From River to Sea: The Epic Journey of European Eels

European Eels (Anguilla anguilla) in Deptford Creek, London, are part of an exciting conservation story. The Creek, an urban waterway in southeast London, is a tributary of the Thames and has historically been subject to industrial pollution and encroachment into the river. In the 1950s there were no fish living in the Thames in inner London. Since then, it’s become home to diverse wildlife, including European Eels. In recent years, environmental and conservation efforts have been made by the people at Creekside Education Trust and other groups that have improved the quality of the waterway to support aquatic species like the European Eel.

The life cycle of European Eels is complex and spans many years. Eels begin their lives as larvae in the Sargasso Sea, a region of the Atlantic Ocean. These larvae, known as Leptocephali, drift for several months with ocean currents before reaching the European coasts. During their migration, they transform into juvenile or "glass eels" and migrate into freshwater rivers and estuaries. Over several years, they mature into adult eels, gradually darkening in colour. When ready to spawn, adult eels embark on a journey of epic proportions, spanning thousands of miles to return to the Sargasso Sea, where they die after laying their eggs, completing the life cycle. However, more information is needed about their exact migration patterns or routes. Which is the main reason this species is so mysterious.

Here at The Creek, we have the perfect habitat for European Eels. The eels enjoy fresh or brackish waters near the coast during adolescence. While in freshwater, they spend most of their time in the mud, waiting in an ambush for food. They typically eat bottom feeders, small invertebrates, or even fish. This means if they are present in an ecosystem as a predator, they are a positive indicator of a healthy food chain. Especially as they are critically endangered. Some juvenile eels found in the Creek have measured over 30cm. This is a promising population indicator, as most adult eels grow to around 50 cm, with the largest being around 70. 

The diverse ecosystems of Deptford Creek make it a unique local environment, not just for wildlife but also as a space for community engagement and ecological education. With ongoing conservation work, Deptford Creek plays a significant role in London’s natural heritage. However, this requires lots of time and work to preserve and uphold the local environment. Creekside always appreciates support from people coming to our events or those subscribing to our newsletter and following social platforms, as well as being open to donations or volunteers and help in whatever shape or form that takes. 

- This blog post on European Eels was written by Howie, and Joshua took photographs. Howie and Joshua have recently completed their work experience at Creekside Discovery Centre.

The image of the deceased eel was sourced from Creekside Discovery Centre photographic archives.