Illegal poaching, fishing and logging are occurring in almost half of all Unesco World Heritage sites, according to a new report published by the World Wildlife Fund.
Entitled "Not For Sale", the enquiry states that endangered species are being targeted in 45% of these protected areas, of which there are some 200 around the globe.
Considered some of the world's most precious natural sites, these areas are home to thousands of rare plants and animals, including almost a third of the world's remaining tigers and 40% of all African Elephants.
They are also the last remaining areas to welcome several severely threatened species such as the Java rhino in Indonesia and the vaquita in the Gulf of California.
As the NGO's head of campaigns Chris Gee notes:
"Not only does this threaten the survival of species, but it’s also jeopardising the future heritage of these precious places and the people whose livelihoods depend on them."
According to the report, the "vulnerable" species, such as elephants, rhinos and tigers, is happening in at least 43 natural heritage sites, while illegal logging of rare plants, such as rosewood and ebony, is happening is around 26 sites.
Illegal fishing is thought to be happening in around 18 out of 39 protected marine areas. As head of WWF International Marco Lambertini notes:
"Natural world heritage sites are among the most recognised natural sites for their universal value.
Yet many are threatened by destructive industrial activities and their often unique animals and plants are also affected by overexploitation and trafficking. Unless they are protected effectively, we will lose them forever."
The WWF estimates that elephant poaching costs African economies around $25 million per year from losses in tourist revenue.
The NGO is calling for better collaboration between the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Unesco World Heritage centre in order to put an end to illegal activity in these areas.