The Ecology of the Scalloped Hammerhead Shark, Sphyrna lewini, in Hawaiil

Abstract

Kaneohe Bay, Oahu, is a pupping ground for the scalloped hammerhead shark, Sphyrna lewini, the pups being most abundant between April and October. While in the bay, the pups stay in the most turbid areas by day and move out at night to reef areas where they feed on reef fishes and crustaceans. The pups spend a maximum of three to four months in the bay and then apparently leave nearshore areas. The total number of pups passing through Kaneohe Bay may be as high as 10,000 per year. Adult hammerheads are present inshore also between April and October. They apparently move in for delivery and breeding. Squid beaks in their stomachs indicate that the adults are pelagic the rest of the year-possibly living below the surface layers.