The eel's mammoth journey
Post categories: autumnwatch,Ìýfish,Ìýmigration,Ìýriver,Ìýwater
| 10:05 UK time, Thursday, 9 October 2008
When I was a boy messing about on the River Taff (at the weir just near the Millennium Stadium) I remember distinctly finding a tiny eel, but at the time I wasn't sure what it was. It was in fact a juvenile eel called an 'elver'.
Unknown to me it had just made the journey all the way from the Sargasso Sea (south of Bermuda) and now it was in my hand, measuring only eight centimetres or so.
Eels are one of the truly great animal mysteries. No-one has ever witnessed or found them spawning. It's puzzled people for many years: Aristotle thought they came from rotting seaweed and even Sigmund Freud kept one to try to find out the answer.
It has been deduced that they spawn in the Sargasso Sea and make their way across the Atlantic as tiny creatures using the oceans currents such as the gulf stream.
They then travel up rivers, climbing weirs and other obstacles to make it to into the river system, an incredible effort for such a small fish.
They will spend most of their lives in fresh water and grow in size until it comes to the time when as an adult eels (now a pretty hefty creature) start heading downstream (and across land even) and head out into the ocean to start the journey back to the Sargasso Sea.
This will be one final journey to spawn and start the cycle again.
All epic stuff, and in an age of technological advances where people communicate each others' locations using a raft of devices, it's amazing to think that we still don't really know where the eel goes on its journey.
So why am I talking about them now? Well autumn is the time when the adults start their journey and start moving out from the rivers out to sea. It's dependent on rainfall and the stages of the lunar cycle but across the country they are starting their long and final swim.
On a more sober note over the last 20 years there has been a 90% reduction in the population abundance in Europe and this is serious news for our slivery tourists.
There are a number of factors involved: netting, fishing and barriers to migration, not to mention possible disruption from climate change to the currents that bring them across the Atlantic as young.
It is also sad to think not everyone likes eels. Another recollection I have was the attitude from a minority of anglers who took a dim view of eels and persecuted them for tangling their lines up. It's a practice I hope has stopped.
Like many things in wildlife they are inspirational and I'd like them to not go the same way as salmon and disappear from some of our rivers. Best of luck Eels - have a good trip.
And here's a sneak piece of information for you: we hopefully should be meeting some conger eels in this year's Autumnwatch, these huge sea creatures can reach up to three metres long - watch this space!
Comment number 1.
At 13th Oct 2008, yruri21 wrote:I didn't know that eels are disappearing at that rate. I thought they're everywhere. One of my friends told me that he caught three eels in a river in his neighborhood (,which is in Japan,) and kept them for a year in a plastic wardrobe box but never had a chance to see them spawn. Finally he felt sorry for the eels and let them go where they had been. I wonder if eels in Japan also travel to Sargasso Sea in autumn...
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