The European eel: so much more than just a fish

With the start of a new academic year, my tutor wanted to get to know his students better, so he gave us a guideline to introduce ourselves. What our 'environmental image' was, he asked. The question intrigued me. How could I choose just one image that symbolised everything that environmental science means to me?

Should I choose a photo of the Bourgoyen, the nature reserve here in Ghent where I regularly go for a walk?

Or one of the North Sea, considering my love for marine ecology?

Maybe one of a mushroom, given my fascination with underground fungal networks?

Or Knepp Estate, because of my interest in rewilding?

And suddenly I knew. It would be the photo I got from biologist Pieterjan Verhelst after I interviewed him for an article I wrote for EOS Blogs last year about eels.

Glass eel, photo: INBO

As a little girl, I wasn't particularly fond of eels. First time I saw them, was on my Dad's dinner plate at restaurant De Vette Os in Poperinge: big chunks of snake in a slimy green sauce, or so it seemed. Things didn't get better when I learned about the animal at school. A fish that could even survive on land? How weird could it get?

Perhaps it was my childish imagination that turned me to Patrik Svensson's book The Book of Eels, in which he explained all about the miracle called Anguilla anguilla.

The animal turned out not to be as scary as I had told myself as a girl. What's more: it proved nothing less than an extremely fascinating and intriguing creature. A creature that deserves pure awe.

When I decided to write an article about it and interview experts, I quickly noticed that it was an animal that also provoked intense debate. As a critically endangered species, it still ended up on the menu. Environmentalists and chefs firmly disagreed about the right approach to save the species.

And truth be told: there appeared to be no obvious solution. Removing eel from our menu wouldn't save the species. We had to look further: at water quality, physical barriers, illegal trade.

So when my tutor asked me about my 'environmental image', I decided that, for me, the eel could be symbol for any environmental issue: for its complexity, the often opposing voices in the debate, the various stakeholders.

The animal also symbolises my love for learning new things and sharing that knowledge with others.

As an organism that lives in both salt- and freshwater systems and can even survive on land for several hours, it embodies my love for all ecosystems on earth, both terrestrial and aquatic.

The eel illustrates how even the most seemingly boring species – like a mud-dwelling worm-like creature – can be truly fascinating in all its life stages – once you know about it.

The latter is essential. We know very little. With regards to the eel: even after more than 2,000 years of research, we still don't know how the animal reproduces. According to Artistotle, he spontaneously emerged from clay and mud. These days, we're pretty sure that is not the case, but as to what exactly happens... We're still guessing.

This ignorance is quite general. It is a well-known cliché that we know more about Mars and our Moon than about our own deep sea. Estimates of the number of species on Earth range from 3 to 100 million. And while we are already making plans to mine the seabed, we don't even know which species live down there and what their role is in the bigger ecosystem.

There is so much to discover still.

Concluding: the eel mainly symbolises my deep awe for nature. With glorious life stages called 'willow larva' (in Dutch, that is. In English we just say Leptocephalus...), 'glass eel' and 'silver eel', it can only appeal to the imagination. The adults dissolving their stomach and, without additional nutrition, crossing several kilometers of ice-cold water to reproduce once and then die, is nothing short of majestic.

I mean... Not bad as my 'environmental image', right?