UNESCO Marine DNA Surveys Expand to Track Biodiversity in Remote Southern Ocean Sites

Researchers are returning to those four locations as part of the expanded seven-site campaign in 2026, creating a basis for examining changes in marine biodiversity and checking for newly recorded species.

Scientists are expanding environmental DNA sampling in the French Southern and Antarctic Lands (TAAF), using traces of genetic material collected from seawater to document marine life and track changes in some of the world's most remote ecosystems. The 2026 campaign covers seven sites, including four surveyed in 2022, allowing researchers to compare findings over time and investigate whether species previously undetected at those locations are now present.

The work forms part of eDNA Expeditions, a citizen science initiative studying marine biodiversity and the effects of climate change in UNESCO marine World Heritage sites, with sampling carried out at 21 sites since 2018, including places that are difficult to reach through conventional research expeditions.

Water samples reveal marine life without disturbing animals

Every marine organism, from microscopic plankton to whales, releases genetic material into the surrounding water through waste, mucus and shed cells, leaving traces that scientists can analyse to identify species without capturing or disturbing them. Environmental DNA, or eDNA, analysis uses these traces to build a picture of the organisms present in an area, complementing traditional surveys and reducing the need to collect samples directly from animals.

The method has particular value in the French Southern and Antarctic Lands, near Antarctica, where a harsh climate makes a permanent human presence difficult, large distances separate the archipelagos, and supply ships arrive only about three times a year. These conditions limit opportunities for fieldwork, making a method based on water collection useful for gathering biodiversity information from locations where repeated, extensive surveys are difficult to organize.

Seven-site campaign builds on findings from 2022

The first phase of the TAAF project surveyed four sites in 2022 and detected 181 species and 418 taxa, a broader term for groups of organisms sharing common characteristics, with the higher taxa count reflecting detections that could not all be identified to species level. Researchers are returning to those four locations as part of the expanded seven-site campaign in 2026, creating a basis for examining changes in marine biodiversity and checking for newly recorded species.

Sampling began in the Crozet Archipelago in October, placing the collection of local biodiversity evidence alongside international discussions about how countries are progressing towards their commitments to protect nature. The campaign coincides with the UN Biodiversity Conference, CBD COP17, in Yerevan, Armenia, where governments are conducting the first global review of progress under the Kunming-Montreal Global Biodiversity Framework.

Accessible monitoring can fill gaps in ocean knowledge

Monitoring marine life remains difficult in places that few people can visit, and the relatively low cost and non-invasive nature of eDNA sampling make repeated surveys more feasible, offering researchers a way to build knowledge over time rather than rely on isolated observations. The approach also creates opportunities for citizens and early-career researchers to participate in scientific work, broadening involvement in the collection of information needed to understand and protect marine ecosystems.

The second phase could improve detection of emblematic or poorly documented animals, including marine mammals, sharks and rays, as well as indicator species associated with vulnerable marine ecosystems. By extending sampling and revisiting established locations, the project will contribute shared knowledge about biodiversity in sites recognized by UNESCO for their outstanding universal value, supporting a clearer understanding of how these remote marine environments are changing.