Conservationists around the globe reacted swiftly to news about the tournament.
Rafael Garcia, director of Spanish-based Planeta Buceo, an online scuba diving and travel site, launched a petition that has gathered more than 1,200 signatures. He and others requested that Dominican President Danilo Medina stop the tournament.
"It causes us great sadness that people hunt sharks for fun and see them as an obstacle to tourism," Garcia said in a telephone interview from Spain.
He said he learned about the tournament by reading comments from outraged divers on several international forums.
Shark hunting tournaments are relatively rare, although an estimated 26 million to 73 million sharks are caught annually, especially to meet demand in countries like China where shark fins are used to make soups and traditional cures.