​

The almost constant sunshine in this area of ​​the Gulf of Lion benefiting from the Mediterranean climate is disturbed by the strong wind regimes which animate this sector. These sometimes sudden and violent winds would explain the name of the Gulf (XIIIth Century) which would come from this dangerous and unpredictable sea like the LION. The dominant regional wind is the TRAMONTANE, the cause of which is the mountainous acceleration corridor between the North of the Pyrenees and the South of the Massif Central. North-North West wind coming from the mountain ranges and blowing in the direction of the Gulf of the lion, It is cold, dry and violent. The AUTAN VENT which blows opposite the Tramontana (South East) and ARGADE which is a southerly wind generally bring clouds and rain.

The dominant current is the North Current which runs along the continental slope from the North-East to the South-West. It is more intense, narrow and deep in winter, wider and less intense in summer. Other currents are linked to the winds and cause underwater exchanges.

Surrounded by mountain ranges, this coastal geographical area is rich in rivers (Aude, Agly, Têt and Tech), coastal rivers, canals (Jonction and Robine) and ponds (BAGES-SIGEAN, LA PALME, LEUCATE-SALSES, CANET -SAINT NAZAIRE) .

The Gulf of Lion and a young passive margin fed by very active watersheds (coastal rivers) providing an important sediment flow. The continental slope is notched by numerous canyons. These canyon heads are currently disconnected from rivers, however, we know that they play an essential role in exchanges between the continent and the sea and represent "conduits" concentrating the transfers of energy and matter. This is why the canyon zone is of particular interest for the study of species living in this sector.

The Lacaze-Duthiers Canyon is also the subject of a long-term study because of the presence of large populations of deep-sea species of corals whose density and abundance are exceptional for the Mediterranean.