The History of Horseshoe Crab Research and Conservation in Japan

Abstract

Scientific studies of the Japanese horseshoe crab, Tachypleus tridentatus, from the Seto Inland Sea have been published for nearly a century, beginning with the pioneering work of Owhatari (1913). Studies by Matsunari, Asano, Oka, Nishii, Sekiguchi, and many others established much of the basic reproductive biology of the species in the vicinity of Kasaoka City. Oe-hama beach was designated as a “Horseshoe Crab Spawning Ground Natural Monument” in 1928. In spite of this formal recognition, and in the face of opposition by various local conservation organizations, the Kasaoka Bay Land Reclamation Project began in 1969. Horseshoe crab abundance since then has declined, which has stimulated efforts to raise horseshoe crabs in captivity. The success of such projects, though small in scale, affords some hope that horseshoe crab populations might experience recovery.