Eight beluga whales jump in unison out of a bright blue indoor pool, flipping their tail fins and spewing water as a packed audience cheers and snaps photographs.

Whale shows like the one at Chimelong Ocean Kingdom, located in Zhuhai on China's southern coast, are proliferating at new marine parks across the country, driving demand for threatened species.

Orcas and beluga whales are among the marine animals caught up in a shadowy trade in which individual cetaceans — often caught illegally — sell for millions of dollars, according to scientists, executives and activists.