When experts from around the world decided to gather on Hawaii to decide which animals and plants were endangered, they could have hardly chosen a better venue.

For the beautiful and unique flora of the Pacific islands has been devastated by the arrival of invasive species and animals brought deliberately or accidentally by humans.

Of the 415 endemic species assessed for the International Union for Conservation of Nature’s ‘Red List’, 87 per cent are threatened with extinction, including a beautiful flowering tree found only on the island of Kaua’i, called the 'ohe kiko ‘ola.

Thirty-eight species have been listed as extinct, including the shrubs 'oha wai, with four species declared extinct in the wild such as the haha plant Cyanea superba, which was last seen in the wild in 2003.

Matt Keir, a member of the IUCN’s Hawaiian Plant Specialist Group, wrote in a statement: “Hawaiʻi is an example of nature at its best with spectacular examples of evolution, yet it is facing an uncertain future due to the impact of invasive species — showing how unwittingly, human actions can make nature turn against itself.

“What we see happening in Hawaiʻi is foretelling what will happen in other island or contained ecological systems.

The haha plant, Cyanea superba, has been declared extinct in the wild (US Army Environmental Command via Wikipedia)

“Hawaiʻi and other nations must take urgent action to stop the spread of invasive species and to protect species with small population sizes.”

There are some 250 species found on the islands with less than 50 mature individuals left.

In an email to The Independent, Mr Keir wrote that while extinction could be part of natural life, this was normally a “slow gradual process”.

“The causes of extinction of Hawaiian plants is due to the introduction of new organisms which have been rapidly introduced to our islands,” he said.

“Hawaii is one of the most isolated places on earth and the few plants that got here over millions of years and radiated into many new species. In the last 200 years, we have brought in diseases that have killed the birds and insects which pollinated flowers and dispersed seeds.

“Inadvertent introductions of rats, birds, and mice have happened and now they eat plants and seeds. Large mammals brought in for food trample and browse through a forest that had never had that kind or animal before.”

However he added that hundreds of native species were being restored by dozens of different conservation groups.

“Koa forests are bring replanted, rainforests are being protected and there are many success stories about recovery,” he said.

Animals in decline Show all 8 1 /8 Animals in decline Animals in decline Harbour seal (Phoca vitulina) Where: Orkney Islands. What: Between 2001-2006, numbers in Orkney declined by 40 per cent. Why: epidemics of the phocine distemper virus are thought to have caused major declines, but the killing of seals in the Moray Firth to protect salmon farms may have an impact. Alamy Animals in decline African lion (Panthera leo) Where: Ghana. What: In Ghana’s Mole National Park, lion numbers have declined by more than 90 per cent in 40 years. Why: local conflicts are thought to have contributed to the slaughter of lions and are a worrying example of the status of the animal in Western and Central Africa. Animals in decline Leatherback turtle (Dermochelys coriacea) Where: Indonesia, Malaysia, Mexico, Costa Rica. What: Numbers are down in both the Atlantic and Pacific. It declined by 95 per cent between 1989-2002 in Costa Rica. Why: mainly due to them being caught as bycatch, but they’ve also been affected by local developments. Alamy Animals in decline Wandering albatross (Diomedea exulans) Where: South Atlantic. What: A rapid decline. One population, from Bird Island, South Georgia, declined by 50 per cent between 1972-2010, according to the British Antarctic Survey. Why: being caught in various commercial longline fisheries. Alamy Animals in decline Saiga Antelope (Saiga tatarica) Where: Kazakhstan, Mongolia, Russia, Turkmenistan, Uzbekistan. What: fall in populations has been dramatic. In the early 1990s numbers were over a million, but are now estimated to be around 50,000. Why: the break up of the former USSR led to uncontrolled hunting. Increased rural poverty means the species is hunted for its meat Animals in decline Swordfish (Xiphias gladius) Where: found worldwide in tropical, subtropical and temperate seas. Why: at risk from overfishing and as a target in recreational fishing. A significant number of swordfish are also caught by illegal driftnet fisheries in the Mediterranean Animals in decline Argali Sheep (Ovis mammon) Where: Central and Southern Asian mountains,usually at 3,000-5,000 metres altitude. Why: domesticated herds of sheep competing for grazing grounds. Over-hunting and poaching. Animals in decline Humphead Wrasse (Cheilinus undulatus) Where: the Indo-Pacific, from the Red Sea to South Africa and to the Tuamoto Islands (Polynesia), north to the Ryukyu Islands (south-west Japan), and south to New Caledonia. Why: Illegal, Unregulated and Unreported (IUU) fishing and trading of the species

Asked what will happen if nothing is done to control the spread of invasive species from one place to another, Mr Keir painted a bleak picture.

“We will lose biodiversity and more of the world will look the same. We will diminish the wonderful variety of life and all of the values each of the species brings,” he said.

“We will see ecosystems collapse as they have new organisms forced on them too quickly, undermining the stability they have developed over millions of years.