It was hypothesized that movement was related to 

 size-at-tagging. To test this, recoveries were grouped 

 into three divisions: <40 cm, 40-60 cm, and >60 cm. 

 These divisions were derived from data presented by 

 Low et al. (footnote 1), and correspond to juvenile, 

 juvenile-maturing, and mature fish, respectively. No 

 significant differences were found among the three 

 groups (Table 5). 



One difficulty in evaluating the recovery informa- 

 tion is the lack of area specific catch and effort data 

 with which to weight recoveries. For example, in 1 973 

 the sablefish fisheries off Oregon and Washington 

 were at a low level, while those off California were ac- 

 tive. Releases made off Oregon in 1972 were recov- 

 ered off California in 1973. In 1974, fisheries off 

 Oregon became active and most of the fish tagged off 

 Oregon were recovered at or near release locations, 

 and many sablefish tagged off California were re- 

 covered off Oregon as well. 



Catch data are available by INPFC area for all na- 

 tions harvesting sablefish. These data can be utilized 

 to provide a rough weighting to tag returns if it is 

 assumed that catch is proportional to effort. Table 6 

 contains the percent of total catch, recoveries, and 

 tagged sablefish for each INPFC area. It can be seen 

 that recoveries for each area were generally propor- 

 tional to releases except for the Monterey, Eureka, 



TABLE 5. — Analysis of variance of distance traveled 

 (km) by sablefish in relation to size at tagging. 



and Vancouver areas in which higher or lower re- 

 coveries occurred due to movement between adja- 

 cent areas. Neither the releases nor recoveries of 

 tagged sablefish was proportional to area sablefish 

 catches. A high percentage of the catch came from 

 the Yakutat and Kodiak areas (30%) while only 0.5 7 

 of the tagged fish and 1.3% of the recoveries occurred 

 in these areas. Conversely, the Columbia and Van- 

 couver areas accounted for 13% of the catch, but 49% 

 of releases and 48% of the recoveries. The Chirikof 

 and Shumagin regions accounted for 15% of the catch 

 (nearly equal to Columbia- Vancouver), but no fish 

 were released in these areas, and only 0.2% of the 

 recoveries occurred in these areas. While general 

 catch data is not a substitute for more detailed catch 

 and effort data, it does indicate that on a gross level 

 estimates of movement did not appear to be influ- 

 enced by the level of fishing as measured by catch. 



Discussion 



The results of this study indicate that for the study 

 period, sablefish are primarily nonmigratory and that 

 most movement is limited to relatively short dis- 

 tances. Long-distance movement was found to occur in 

 only a small portion of the population. These results 

 suggest that the amount of interchange decreases 

 with distance and movement has little effect on abun- 

 dance over long distances. Beamish et al. (1980) 

 reported similar results for sablefish tagging studies 

 performed in the waters of British Columbia. 



The results also provide indications that the north- 

 eastern Pacific sablefish population can be sub- 

 divided into "stocks" or management units. It does 

 appear that sablefish off southern California are in- 

 dependent of those off Oregon and Washington and 

 these are independent of stocks in the eastern Gulf of 

 Alaska, since very little movement occurs over long 

 distances. Finer divisions are suggested by the data, 



Table 6.— Total sablefish catch for 1971-79, the number of sablefish released and 

 recovered (1971-80), and the percentage of total catch, releases, and recoveries with 

 each INPFC area. 



419 



