Shark Records from Longline. Fishing Programs in Hawai'i with Comments on Pacific Ocean Distributions

This paper summarizes records from longline fishing programs conducted in Hawai'i between 1959 and 1980. Data from 11 species of sharks (173 individual sharks) are reported and compared with worldwide records. Although much of the data is nearly 30 yr old, the information was never fully utilized and represents the following important findings. The relationship between clasper length and total length (TL) for bluntnose sixgill shark, Hexanchus griseus (Bonnaterre), indicates that males mature at about 309 cm TL. High fecundity (114 pups) is reported for the prickly shark, Echinorhinus cookei Pietschmann. The smallest mature male E. cookei (183 cm TL) and the smallest pregnant (205 cm TL) bignose shark, Carcharhinus altimus (Springer), are recorded. New maximum depth of capture records for the blacktip shark, Carcharhinus Umbatus (Valenciennes), at 64 m, and for the smooth hammerhead shark, Sphyrna zygaena (L.), at 68 m, are also documented. Distributions of deep-sea sharks in Hawai'i appear to be associated with isothermic submergence, and the sharks remain below the thermocline (100-400 m) and in water temperatures of 9-12°C. Carcharhiniform sharks in Hawai'i range to greater depths than reported elsewhere; this appears to be correlated with the Tropics having warmer water temperatures (20-26°C), which extend down to 100-400 m in depth. Hawai'i were conducted between 1959 and 1976 (for additional details see Wetherbee et al. [1994]). In addition to the control programs, sharks were caught by longline during the Resource Investigations in the Northwestern Hawaiian Islands (RINWHI) conducted from 1978 to 1980 (De Crosta et al. 1984). These longline fishing programs captured IS species of sharks. Despite this extensive fishing effort, accounts have been published for only four of the IS species of sharks, including the sandbar, Carcharhinus plumbeus (Nardo) (Wass 1973); gray reef, C. amblyrhynchos (Bleeker) (Wass 1971, De Crosta et al. 1984, Radtke and Cailliet 1984); Galapagos, C. galapagensis (Snodgrass & Heller) (De Crosta et al. 1984, Wetherbee et al. 1996); and the tiger, Galeocerdo cuvier (Peron & LeSueur) (De Crosta et al. 1984, Lowe et al. 1996). The purpose of this paper is to summarize records of II species of sharks captured by longline fishing in Hawai'i, with an emphasis