A Review of Shark Control in Hawaii with Recommendations for Future Research

In an attempt to allay public fears and to reduce the risk of shark attack, the state government of Hawaii spent over $300,000 on shark control programs between 1959 and 1976. Six control programs of various intensity resulted in the killing of 4,668 sharks at an average cost of $182 per shark. The programs furnished information on diet, reproduction, and distribution of sharks in Hawaii, but research efforts of the programs had a number of shortcomings. Analysis of the biological data gathered was not directed toward the tiger shark, Galeocerdo cuvier (Peron & LeSueur), which is responsible for most attacks in Hawaii. Reliable estimates of shark populations in Hawaii cannot be made based on catch data from control programs because of sampling biases. Most of the information gained from the control programs was not published in reviewed journals and is not readily available to the scientific community. The ability of the control programs to reduce shark populations and to remove large sharks from coastal waters appears to have been stated with more confidence than is warranted, considering seasonal changes observed in shark abundance and variable fishing effort. Shark control programs do not appear to have had measurable effects on the rate of shark attacks in Hawaiian waters. Implementation of large-scale control programs in the future in Hawaii may not be appropriate. Increased understanding of the behavior and biology of target species is necessary for evaluation of the effectiveness of small-scale control efforts, such as selective fishing after an attack. Acoustic telemetry, conventional tagging, and studies on population dynamics concentrating primarily on the tiger shark may be used to obtain data about activity patterns, distribution, and population parameters, providing information useful for reducing the risk of shark attack in Hawaii and elsewhere. As THE HUMAN POPULAnON in Hawaii has risen, ocean resources have become increasingly exploited. In addition, Hawaii's increasing resident and tourist populations have placed a high priority on coastal recreation. Expanded recreational use of the ocean brings the potential for increasing shark-human interactions. Fear of shark attack, coupled with socioeconomic pressures of tourism, prompted the state of Hawaii to establish a shark control program in 1959 (Ikehara 1961), 1 Manuscript accepted 27 July 1993. 2 Department of Zoology, University of Hawaii at Manoa, Honolulu, Hawaii 96822. 3 Waikiki Aquarium, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 2777 Kalakaua Avenue, Honolulu, Hawaii 96815. 95 which was followed by other programs in 1966-1969 (Tester 1968, 1969, Norris and Harvey 1969), 1971 (Fujimoto and Sakuda 1971), and 1976 (Naftel 1976, Naftel et al. 1976). Two recent fatal shark attacks in Hawaii have prompted calls for reinstitution of a large-scale shark control program. Because of the limited availability of data from past control programs and continued debate over the appropriateness of shark control in Hawaii, this paper provides a summary and critical review of past shark control programs in Hawaii with regard to: (1) objectives of the programs; (2) results and new information gained; (3) evaluation of success. This paper also assesses the potential for future shark control programs and provides suggestions for further research to increase under96 PACIFIC SCIENCE, Volume 48, April 1994 standing of shark behavior and to provide off Lanikai, Oahu (Tester 1960). To minimize information that may be useful for reducing the hazard to surfers and swimmers posed by shark-human interactions. sharks, Hawaii's first shark control program (the Billy Weaver Shark Research and Control Program) was established. The intent of PAST SHARK CONTROL PROGRAMS IN HAWAII the program was to reduce shark populations in coastal waters around Oahu and to compile The Billy Weaver Shark Research and data for future use in controlling shark abunControl Program, 1959-1960 dance. The Hawaii Board of Agriculture and Forestry was assigned to direct and supervise On 13 December 1958 a teenage surfer, fishing operations and collection of biological Billy Weaver, was fatally attacked by a shark and ecological data (Ikehara 1961).