Abstract. Bottom longline 



and baited video camera operations 

 were conducted at 39 stations off 

 the Hawaiian Islands of Oahu, 

 Maui, and Kauai during 1992. Ob- 

 jectives of the 1992 cruise were to 

 assess the precision, accuracy, and 

 efficiency of a video camera system 

 versus a traditional abundance in- 

 dex (longline catch per unit of ef- 

 fort [CPUE]) for juvenile pink 

 snapper ("opakapaka"), Pristi- 

 pomoides filamentosus, a commer- 

 cially important eteline snapper in 

 Hawaii. Precision of the video 

 samples was reevaluated with data 

 from 18 stations sampled during 

 1993 off Kaneohe Bay. The video 

 index of the maximum number of 

 opakapaka observed (MAXNO, the 

 natural log-transformed mean of 

 three camera drops) was best cor- 

 related with the log of longline 

 CPUE (r=0.79, P<0.001, n = 15). 

 Variation in the data for video 

 MAXNO was nominally less than 

 that of the longline CPUE. No 

 monotone trend over stations was 

 noted in samples from 1993. 

 Sample sizes of 33 stations for 

 longline and 18 stations for video 

 would be necessary to detect two- 

 fold changes in abundance of 

 opakapaka at a site, based on our 

 analysis of the two end positions of 

 the 10 windward Oahu stations 

 that had three quantitative deploy- 

 ments. Reanalysis of power with 

 data from the 1993 cruise indicates 

 that a sample size of approximately 

 22 stations (cc 2 =0.05) or approxi- 

 mately 17 stations (a 2 =0.1) would 

 be necessary to detect twofold 

 changes. 



Evaluation of a video camera 

 technique for indexing abundances 

 of juvenile pink snapper, 

 Pristipomoides filamentosus, and 

 other Hawaiian insular shelf fishes 



Denise M. Ellis 

 Edward E. DeMartini 



Honolulu Laboratory, Southwest Fisheries Center 



National Marine Fisheries Service. NO/V\ 



2570 Dole Street, Honolulu, Hawaii 96822-2396 



Manuscript accepted 23 May 1994. 

 Fishery Bulletin 93:67-77 (1995). 



Deep-water snappers (family: Lut- 

 janidae ) support an important com- 

 mercial fishery around the main 

 Hawaiian Islands (MHI) and the 

 Northwestern Hawaiian Islands 

 (NWHI). Pink snapper (or "opaka- 

 paka"), Pristipomoides filamen- 

 tosus, has been one of the most im- 

 portant species in terms of landings 

 (20-30% of total weight) and rev- 

 enue for many years 1 (Ralston and 

 Polovina, 1982; WPRFMC 2 ). Re- 

 search on adult P. filamentosus has 

 included studies on sexual maturity 

 and growth (Ralston and Miyamoto, 

 1983; Kikkawa, 1984; Okamoto 3 ), 

 trophic ecology (Parrish, 1987; 

 Haight et al., 1993); distribution 

 (Kami, 1973; Moffitt, 1980); habitat 

 (Ralston et al., 1986; Moffitt et al., 

 1989); and mortality (Ralston, 

 1987). Relatively few larval and 

 pelagic juvenile specimens of opaka- 

 paka have been collected; therefore, 

 little is known of their early life his- 

 tory (Leis, 1987). 



Exploratory research on re- 

 cruited, epibenthic juvenile P. fila- 

 mentosus has been conducted by the 

 Honolulu Laboratory of the Na- 

 tional Marine Fisheries Service 

 (NMFS) since 1988. This has in- 

 cluded initial habitat description 4 

 and work on age and growth of ju- 

 veniles at Kaneohe Bay, Oahu 

 (Parrish, 1989; DeMartini et al., 



1994). Recent work has focused on 

 evaluating techniques for assessing 

 the distribution and abundance of 

 juvenile opakapaka in Hawaiian 

 waters. Characterizations of juve- 

 nile opakapaka abundance based on 

 rod and reel, handlines, and bottom 

 trawls, however, are either biased, 

 imprecise, or destructive of habitat. 5 



1 Kawamoto, K. E. 1992. Northwestern Ha- 

 waiian Islands bottomfish fishery, 1991. 

 Southwest Fish. Sci. Cent., Natl. Mar. 

 Fish. Serv., NOAA, Honolulu, HI 96822- 

 2396. Southwest Fish. Sci. Cent. Admin. 

 Rep. H-92-12, 20 p. 



2 WPRFMC (Western Pacific Regional Fish- 

 eries Management Council). 1992. 

 Bottomfish and seamount groundfish fish- 

 eries of the Western Pacific region, p. 57- 

 71. 1991 Annual Report for the WPRFMC, 

 Honolulu, HI 96813. 



3 Okamoto, H. Y. 1993. Project to develop 

 opakapaka (pink snapper) tagging tech- 

 niques to assess movement behavior. Sept 

 1, 1990 to Aug. 31, 1992. Final Rep. of HI 

 Dep. Land and Nat. Res. (HDLNR) to 

 NOAA., Award no. NA90AA-D-IJ466 

 HDLNR, DAR, Honolulu, HI 96814, 18 p 



4 Moffitt, R. B., and F. A. Parrish. In review. 

 Habitat use and life history of juvenile 

 Hawaiian pink snappers, Pristipomoides 

 filamentosus. Bull. Mar. Sci. 



5 Ellis, D. M„ E. E. DeMartini, and R. B. 

 Moffitt. 1992. Bottom trawl catches of ju- 

 venile opakapaka, Pristipomoides fila- 

 mentosus (F. Lutjanidae), and associated 

 fishes, Townsend Cromwell cruise TC-90- 

 10, 1990. Honolulu Lab., Southwest Fish. 

 Sci. Cent., Natl. Mar. Fish. Serv., NOAA, 

 Honolulu, HI 96822-2396. Southwest Fish. 

 Sci. Cent. Admin. Rep H-92-03, 33 p. 



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