The configuration of Mainland Portugal, located at the westernmost tip of Europe, allows it to benefit from about 800km of coastline, bathed by the Atlantic Ocean. This geographical situation also gives it the exceptional characteristic of bringing together, along the coast, species typical of both the Atlantic and the Mediterranean fauna.
On the other hand, the archipelagos of Madeira and the Azores, whose geographical characteristics are very different from those of the mainland, offer a new perspective on the Atlantic marine fauna, which already presents subtropical characteristics. Therefore, the Portuguese marine fauna is extremely diverse, being one of the country's greatest treasures.
In the saltwater galleries, the Vasco da Gama Aquarium also displays a wide variety of these species, in thirty-seven aquariums with volumes ranging between 600 and 25,000 litres. The importance given to the local marine fauna is in line with the dominant trend in the design of modern European public Aquariums, since the aim of presenting local ecosystems is fostering environmental education and encouraging the study of the biology of the species that are part of them. This is the most important contribution of contemporary public Aquariums.