Conger Eel

Encounters with European congers typically occur during daytime reef or wreck dives, where they rest inside crevices, harbour walls, or artificial structures like wreck funnels. During the day, divers usually see only their broad heads sticking out from shelter. At night, congers emerge to hunt across open reefs and the water column.

When observing a conger, maintain excellent buoyancy control and keep hands well clear of its lair. Large congers possess powerful jaws and sharp cutting teeth capable of inflicting severe bite injuries if startled, cornered, or provoked. Never attempt to feed or touch a conger; hand-feeding is extremely dangerous due to their aggressive feeding response. Use dive lights cautiously, avoiding direct beam exposure on their eyes for prolonged periods. Maintaining a respectful distance ensures safe and natural interactions.

European congers are non-migratory during their juvenile and subadult phases, remaining resident in coastal waters year-round. Divers can consistently spot them across British, Irish, and North East Atlantic dive sites during winter, spring, summer, and autumn without seasonal drops in local abundance.

Seasonal changes primarily relate to reproduction, which occurs far outside recreational diving depths. Adult congers undergo spawning migrations into deep offshore waters. Studies suggest that spawning in the Mediterranean takes place during the summer months, specifically between July and September. Because females undergo a single semelparous spawning event in deep water and die afterwards, shallow inshore dive sites are populated by resident juveniles and immature individuals, providing reliable year-round sightings for scuba divers.

The European conger is widely distributed throughout the eastern Atlantic Ocean, extending from Norway and Iceland southwards to Senegal, as well as across the Mediterranean and Black Seas. In Britain and Ireland, it is most abundant along the southern and western coasts of England, Wales, and Scotland, and around the entirety of Ireland.

Conger eels inhabit rocky coasts, broken reefs, harbour walls, and artificial structures like shipwrecks. Juveniles and younger congers reside close to the shoreline in shallow waters, while larger adults gradually move into deeper offshore areas. Their depth range spans from shallow intertidal areas down to 500 metres in regular feeding grounds. During reproductive migrations to offshore Atlantic and Mediterranean spawning sites, mature individuals descend into extreme oceanic depths ranging between 600 metres and 4,000 metres.

The European conger is a nocturnal carnivore and opportunistic predator that feeds primarily under the cover of darkness. While it remains largely inactive in dark rock crevices or wreck cavities during daylight hours, it emerges at night to actively forage across rocky seabeds and throughout the water column.

Its diet consists mainly of bony fish, cephalopods such as octopuses, and various crustaceans including crabs. Congers are efficient hunters of live fish, using their strong jaws—which feature an outer row of large cutting teeth and an inner row of smaller, sharp teeth—to seize and overpower prey. In addition to actively hunting live animals, congers are known to scavenge opportunistically on dead and decaying fish on the seafloor. This combination of active nocturnal hunting and scavenging allows them to maintain a robust diet across diverse temperate marine habitats.