LOVE ET AL.: LIFE HISTORY AND FISHERY OF CALIFORNIA SCORPIONFISH 



0-30 



31-60 



61-90 

 DEPTH(M) 



91-120 



121-150 151-180 



Figure 2.— Abundances (based on catch per unit effort in the 

 partyboat sport fishery) of California scorpionfish tal<en in six 

 depth intervals in the Southern Calfiornia Bight. 



depth intervals for two seasons— spawning (May- 

 September) and nonspawning (October- April). Dur- 

 ing spawning season, fish were most abundant in 

 61-90 and 121-150 m. Later in the year, there was 

 some inshore movement, and fish were most abun- 

 dant in 0-30 and 31-60 m. However, it was evident 

 that not all scorpionfish migrate to deeper water at 

 the same time during spawning season. Though 

 catches during May-September were highest in 

 deeper water, there were always some mature in- 

 dividuals inshore. Based on our capturing ripe fishes 

 inshore, it is likely that some spawning occurs there. 

 Between 29 April 1983 and 24 September 1984, 

 we tagged 518 California scorpionfish and 23 (4.2%) 

 were recovered. The longest time a fish was at liber- 

 ty was 916 d. Though we tagged fish from a vari- 

 ety of sites, most tagging occurred over Dago Bank. 



The results of our tagging program indicated that 

 many scorpionfish annually return to the same 

 spawning grounds. Of the 17 tag recoveries made 

 on the Dago Bank, all were fish tagged on the same 

 grounds the previous year. The Dago Bank aggre- 

 gation site is occupied by scorpionfish during late 

 spring and summer. Catches as high as 800 scorpion- 

 fish/20-min tow of a 7.6 m otter trawl occur during 

 spawning season. As few scorpionfish live on Dago 

 Bank during the off season, we believe these tag 

 recoveries indicate that the fish return annually to 

 the same area to spawn. The rest of the returns from 

 fish tagged at their spawning grounds were taken 

 inshore during fall and winter, from sites ranging 

 from El Segundo on the north to Long Beach to the 

 south (Fig. 3). The El Segundo individual had 

 travelled at least 42 km from the spawning grounds. 



Based on the SCCWRP and Orange County Sani- 

 tation trawl data, California scorpionfish exhibited 

 considerable variation in abundance between 1974 

 and 1984 (Fig. 4). In the mid-1970's, populations at 

 both sites were relatively low, then increased to a 

 1982 peak and declined rapidly in 1983 and 1984. 

 An analysis of scorpionfish size frequencies indicates 

 this influx was due to an increase in number of 

 mature fishes. The 1983-84 decline was associated 

 with the El Nino event. 



Certainly a number of fish species moved out of 

 their usual haunts during this period (Love et al. 

 1986). However, if this is correct, it is not clear 



,HUNTINGTON 

 vBEACH 



Figure 3.— Location of California scorpionfish tagging and return sites. 



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