The RADIALES project is based on the systematic and continued sampling of the coastal ocean in the upwelling system of the northwestern Iberian Peninsula. Multidisciplinary observations (physics, chemistry and biology) are collected at time scales appropriate for recording oceanographic events at all seasons, thus allowing to discriminate between different sources of temporal variability.

In situ observations are made at monthly frequency in 5 transcets of stations located in Vigo, A Coruña, Cudillero, Gijón and Santander. This spatial distribution allows recording the main variabitility in oceanographic and biogeographic conditions in the west to east decreasing upwelling intensity gradient in the southern Bay of Biscay. Furthermore, local characteristics, as the differential influence of Galician rias in Vigo and A Coruña, the effect of Cape Peñas between Cudillero and Gijón, or the narrow continental shelf in Santander are taken into account.

Each transect is defined by a shelf reference station (ca. 100 m depth) and a coastal reference station (ca. 20 m depth), where detailed hydrographic profiles and water samples are made. Additional complementary stations allow to sample the local characteristics of each transect.

Sampling logistics are facilitated by the local oceanographic centres near each transect.