Two shark species, namely the whale shark and the winghead shark, now inch closer to extinction, after the International Union for the Conservation of Nature (IUCN) reclassified the two species as "endangered" from a "vulnerable" status on the group's Red List.

Aside from the two shark species, Bornean orangutans have also been reassessed from "endangered" to "critically endangered," one step from going completely extinct.

The new assessment revealed that the "growing human pressures" on these species have put them under great risk of being completely killed off, the group said in a news release.

"These new IUCN Red List assessments emphasize how urgent it is for the conservation community to act strategically to protect or planet's incredible diversity of life," said Jane Smart, director of the IUCN's Global Species Programmme.

Whale sharks (Rhincodon typu) are the world's largest fish. Their population dwindled by half over the last 75 years.

Despite conservation efforts in various countries, such as the Philippines and India, and regulation of the whale shark trade, they are continuously being fished out of waters, usually as by-catch of tuna fishers.

These slow-moving marine giants also get killed by ship propellers.

Unregulated fishing is also to be blamed for the population decline of the winghead shark (Eusphyra blochii), a species of hammerhead shark. They also get entangled in fishing nets due to their distinctive shape.

Bornean orangutans (Pongo pygmaeus), meanwhile, face the threat of habitat loss, as forests are turned into rubber, oil palm or paper plantations. They also face the risk of being killed off by humans.

The World Wildlife Fund for Nature also reported illegal pet trade as a threat to the orangutans' number.

The IUCN reported that the number of Bornean orangutans dropped to 100,000 from 288,500 in 1970s, as per The Independent. This number is expected to further shrink to 47,000 in the next nine years.

The IUCN Red List is recognized as the most comprehensive and objective evaluation and listing of global conservation status of biological species. The new full list will be revealed in September.