Exploring the Arcachon Bay Marine Park in France

Source: The Daily Catch/Nils Sommer - July 10, 2015 in Environment, News

Exploring the Arcachon Bay Marine Park in France
Photo: Nils Sommer

On February the 26th, the “Parc natural marine du bassin d’Arcachon,” a marine protected area, was officially installed in the Arcachon Bay on the Atlantic coast of France. 435 km2 of marine surface and 127 km of coastline are now under protection by a state funded management board, representing environmental groups, fishermen, oyster farmers, pleasure boaters, tourism authorities, and local residents. The main objective of this structure is to protect this rich and unique marine environment, while maintaining sustainable economic activities for fishermen and tourists alike.

The first management plan will be developed within the next two and half years and shall set the priorities for the next 15 years to come. With an annual budget of 2 million Euros and a staff of about 20-25 employees, the management will have solid resources for scientific studies and development guidelines.

Above all, the “priority of priorities”, will be the water quality, François Deluga, newly elected chairman of the management board, pointed out in an interview for the French magazine “20 Minutes.” Other measures, discussed by the board, could include the reintroduction of certain fish species, or the cleaning of the oyster banks.


Photo: Nils Sommer

The port in the city of Arcachon has become the second largest marina on the French Atlantic coast, hosting around 12,000 boats between 6 and 8 meters, most of which are motorized. With this staggering number of boats in this relatively small area, moorings on seagrass, typical for the Arcachon Bay, are becoming more and more destructive on this benthic ecosystem.

The Zostera seagrass meadows have extensive root systems, which both stabilize the sediments and store very large amounts of carbon. They also shelter larvae and juveniles of many commercially important fish, shellfish, and crustaceans, and are the habitat of the enigmatic seahorses. Zostera beds typically occur in clear water on sand or mud substrate. The plant is physically not very robust and its roots can easily be dislodged by dredging, trawling nets, or anchors being hauled across the sea floor, as an OSPAR (Convention for the Protection of the Marine Environment of the North-East Atlantic) report from 2009 concludes.

Designating anchoring places with prefixed corkscrew moorings to reduce the physical degradation of seagrass within the bay could be an example for one of the first regulatory efforts of this new appointed board, explains Pierre Leca, director of the public agency overseeing all French marine protected areas.

But he also notes, that one of the main roles of the park is to raise public awareness about marine environmental issues. The park is unique in its location and faces real challenges. “It is the opposite of an island, a piece of water encircled by land. The maritime world is surrounded,” says Pierre Leca.


Photo: Nils Sommer

Augmented run-off from the populated littoral washes lots of nutrients and pollutants into the bay, which can lead to an increased turbidity caused by eutrophication. Another factor that has been linked to declines in seagrass abundance, as light penetration is reduced and prevents adequate photosynthesis in deeper water. Also, harmful toxic algae blooms may occur, that can contaminate the oysters. In the past, this has already led to the prohibition of oyster sales for several weeks, for example in the summer of 2006, as an Ifremer report states.

But with the right management and good education of the locals, fishermen, and tourists alike, these threats on the natural marine park can be curtailed.

Thanks to its overseas territories, France has the second largest maritime area in the world under its jurisdiction with about 11 million square kilometers, behind only the United States. This presents France with an enormous opportunity, and some would argue responsibility, to make a global impact on ocean conservation.

France is answering the call with an ambitious goal to protect 20% of its waters by 2020, as was decided in the Grenelle Environment Conference in Paris 2009, a political debate between government, industries and NGOs.

From 2010 to 2015, France already designated seven natural marine parks. The marine park in the Bay of Arcachon was the sixth step in this anticipated series of ten. The seventh park, in the Gironde Estuary, was just established in June 2015, while three more are still undergoing studies.

Nils Sommer



Nils Sommer studied Biology (BSc) and Marine Environment and Resources (MSc), with an emphasis on marine biology. His master thesis consisted of a research term in the well known Shark Lab in the Bahamas. He’s passionate about the protection of sharks and the fight against the devastating over-exploitation of many marine species.

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