Bass are present in Europe, encompassing both native populations and introduced species from other continents. These include a prominent native marine fish and several freshwater species that have established populations across the continent.
The European Seabass: A Native Presence
The European seabass (Dicentrarchus labrax) is a native marine fish widely recognized in European waters. It has an elongated body, silvery-grey to bluish coloration, and a silvery underside. Adults reach about 50 cm, with some growing up to 1 meter and weighing 12 kg. Young seabass display dark spots that fade as they mature.
European seabass are predatory, feeding on small fish, prawns, crabs, and cuttlefish. Juveniles consume invertebrates, transitioning to a fish-heavy diet as they grow. This species holds cultural and economic importance across Europe, being a popular target for both sport fishing and commercial aquaculture. It is a key cultured fish in the Mediterranean, with Greece, Turkey, Italy, Spain, and Croatia as major producers.
Freshwater Bass Introductions
Beyond the native European seabass, other “bass” species, like the North American largemouth bass (Micropterus salmoides) and smallmouth bass (Micropterus dolomieu), have been introduced into European freshwater systems. These introductions were deliberate, mainly for sport fishing due to their popularity.
Largemouth bass have a large, sloping mouth extending past the eye and a laterally compressed, olive-green body with a dark stripe. Smallmouth bass have a more streamlined body and a smaller mouth, with the upper jaw not extending past the rear half of the eye. They are olive-brown with dark mottling. Both are predatory: largemouth bass consume fish, crayfish, and frogs, while smallmouth bass feed on insects, crayfish, amphibians, and other fish.
Where Bass Thrive in European Waters
The European seabass is widely distributed across the Eastern Atlantic (Norway to Senegal), and throughout the Mediterranean and Black Sea. It inhabits coastal waters, estuaries, and brackish lagoons, tolerating a wide range of temperatures (5-28 °C) and salinities. Adults spend winters in deeper offshore waters, migrating to shallower coastal areas and river mouths during summer. Juveniles form schools, using estuaries as nursery habitats before moving offshore.
Introduced freshwater bass species, such as largemouth and smallmouth bass, have established populations in various European countries. Largemouth bass prefer slow-moving, clear freshwater environments like lakes, ponds, swamps, and river backwaters, often seeking areas with dense vegetation for cover. They can tolerate some brackish water conditions, with salinities up to 13 parts per thousand.
Smallmouth bass typically thrive in cooler, clearer waters, including rivers with gravel or rocky bottoms and the rocky shoals of lakes. Their distribution within Europe often aligns with areas that provide suitable thermal conditions, such as the southern half of the continent where mean July temperatures exceed 18°C. While smallmouth bass have been introduced to several European countries, their establishment has not always been successful in all locations.