This was first quantified in 2012, when scientists estimated that trade and exports accounted for a third of all threats to wildlife. But for the first time, a study by researchers in Japan and Norway pinpoints the affected habitats of all those species — in the hope of helping to focus the work of conservationists who track the effect of human trade.
The researchers, Daniel Moran of the Norwegian University of Science and Technology and Keiichiro Kanemoto of Shinshu University in Japan, laid relatively new global supply-chain databases over the habitats of endangered species listed by the International Union for the Conservation of Nature (IUCN) and BirdLife International. That identified areas the scientists call threatened biodiversity hot spots. The research was published this week in the journal Nature Ecology and Evolution.
“Biodiversity hot spots is a well studied topic, and it is known that the last reserves of biodiversity are harbored in a small number of places,” Moran said Wednesday by email. “Economic pressure, even at the margin and in small increments, exerts pressure at these places. Almost any human pressure at the places, unless very well managed, will have a big impact on species there.”
Logging in Brazil to create products that wind up in the United States, for example, cuts down trees used by red-face spider monkeys. Fishery trade and gold mined and bound for Japan affects mangroves off Papua New Guinea that are home to diverse plant species and an endangered sea cow. A hydroelectric dam that traps water to irrigate agriculture, including trees that produce palm oil exported to other parts of Europe and the United States, threatens the Iberian lynx.
Product demand in the United States also affects “marine hot spots off the Caribbean coast of Costa Rica and Nicaragua at the mouth of the Orinoco around Trinidad and Tobago,” the study says. “The European Union drives threats [in] hot spots outside Southeast Asia in the islands around Madagascar: Réunion, Mauritius, Seychelles.
“Despite much attention on the Amazon rain forest, the U.S. footprint in Brazil is actually greater in southern Brazil, the Brazilian Highlands, where agriculture and grazing are extensive, than inside the Amazon basin, although impacts along the Amazon river itself are high,” the study notes.
Because human encroachment on animal habitats has pushed wildlife together, a small degree of impact resonates widely. “For threats driven by U.S. consumption, the 5 percent most intensively affected land area covers 23.6 percent of its total impact on species, and at sea the 5 percent most intensively impacted marine area affects 60.7 percent of threatened species habitats,” according to the study.
“Almost all food and fiber is implicated,” Moran said. Yet not every threat to animals can be attributed to industry. Disease kills multitudes of wildlife, and invasive species, another byproduct of international trade, kill native animals and compete with them for habitat. Individual products used by humans are a limited threat, but there are so many products that they amount to death by a thousand cuts.
“Together they add up,” Moran said. “In general, it is very difficult to find a specific threat cause; species lose ground due to a combination of factors like habitat loss, habitat fragmentation, pollution, climate change.”