Study identified population reduction of 79% of endemic ant species in Fiji. Researchers associate the decline with a global problem that affects less isolated ecosystems.
At least 79% of the endemic species of ants in the Fiji archipelago are experiencing a strong population decline, a decline that coincides with the arrival of humans in the region, 3,000 years ago, and which has intensified in recent centuries with the advance of colonization of the South Pacific islands.
The data was published by scientists at the Okinawa Institute of Science and Technology, Harvard’s Museum of Comparative Zoology and the University of Maryland in Science magazine in mid-September. The trend, according to researchers, is representative of a process that can affect endemic insects from different parts of the world and their habitats.
This is because the abundance and biodiversity of insects are crucial to maintaining healthy ecosystems, as they perform functions ranging from flower pollination to decomposition and supporting nutrient cycles. In Fiji, for example, native species are even responsible for growing coffee plants on tree bark to collect their nectar.
Insect population declines have already been identified across the world, but their extent is difficult to measure. Most studies are based on field research conducted over the past century, with gaps in understanding long-term trends, researchers say. The new study, however, uses a community genomics approach to more precisely delineate the demographic trends of species that exist exclusively in Fiji.
Thanks to existing museum collections, it was possible to trace the evolutionary relationships of ants to explore their arrival on the islands and reconstruct the population history of the species.
“Alarming” result
According to a statement from the University of Maryland, the result is “alarming”.
“The fact that endemic species are in decline is a cause for great concern, both for the future of these species in Fiji and for the possibility that this is a much more widespread phenomenon, affecting other types of insects and other islands,” said Evan Economo, one of the entomologists responsible for the analysis.
Research indicates that the A greater proportion of declines appears to have occurred in recent centuries, coinciding with European contact, colonization, global trade and the introduction of modern agricultural techniques. Meanwhile, ant species recently introduced by humans are experiencing explosive growth in their populations.
“And on islands, non-native ant species are a major problem as they disrupt local ecosystems, driving native species of all types to extinction and causing problems for human health and agriculture,” Economo said. “It is likely that the increase in non-native ant species is one of the factors why endemic species are declining as a group, along with other pressures.”
“Global insect apocalypse”
The researchers emphasize that the Islands function as microcosms of global trendsas they are isolated ecosystems that feel the effects of human impact more quickly.
“Determining whether recent observations are part of longer trends can help guide conservation efforts and identify factors contributing to the global insect apocalypse,” says the University of Maryland statement.
The researchers’ next step will be to recover molecular data hidden in museum samples to shed light on the decline of other globally important insect species.
