The Ria de Aveiro is a coastal lagoon located in the northwest coast of Portugal, in the western Atlantic Ocean (40º38’N, 08º 45’W). It is a complex social-ecological system that lays between the marine and terrestrial domains. In terms of climatology, this region is under the influence of a temperate maritime climate with a warm period between July and September, and a cold period between December and February. The annual range of the monthly average temperature is around 10ºC. Rainfall occurs mainly between October and May, with higher precipitations in December and January. From the geological point of view, the Ria de Aveiro is a recent feature formed through the accumulation of marine and riverine sediments during the last 1000 years in a wide and shallow bay. These mechanisms have not yet attained equilibrium and the present tendency is to silt up. Much of the present-day geomorphology of the Ria has been determined by human intervention directed to counterbalance this silt-up tendency. The connection between the Ria de Aveiro coastal lagoon and the Atlantic Ocean (through a single inlet of 1.3 km long and 350 m wide) enables the water exchange and the formation of a shallow lagoon. The lagoon is approximately 45 km long, 10 km wide and covers an area of approximately 83 km2 and 66 km2 of wetland at high and low water, respectively. It consists of four main channels with several branches forming island and inner basins. The Ria de Aveiro also integrates the Vouga River estuary and the freshwater wetland Pateira de Fermentelos. The combination of the freshwater discharge and the tidal penetration creates a longitudinal salinity gradient from about 0 in the river to about 36 at the ocean entrance.

• LTER
• GOOS Essential Ocean Variables (EOVs)
  • Marine birds abundance and distribution
  • Fish abundance and distribution
  • Macroalgal canopy cover and composition
  • Marine mammals abundance and distribution
  • Microbe biomass and diversity
  • Phytoplankton biomass and diversity
  • Seagrass cover and composition
  • Zooplankton biomass and diversity