Sea-level rise in the Bay of Biscay and its impacts on the coast

The challenge

Sea levels are rising in the Bay of Biscay, a phenomenon linked to global climate change that is attracting increasing attention. This rise can amplify the impact of flooding caused by spring tides and storms. It can cause significant damage to ports, seawalls and seafront promenades, and threatens beaches and estuarine ecosystems.

The solution

AZTI combines sea-level data monitoring with future projections for the Basque coast. It has also conducted studies for Ihobe on the effects of climate change on the coast. These studies assess impacts on beaches and estuarine ecosystems such as salt marshes and seagrass meadows.

The results

• Detection of a sea-level rise of 1.5 to 3.5 cm per decade since the 1990s.
• A projected rise of between 50 and 65 cm along the Basque coast by the end of the century.
• An estimated rise of around 25 cm in the Basque Country by 2050, with a 16% loss of beach area.
• Identification of estuaries as affected ecosystems. Salt marshes and seagrass meadows are important for biodiversity and as blue carbon sinks.
• Key information to identify sustainable solutions for mitigation and adaptation.