A comedic fantasy movie denouncing the human toll on marine wildlife has broken China's national box office record -- a sign of increasing environmental awareness among the Chinese public, NGOs said Wednesday.

"The Mermaid", brainchild of Hong Kong actor-director Stephen Chow, known abroad for his jokey, kung-fu-laden hit "Shaolin Soccer", had taken 2.89 billion yuan ($456 million) at the Chinese box office by Wednesday, just over two weeks after its debut, according to the website China Box Office.

Its total stands far above the 825 million yuan raked in by "Star Wars: The Force Awakens" ($127 million) in China, or the 542 million from the James Bond movie "Spectre".

The environmental romantic comedy, filmed in 3D, recounts the adventures of male and female mermaids planning to assassinate a ruthless real estate magnate who has bought a nature reserve and is killing its native dolphins.

"It's good news that movies about the environment can arouse such public interest," May Mei, China director of the NGO WildAid, told AFP.

The film, helped along by a star-studded cast, carries a political weight despite its many gags -- a rarity for Chinese cinema, which tends to be geared towards pure mass entertainment.

"What I most wanted to depict wasn't a love story, but man's destruction of the environment," its director told Phoenix TV.

"In the past 10 years, we've seen a growing public awareness on these sorts of issues," Mei said, citing examples of controversy over shark fin, used as an ingredient in expensive dishes favoured by wealthy Chinese.

"In 2006, very few people knew the impact their consumption was having on the reduction of shark populations," Mei explained.

By 2013, 96 percent of Chinese were aware of the environmental toll of the once-prized delicacy, according to a WildAid survey.

Former NBA star Yao Ming has taken part in high-profile advertising campaigns against shark fin consumption and ivory use, while the actor Jackie Chan appeared in a World Wildlife Foundation video clip to promote the protection of wild animals.

Zhang Yuanyuan, China head of the animal protection group ActAsia, described their efforts as "an important reflection of society's progress", and pointed out the "growing public demand" for environmentally-themed stories.

In 2015, a documentary about China's toxic pollution called "Under the Dome" went viral -- before disappearing from video sites -- highlighting growing awareness of the issue and inspiring many in the country to consult indices measuring air pollution on their smartphones.