from relatively shallow depths, avoid- 

 ing deflation of the swim bladder. 



For tag recoveries, we relied upon voluntary returns 

 from anglers, scuba divers, and commercial fisher- 

 men. To encourage the returns a $2.00 reward was 

 paid for each return, posters advertising the program 

 and the rewards were placed at appropriate 

 locations, and informational reply letters were sent to 

 those who returned the tags. If incomplete recapture 

 information accompanied a returned tag, we would 

 attempt to contact the individual who had caught the 

 fish in order to complete the record. 



During the tagging period we sacrificed a total of 

 389 rockfish specimens to determine sex and state of 

 maturity from external gonadal inspection and age 

 from surface reading of otoliths. It was our intent that 

 the sacrificed fish be representative of the tagged 

 lots. We fullfilled this intent by systematically 

 allocating our field effort between tagging and collec- 

 tion of samples for sacrifice. At each tagging site we 

 would alternate between days for tagging and days 

 for sacrificing. On one day, all fish caught would be 

 tagged; the next day at this site all would be 

 sacrificed — this procedure was followed for the dura- 

 tion of the study. 



Results and Discussion 



Tag Retention 



The lot held to observe tag retention consisted of 6 

 copper, 3 quillback, and 1 black rockfish. After 4 mo, 

 no fish had died or lost tags, and the tag insertion 

 points on the body looked well healed. During the 

 following 20 mo, 1 copper and 3 quillback rockfish 

 died, but this was not, in any way apparent, due to 

 tagging. None of the dead fish showed any necrosis 

 around the tag insertion point, and the tags on all 

 dead fish were well imbedded, intact, and readable. 

 When the retention experiment was terminated after 

 24 mo, the 6 rockfish that were still alive showed no ill 



effects from the tags, and the tags were well imbed- 

 ded, intact, and readable. 



Composition of Sacrificed Lots 



Copper and quillback rockfish tended to be mature 

 and relatively old individuals (Table 1). Sex ratios of 

 these two species were not significantly different 

 from 50:50. On the average, black rockfish were 

 younger than the previous two species, but all the 

 sacrificed fish were mature. There was a significant 

 predominance of male black rockfish over females (x 2 

 = 5.4, 1 df, P< 0.05). Yellowtail rockfish tended to be 

 younger than any of the previous species (x = 5.3 yr) 

 and all were immature. The sexes of the yellowtail 

 rockfish were indistinguishable based on external 

 inspection of gonads. 



TABLE 1. — Age, length, sex, and maturity composition of samples of 

 four species of rockfish collected by hook-and-line concurrently with 

 tagging efforts in the San Juan Islands. Wash., during the period July 

 1975-June 1977. Also shown are means and standard deviations of 

 lengths of samples of these species from the recreational scuba diver 

 and boat angler catch in the San Juan Islands, 1979-80. 



For copper and quillback rockfish ages, the means and upper limits may be too low. 

 Surface readings of otoliths were used for aging which may underestimate ages of 

 rockfish older than about 22 yr according to Beamish (1 979). 



2 Source: La Riviere, M. G, and G. G Bargmann 1 982 The fisheries for bottomfish 

 by scuba divers and recreational anglers in the San Juan Islands during 1 979 and 

 1980. Prog. Rep. Wash., Dep. Fish.. Mar. Fish. Sect (Draft). 



Composition of Tagged Lots 



The mean lengths of the tagged lots of copper, 

 quillback, and yellowtail rockfish (Table 2) con- 

 formed closely to those of the respective sacrificed 

 lots. It is therefore reasonable to assume that vir- 

 tually all the tagged copper and quillback rockfish 

 were mature and that all the tagged yellowtail rock- 

 fish were immature. The tagged black rockfish lot 

 averaged less in length than the sacrificed lot for no 

 apparent reason other than random sampling effects 

 (36.0 cm vs. 41.0 cm), and may therefore have 

 included some immature individuals. McClure 

 (1982) indicated that 5-yr-old male and 6-yr-old 



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