Eels are making a comeback to the region
PUBLISHED: 14:37 12 July 2014 | UPDATED: 15:41 12 July 2014
Eels are making a comeback to the Fens, with more of the snake-like fish slithering their way up our rivers and drains than have been seen in years.
Eels were once so common in the Fens that they were both an important food source and a form of currency.
The stones to build Ely Cathedral were paid for in eels, while the name of the city where the Ship of the Fens stands itself means Island of Eels.
Hundreds of years ago, many believed eels grew from the hair of dead sailors. Compleat Angler Isaac Walton reckoned they sprang from the sun on dew drops.
Over the last century, scientists have pieced to gether their incredible long-distance migration from our shores to the Sargasso Sea off Bermuda and back.
Over the last two decades, experts say numbers of young eels arriving on our shores have fallen to just 5pc of those seen in the 1980s.
Conservationists feared the species could face extinction within a generation. Eel fishing has all but ceased. Anglers are banned from taking them for the pot.
Some blame shifts in the Gulf Stream for the catastrophic decline. Others a parasite which attacks the swim bladder, meaning the fish plunge to the bottom when they attempt to swim across the continntal shelf.
Eel management plans are now in force. Fish passes are being built to help them migrate past the barriers we have placed across our waterways, like sluices, locks and weirs.
Any reverse in their decline is not just good news for eels and eel anglers, but for our rivers all round. Eels are an important food source for predators as diverse as the otter, heron and the pike.
Officials say “exceptional” numbers of elvers have been recorded at the St Germans Pumping Station, near King’s Lynn.
The young eels - around three inches long and the thickness of a shoelace - have travelled thousands of miles from the Sargasso Sea, off Cuba, to spend their lives in Fenland waterways.
A special fish pass has been built at St Germans - Britain’s biggest pumping station - on the Middle Level Drain, to help elvers ascend the sluices.
The first eels were seen using it this Spring. Some 10,000 were recorded during the first three days of April, while 50,000 were counted in the first three weeks of the month.
Cliff Carson, chief environmental officer with the Middle Level Commissioners, which manage the Middle Level drainage system, said: “It’s great to see a boom year for elvers after so many years when their numbers were less than 5pc of former totals returning to the UK.
“We hope this trend will continue. The St Germans Pumping Station elver pass will give excellent access for eels and elvers into the Middle Level rivers and drains that will benefit eel population recovery in the future.”
From St Germans eels can travel far inland along the network of drains and dykes whicch stretch across the Fens. Some are even believed to migrate overland on moonless nights, to reach landlocked waters.
Eels are omnivorous, eating everything from invertebrates to small fish and frogs. After spending around a decade in freshwater, by which time they can be as thick as your arm and weigh in excesss of 5lbs, the adults set off on their journey back to the Sargasso, where eels from around the world gather to breed.
In recent years, eel numbers have seen a steep decline. Some blame a parasite which attacks the creatures’ swim bladder - the organ fish use to control their swimming depth.