European Eel (Anguilla anguilla)

Of all the species in our virtual safari, few have a more extraordinary travel itinerary than European Eels. By the time they reach the Weald Moors, their larvae may have spent up to three years drifting across the North Atlantic ocean in plankton before heading, as tiny Elver, into our rivers and streams. Upon reaching maturity, they are bound to return to the coast once again, on a final journey back to their breeding grounds in the Sargasso Sea. 

ID: a long, narrow-bodied fish with a continuous dorsal and tail fin and slimy skin that changes colour with age. When eel larvae reach our shores they metamorphosise into ‘glass elver’, a name which reflects their newly transparent appearance. Once in our local waterways, their colour changes again, from yellow to silver, as they reach sexual maturity — a process that can take up to twenty years, although it is generally shorter for males. Adult eels, which can grow to one metre long before they return to the sea, are variable shades of brown, black or olive with a yellowish underbelly. If you ever happen to be walking the moors on a rain-soaked, dark moonless night, these are the conditions in which adult eels often begin their migration home.
Eel can survive on land for several hours and may even enter damp fields to feast on slugs and worms (Environment Agency)

In the Field: Eel larvae drift in on the Gulf Stream in early spring, moving inland between May and September. Wetlands and backwaters are especially desirable destinations and those with plenty of aquatic and bankside cover will generally prove attractive. Eels can survive on land for at least a couple of hours, and may even enter damp fields after dusk to feed on slugs and worms. As this behaviour might suggest, these opportunistic nocturnal predators feed on a wide variety of fish, invertebrates, and insect larvae (which are important for young eels) but, conversely, may not eat at all during the winter months.

How Are They Doing?
Owing to its geography, the west coast tends to recruit a higher influx of eels than any other part of Britain, making their journey to Shropshire a little more straightforward. While they are widely distributed in our waters, the numbers making their way to northern Europe have plummeted by around 90 % in the last twenty years. Consequently, the European Eel is the only species presently found in Shropshire that is classified as ‘Critically Endangered’ on the International Union for Conservation of Nature’s global Red List. Commercial fishing, pollution and the escalation of physical barriers on waterways are all thought to have contributed to their decline but because much remains unknown about the eel’s life cycle we do not have the full story. What we do know, however, is that because eels are slow growing and potentially long-lived (to around eighty years, although twenty is thought more likely) these losses are that much harder to absorb.
The River Strine at Crudgington Green marks the northern edge of Water's Upton Moor
On the Weald Moors: first recorded in the Domesday survey of 1086, Eels are probably the oldest documented species on the Weald Moors. At that time, renders by the thousand were taken at Crudgington and Chetwynd, reflecting the importance of eel to the local medieval economy. While the brackish peatland waters still offer favourable conditions for young eels to grow to maturity, they are no longer present on the moorlands in anything like those numbers. However, eels have been reported along the course of the River Strine on Waters Upton Moor and at the Buttery, while nearby, on the River Tern at Crudgington, a thousand year lineage of recorded sightings still continues!


Weald Moors Habitat: Rivers, Streams and Strines