The Japanese organizer of the World Cup sailing competition has been criticized for having included a dolphin show in the opening ceremony.

World Sailing, a governing body that seeks to protect marine cetaceans, said in a statement it was "disappointed" that the organizing committee of the World Cup Series in Enoshima, Kanagawa Prefecture, had the sea mammals jump during the ceremony held at an aquarium on Saturday.

Some foreign competitors who took part in the ceremony raised questions about the dolphin show on social media sites. The competition through next Sunday offers sailors the first opportunity to test the venue for the 2020 Tokyo Olympics.

All content in the opening and closing ceremonies of World Sailing events must be approved in advance, the body said, adding no such approval was sought by the organizing committee.

World Sailing "does not condone displays of this nature and apologizes for the misjudgment and any offense caused," the statement said.

Based on its agenda to protect marine cetaceans, the body also said it will provide guidance to committee officials if necessary to ensure the situation does not happen again.

Hirobumi Kawano, who heads the Japan Sailing Federation, said, "We lacked thought" despite efforts accelerating worldwide to protect dolphins and whales.

But he added: "How to treat dolphins differs among countries and individuals. We'd like to apologize if we made someone feel uncomfortable."