Light show is seen at the opening ceremony of the ocean-themed Expo in the southern coastal city of Yeosu, South Korea, on May 11, 2012. The Expo kicked off on Friday, with an opening ceremony that featured a lavish laser light show. (Xinhua/Ji Xinlong)

South Korea kicked off its ocean-themed Expo in the southern coastal city of Yeosu on Friday, with an opening ceremony that featured a lavish laser light show.

A total of 104 countries and 10 international organizations will stage exhibitions throughout the 93 days of the Expo under the theme of "The Living Ocean and Coast."

South Korean media reported that the expo's organizers have spent about 1.8 billion U.S. dollars on constructing a high-tech 250,000-square-meter venue over the last four and a half years.

The ceremony started with the sound of a giant pipe organ echoing through the seafront site, followed by an orchestra concert and traditional music and dance performances.

South Korean President Lee Myung-bak attended the opening ceremony to celebrate the beginning of the global event, marking the second world expo hosted by South Korea after one in 1993 in the city of Daejeon.

"The Yeosu Expo is now open!" Lee declared during the event. Immediately after his declaration, a dazzling display of fireworks lit up the Yeosu sky.

The highlight of the ceremony came with an enormous round- shaped structure in the water called the Big-O, a water screen that is a landmark of the Yeosu Expo, firing off lasers, lights and hologram images.

South Korea's popular K-Pop groups, such as 2NE1 and Big Bang, also joined the opening ceremony, entertaining some 2,400 invited guests.

The Expo, which will run through Aug. 12, will focus on oceans and their potential to tackle climate and environmental challenges that have become a threat to the survival of mankind.

Organizers expect that the event would draw some 10 million local and foreign visitors. They also predict that the expo will help create 80,000 jobs and generate 12.2 trillion won (about 10.6 billion U.S. dollars) in production inducement effect, according to local media.

The Expo opens to the public on Saturday.