A current study suggests that the damage to biodiversity in the tropics could even be worse than expected if we don't get a grip on the environmental problems there.

An international team of researchers from around the world put a figure on biodiversity in tropical regions, looking at forests, savannahs, freshwater regions and coastlines.

Their results: Even though the tropics cover only about 40 percent of the Earth's surface, they harbor a whopping 78 percent of all plant and animal species, including amphibians, terrestrial mammals, fish, ants and flowering plants.

And these tropical regions are even more important for birds: 91 percent of all terrestrial birds live in those warm and humid zones. Many more living elsewhere cross or visit the tropics on their annual migrations.

The tropics are also home of almost all shallow-water corals known so far.

Most of these tropical species are found nowhere else, and researchers estimate that at least 150,000 species are as yet unknown to science.

Read more: Scientists race to name unknown species before biodiversity disappears

"At the current rate of species description — about 20,000 new species per year — it can be estimated that at least 300 years will be necessary to catalogue biodiversity," Benoit Guénard, assistant professor of the University of Hong Kong, says in a press release accompanying the study.

Top 10 newly discovered species for 2018 Isolated population of rare great apes found in Indonesia Orangutans are the only great apes in Asia. In 2001, the orangutans of Sumatra and Borneo were recognized as two distinct species. Now, researchers have found a third: the Tapanuli orangutan, which lives in the southern range of Sumatran orangutans, in Batang Toru. They are, in fact, the most imperiled great apes in the world. Only an estimated 800 individuals exist in a fragmented habitat.

Top 10 newly discovered species for 2018 Majestic tree found in the Atlantic forest in Brazil Towering up to 40 meters (130 feet) high and weighing an estimated 56,000 kilos (62 tons), this majestic tree, named Dinizia jueirana-facao, was found in the Atlantic forest in northern Espirito Santo, Brazil. Large in dimensions, the tree is limited in numbers – only 25 of the trees exist, making it a critically endangered species.

Top 10 newly discovered species for 2018 Beetle that looks like part of an ant found in Costa Rica This tiny beetle is called Nymphister kronaueri and lives among ants in Costa Rica. The beetle is only 1.5 millimeters long (0.05 inches) and its body is the precise size, shape and color of the abdomen of a worker ant. When the nomadic ants move to a new location, the beetle travels along, using its mouthparts to grab onto the abdomen of its host, letting the ant do all the walking.

Top 10 newly discovered species for 2018 Deepest fish in the sea found in the Western Pacific Ocean The dark abyss of the Mariana Trench in the western Pacific contains the deepest spot in the world's oceans. And that's where the pseudoliparis swirei was found, a small, tadpole-like fish that belongs to the snailfish family and measures 12 centimeters (4 inches) in length. It's the deepest-dwelling fish ever recorded, captured at depths of between 6,800 and 7,900 meters (22,000 and 26,000 feet).

Top 10 newly discovered species for 2018 Plant that partners with a fungus found in Japan Most plants capture solar energy to feed themselves via photosynthesis. A few, like the newly discovered S. sugimotoi, get their sustenance from other organisms. In this case, the plant is symbiotic with a fungus, which it derives nutrition from without harming it. Its delicate pink blossoms only appear during a short flowering peroid, on Japan's Ishigaki Island.

Top 10 newly discovered species for 2018 Bright amphipod found in the chilly waters of the Antarctic Ocean This invertebrate, about 5 centimeters (2 inches) in length, was spotted in the glacial waters of the Southern Ocean encircling Antarctica. It's an amphipod called Epimeria quasimodo, in reference to its somewhat humped back. It has incredible spines and vivid colors and its crested adornments are reminiscent of mythological dragons.

Top 10 newly discovered species for 2018 Bacterium that looks like hair found on the Canary Islands When a submarine volcano erupted off the coast of El Hierro in the Canary Islands, it wiped out much of the existing marine ecosystem. But scientists have found the first colonizers of this deposited area: Thiolava veneris, a new species of proteobacteria producing long, hair-like structures composed of bacterial cells within a sheath and forming a massive white mat.

Top 10 newly discovered species for 2018 Fossil of a marsupial lion found in Australia Scientists recovered fossils in Queensland, Australia to a previously unknown lion-like marsupial that roamed Australia's open forest in the late Oligocene age, which ended about 23 million years ago. It was about the size of a Siberian husky dog and spent part of its time in trees. Its teeth suggest it was not completely reliant on meat but was, rather, an omnivore.

Top 10 newly discovered species for 2018 Unicellular organism found in an aquarium in California This single-celled protist was discovered on a brain coral in an aquarium in San Diego, California, USA. The geographic origin of the species in the wild is not known. It's called ancoracysta twistan and is a predatory flagellate that uses its whip-like flagella to propel itself, and unusual harpoon-like organelles to immobilize other protists on which it feeds.

Top 10 newly discovered species for 2018 Cave-dwelling beetle found in China A new species of troglobitic beetle adapted to life in the permanent darkness of caves was discovered in a cave in Du'an, Guangxi Province, China. Called Xuedytes bellus, the beetle only grows to about 9 millimeters (half an inch) in length and is striking in the dramatic elongation of its head and the body segment immediately behind the head. Author: Anne-Sophie Brändlin



"We have far less knowledge on the species that live in the tropics compared to those in temperate areas," Yves Basset, researcher with Smithsonian Tropical Research Institute, who was not involved in the study, tells DW.

"But we know that the majority of species live in the tropics," he says adding that this is also true for insects — the animals that he focuses on in his research.

There are many hypothesis on why so many more species have evolved in the tropics.

But those "hyperdiverse tropical ecosystems" — as the researchers call them — are disappearing.

Tropics in trouble

Deforestation, pollution, overfishing, overhunting, invasive species and ultimately global warming are all taking their toll on tropical ecosystems.

Read more: Five of the world's biggest environmental problems

"They are undergoing drastic transition, changing from what they were before, to something completely different," lead author Jos Barlow from Lancaster University tells DW.

Coral reefs, for example, get overgrown and finally replaced by fields of algae and sponges.

Wildfires in humid tropical forests, which used to be fire-free in the past, can result in grassy vegetation taking over.

Most wildfires tropical in regions are human-caused

In many savannas such as the Brazilian Cerrado, in turn, trees planted for harvest are taking over the ecosystem.

"These events are happening now, and they are happening with greater frequencies and with larger extents over time," Barlow says.

This loss of ecosystem can have dramatic negative effects for humans as well, the researchers add.

Coral reefs, for example, provide fish resources for the 275 million people that live within 30 kilometers (19 miles) of them while forests provide timber and other products. And the evaporation in Amazonia is estimated to provide 70 percent of the rainfall in the 3.2-million square kilometer area next to it.

Tropical ecosystems are already contending with many local threats, such as pollution and logging. Climate change might be the last straw.

"While most of us are familiar with the impact of climate change on the polar regions, it is also having devastating consequences across the tropics — and without urgent action, could undermine local conservation," Barlow says.

Read more: Climate change threatens half of wildlife in biodiversity hotspots, study says

Multiple stressors, such as pollution and global warming "can interact in myriad ways," the researchers write.

In such cases, a collapse becomes imminent.

Asked what he most urgently wished for to preserve the tropics, Jos Barlow answers: "to control climate change."

Current environmental action not enough

Establishing protected areas is one approach to conserving biodiversity.

The world has seen an "enormous increase" in coverage of protected areas, both terrestrial and marine, Barlow points out. "These are extremely important, and have huge potential to preserve and conserve biodiversity." he says.

Marine protected areas in pictures Pacific Remote Islands Marine National Monument Covering an area of almost 1.3 million square kilometers (800,000 square miles), this is among the world's largest marine protected areas. Located in the western Pacific Ocean, it is home to all manner of marine life including green turtles, pearl oysters, giant clams, reef sharks, coconut crabs, dolphins and whales.

Marine protected areas in pictures Pitcairn Islands Marine Reserve Surrounding this British Overseas Territory lies the largest contiguous marine protected area in the world. The 834,334 square kilometers of pristine ocean habitat are monitored via satellite to track potential illegal fishing activity in this vast and remote corner of the South Pacific.

Marine protected areas in pictures The Great Barrier Reef Marine Park Situated off the northeastern coast of Australia, the Great Barrier Reef is the largest in the world. A vast area of that reef, which is so big it can be seen from space, forms the Great Barrier Reef Marine Park. The reef saw devastating coral bleaching in 2016 and 2017. In an effort to protect the delicate ecosystem, fishing is strictly regulated and commercial ships can only use certain routes.

Marine protected areas in pictures Galapagos Marine Reserve A UNESCO World Heritage Site and home to many animals found nowhere else in the world, the Galapagos Marine Reserve in the Pacific Ocean is administered by Ecuador and is the largest marine park in a developing country.

Marine protected areas in pictures Bowie Seamount marine protected area The Bowie Seamount is an underwater volcano located 180 kilometers off the west coast of Canada. Although the volcano rises about 3,000 meters from the ocean bed, its highest point is 24 meters below sea level. While it may be invisible to those of us living above water, the submerged mountain is home to a rich mix of marine fauna and flora.

Marine protected areas in pictures Chagos archipelago The United Kingdom declared this vast stretch of Indian Ocean a marine protected area in 2010. The legality of the move has been contested by Mauritius, which lays claim to the group of islands. In the 1970s, the UK evicted the entire native population from the archipelago and granted the United States permission to use it as a military base.

Marine protected areas in pictures The Schleswig-Holstein Wadden Sea National Park Extending from the German-Danish maritime border down to the Elbe estuary, and with an area of 4,410 square kilometers, this is doubtless Germany’s largest national park. Due to the intertidal nature of the Wadden Sea, some 30 percent of it is only periodically under water.

Marine protected areas in pictures The Pelagos Sanctuary for Mediterranean Marine Mammals Covering a large area between the French Riviera, Sardinia and the Italian region of Tuscany, this sanctuary was established specifically to protect marine mammals. It is currently the world's only conservation area in international waters.

Marine protected areas in pictures Ross Sea Region Marine Protected Area In October 2016, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) agreed to create a marine protected area off the coast of Antarctica. However, the 1.6 million square kilometers of pristine wilderness will only be protected for 35 years. What happens after remains to be seen.

Marine protected areas in pictures Aquatic Reserve of the South of Gabon The government of Gabon announced in June 2017 creation of a 53,000-square-kilometer network of marine protected areas - the largest in Africa. It would apply to a quarter of Gabon's seas, which are incredibly rich in life, including sea turtles, whales, dolphins, corals, even crocodiles. The region is known for rampant overfishing - the reserves are accompanied by a sustainable fishing plan.

Marine protected areas in pictures Cook Islands Marine Park In July 2017, the Cook Islands - a small island nation about halfway between New Zealand and Hawaii - approved designation of the world's new largest marine sanctuaries off its shores. The 1.9-million-square-kilometer preserve includes a core no-fishing zone, otherwise limits on mineral extraction and commercial fishing. It's hoped to help preserve the archipelago's lagoons and reefs. Author: Harald Franzen



But nature reserves alone are not the solution.

The study finds that the current network of proected areas remains poorly designed and covers too little tropical freshwaters and grasslands.

Moreover, protecting only what's inside the boundaries of a nature reserve, doesn't prevent biodiversity loss outside.

This strategy "fails to engage with the distal drivers of bioversity loss," they write in Nature.

Those drivers include population growth, deeply rooted inequalities between developed and developing countries, and the increasing value of natural resources coming from the tropics, such as timber, soy beans, palm oil or even the scales of a pangolin.

Christina Hicks from Lancaster University said in the press release that industrialized countries play a huge role in causing environmental problems in the tropics. Environmental aid has been "static" in recent years, "and remains a drop in the ocean compared to the income generated by resource extraction."

Amphibians like this tree frog are among the most threatened of all animal species

Multinational efforts required

The researchers call for a joint approach to managing resources and ecosystems.

"We need multinational efforts that span borders, because many of these issues aren't constrained within a particular country," Barlow says.

Understanding and controlling supply chains might be a key measure, making sure that the products we buy in European or US stores don't harm the environment in the tropics.

"Consumer information is really important, but also legal requirements preventing the import of products that show unsustainable supply chains."

The researchers praise France's radical new law loi de vigilance. It imposes due diligence on multinational corporations to prevent serious human rights abuses and environmental risks in their supply chains that extend beyond French borders.

Read more: The difficult task of tracking deadly wood

Barlow says there is still hope to preserve the tropics as the biodiversity treasure trove that it is now.

"If you go to the tropics now, you can still see this wonderful biodiversity. However, we really need to act soon and change the way we are approaching its conservation."