Open data on cetaceans in France: where to find it

France has one of the largest maritime seaboards in the world, and with it a substantial body of scientific monitoring of cetaceans and marine mammals. A large part of these data is public and freely accessible, in particular on the data.gouv.fr portal. Here is a guide to the main sources for anyone who wants to explore, check or reuse them.

data.gouv.fr, the public data portal

data.gouv.fr is the official open data platform in France. It holds hundreds of datasets on marine biodiversity, published by public bodies. The main contributor on cetaceans is the Office français de la biodiversité, with more than 1,400 environmental datasets.

The Office français de la biodiversité (OFB)

The OFB publishes many monitoring datasets: surveillance programmes for the marine nature parks, heritage-value indices for cetaceans by season and by marine subregion (Manche-mer du Nord, for example), home ranges of the common bottlenose dolphin (Tursiops truncatus), or the monitoring of the coastal bottlenose dolphins of the English Channel (GECC project, 2022-2025). These map layers feed knowledge of the distribution of species along the coast.

The Réseau National Échouage (RNE) and the Observatoire Pelagis

Run by the Observatoire Pelagis (CNRS / La Rochelle Université), the Réseau National Échouage has recorded cetaceans stranded on the French coast since 1970. An extract from this database, covering the marine nature park of the Gironde estuary and the Pertuis sea over the period 1971-2016, is available on data.gouv.fr: it counts strandings by species (common dolphin, long-finned pilot whale, harbour porpoise…). To be cross-checked with our interactive map of strandings.

The SAMM campaigns (Suivi Aérien de la Mégafaune Marine)

Led by Pelagis, the SAMM campaigns fly over French waters (mainland and overseas) to estimate the abundance and distribution of large marine animals, including cetaceans. The effort and sighting data (for example winter 2011-2012 and summer 2012) are indexed on data.gouv.fr. Standardised monitoring of abundance is also carried out from coastguard patrol boats.

The Atlas des mammifères marins sauvages de France (MNHN)

The Muséum national d’Histoire naturelle published the first volume of the Atlas des mammifères marins sauvages de France in 2016. The occurrences by species (2000-2015), aggregated by INPN grid cell on the Atlantic and Manche-mer du Nord seaboards, indicate where each species has been observed at least once.

IFREMER and the marine strategy

IFREMER contributes to the indicators of the Marine Strategy Framework Directive (DCSMM), which assesses the good environmental status of European waters, including the distribution of marine mammals and turtles. The Cerema, for its part, publishes presence indices (for the common bottlenose dolphin, for example) useful for offshore wind studies.

For whom, and for what?

These data are addressed to researchers, but also to teachers, to students and to curious members of the public. Cross-referenced with our own tools, population demographics, sighting hotspots, marine protected areas or citizen science, they help to understand concretely where French cetaceans live, how their populations are changing and what threats bear on them. And anyone can contribute: by reporting a stranding to the RNE, or by submitting their sightings to participatory platforms.

Sources: public datasets of the OFB, the MNHN, the Observatoire Pelagis, IFREMER and the Cerema, indexed on data.gouv.fr (accessed June 2026).