European eel

22 June 2018 | Posted in Charlotte Owen , fish
European eel
eel © Derek Middleton

By Charlotte Owen
WildCall Officer

The European eel is a snake-like fish, its muscular body propelling it through the water – and sometimes over land - in a series of sinuous waves. For centuries people had no idea what this mysterious creature was or where it came from, guessing that eels were born from the mud, oozed out of the roofs of thatched cottages or were created by the action of sunlight on dewdrops. Such confusion arose because nobody had ever seen a juvenile eel – or at least, not knowingly.

Young eels look nothing like the adults and start life as flat, transparent larvae. We now know that they are born three thousand miles away in the Sargasso Sea, a remote region of the North Atlantic next to the mysterious Bermuda Triangle. It is the only sea without a land boundary, defined instead by four swirling ocean currents that together form the North Atlantic Gyre. The waters within the Gyre’s turbulent embrace are eerily still and beautifully blue. Here, the eel larvae drift about feeding on ‘marine snow’ – tiny organic particles that shower down from the surface - until they enter the Gulf Stream and begin the first leg of a mammoth migration towards the UK. Carried along by the current, they metamorphose into cylindrical glass eels, still small and see-through but growing gradually longer over several years as they drift ever closer to our shores. Eventually they will arrive at an estuary and make their way upriver on an incoming tide. As they enter the fresh water they start developing some colour and are now known as elvers. It will take at least another decade for them to grow into fully mature adults, at which point they will make the same epic journey in reverse and swim all the way back to the Sargasso Sea to spawn, and then - presumably - die.

For a variety of reasons, some still unknown, glass eel numbers have plummeted in recent years and the European eel is now critically endangered. Thankfully, now that we have a better understanding of its amazing lifecycle, we can take effective action to save this slippery character from sliding into the history books.


  • Stuart Ogden:

    27 Apr 2020 19:05:00

    On 10th April 2020 I crossed the bridge N0.0060 over the stream that runs through the woods just north of Newick and runs into the Ouse just east of the village.I looked into the crystal clear waters of the stream and noticed “weed” about 8 cm long clinging to the dead branch that had fallen into the stream.Then the weed twisted showing a silver belly and eyes. Looked more closely and there were at least a dozen or so similar sized eel like fish in the same location. Two days later I saw them again, but since then the water level has dropped and I haven’t seen any for over a week.

  • Jackie Harvey:

    29 Apr 2020 10:02:00

    I live in Willingdon, Eastbourne and have a small stream flowing through my garden.
    Part is very silty and it is here, when it rains, that eels appear. Saw one yesterday. The most I have seen together is 3- sizes vary. I do not know where the stream goes and wonder if these eels are around all the time and do not make it to the sargasso sea.

  • George Ryad:

    18 May 2020 22:20:00

    I believe that most, if not all, waterways in Willingdon flow into the network of sewers built to control the flooding of Eastbourne. There are several points along the coast where the system flows into the sea that would enable the eels access.

  • Michael Evans:

    15 Nov 2020 09:53:00

    Mill Ball Binsted, Arundel, this morning, following heavy overnight rain, came across adult, approximately 18” crossing flooded footpath between my big lake and my small pond. I haven’t witnessed this before.

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