I NEVER cease to be amazed by the wonders of Mother Nature. Just when you think you understand her whys and wherefores, she does something completely unexpected. Take the population of eels inhabiting the River Thames, for example.
Eels have been a part of the ecology on the river for centuries – jellied eels were a traditional dish in the east end of London for years and the humble eel also gave its name to a number of familiar river features including, most obviously, Eel Pie Island in Twickenham.
So I think we should all be a little worried by news that the eel population in the Thames has mysteriously fallen by about 98 per cent in the past five years.
I’ve spoken to a number of fishermen who tell me that in previous years eels were a regular catch but these days they are about as common as hen’s teeth. And ecological experts fear that the sudden and unexplained disappearance of the eels could have a knock-on effect for other river species.
How do we know about this decline in the eel population? The Zoological Society of London (ZSL) records the numbers each year by capturing eels in traps and then releasing them again.
The story of the how the eels have populated European rivers is, itself, absolutely fascinating. They start life as larvae in the Sargasso Sea – an area of the North Atlantic Ocean that is bounded by four major ocean currents. The baby eels are believed to take up to three years migrating to European rivers where they live for up to 20 years before making the journey back to the Sargasso to spawn and die.
Dr Matthew Gollock, tidal Thames conservation project manager at ZSL, said: “Eels are mysterious creatures at the best of times but we are very concerned about the rapid disappearance in the Thames. It is difficult to say what is going on – it could be due to a number of potential factors including changes in oceanic currents due to climate change, man-made structures such as dams and the presence of certain diseases and parasites.”
And he said there was a need to find out why the declines were happening, in order to save the eels and help other species in the estuary’s food chain that would be affected by their disappearance, including birds that feed on the creatures.
Jellied eels, served in Pie and Mash shops, is made up of chopped eels, boiled in a spiced stock that is allowed to cool and set, forming a jelly and can be eaten hot or cold. These days most eels used in Pie and Mash shops now come from Holland or Northern Ireland.
THANKS for the response to my request for helpers with the Spelthorne Civic Pride Thames litter pick. Organiser Jill Stephens was delighted with the turnout and the group of nearly 40 volunteers managed to collect more than 70 bags of assorted rubbish including several coconuts, a pair of y-fronts (yeugh!) the broken halves of a plastic dinghy, hundreds of plastic bags and bottles and the left leg of a mannequin! Well done to all.