Biodiversity gaps challenge species protection

Scientists trying to track biodiversity decline say they are being held back by major gaps in data on the world's species, a problem expected to feature at the UN COP17 biodiversity summit in Armenia.

The challenge is illustrated by Pocota personata, a bumblebee-like insect last seen in France 150 years ago and spotted again in the Paris region in 2025. Scientists do not know whether it disappeared and returned or simply went unnoticed.

In France, the National Museum of Natural History and the National Centre for Scientific Research launched a project in June to build a database of the country's plants and invertebrates. Rodolphe Rougerie, head of the Dynabiod project, said scientists know biodiversity is declining but often lack enough data to quantify it.

The scale of the unknown is large. A 2011 study estimated that 86 percent of terrestrial species and 91 percent of marine creatures had not yet been formally described. In 2025, the International Union for Conservation of Nature had assessed the extinction risk of only about eight percent of known species.

Researchers use field observations, insect traps and DNA analysis, but they need strong reference databases to identify what they find. Fanny Kratz, a researcher at the National Museum of Natural History, said artificial intelligence can help analyse data only if the information it is trained on exists.

Scientists also need comparable data collected across places and time. Rougerie said sparse or inconsistent monitoring can lead studies to reach conflicting conclusions about the same species, weakening the scientific message about biodiversity loss.