National Nature Reserve of the Bay of Somme

The National Nature Reserve of the Bay of Somme protects one of the most significant coastal wetland systems in the Hauts-de-France region of northern France, covering the mudflats and salt marshes at the mouth of the Somme river where it meets the English Channel.

How did this reserve come to be?

The protected area has its roots in a national hunting reserve established in 1968. It wasn't until 21 March 1994 that the site was reclassified and formally designated a national nature reserve, shifting its purpose from hunting management to conservation. Today the reserve covers 3,421 hectares, forming part of the much larger Bay of Somme estuary system, which spans roughly 7,000 hectares in total.

What makes the Bay of Somme so distinctive?

The Bay of Somme ranks as the second-largest estuarine complex on France's north-western coast, surpassed in size only by the Bay of the Seine. Its landscape is defined by tidal mudflats (vasières) and salt marshes (prés salés) that are regularly submerged and exposed as the tide moves in and out twice a day — a rhythm that shapes both the terrain and the wildlife found here.

Why is this a magnet for birdwatchers?

Birds are the main reason the Bay of Somme has earned international recognition among naturalists. Positioned along major migratory flyways, the reserve serves as a critical stopover, wintering ground, and breeding site for waterbirds and waders. More than 300 bird species have been recorded here over the years, representing around 65% of all bird species found across Europe. That figure places the Bay of Somme among the richest birdwatching sites on the continent, drawing both researchers studying migration patterns and visitors equipped with binoculars.

Seals, rare plants, and other natural treasures

Birds are far from the only draw. Over the past three decades, additional ecological values have come to light. The Bay of Somme is home to France's largest colony of harbour seals, which haul out on the sandbanks within the estuary. The reserve is equally notable for its rich and rare flora: 727 plant species have been catalogued to date, with 176 of them newly identified since 2016 alone — a sign that scientific surveys of the area continue to turn up new discoveries.

What should visitors know before coming?

The reserve sits within Hauts-de-France, close to several tourist towns that ring the bay. Because the site is a protected natural area, exploring the mudflats and salt marshes is best done with a guide or along marked paths, allowing visitors to observe birds and seals without disturbing their natural behaviour. The landscape itself changes constantly with the tides, so the same spot can look markedly different depending on when you visit — worth factoring into any trip planning.

Frequently asked questions

When was the reserve established? It received official nature reserve status on 21 March 1994, though the land had already been protected as a hunting reserve since 1968.

How large is the reserve? It covers 3,421 hectares within the wider Bay of Somme, which totals around 7,000 hectares.

How many bird species can be seen here? More than 300, roughly 65% of all bird species found in Europe.

Do seals live in the reserve? Yes — it hosts France's largest colony of harbour seals.