Arjan Palstra

The females, they have to produce many eggs, so they have to be big and fat.

And that takes many, many years in order to reach that stage.

So imagine like a male is on average maybe 40 centimeters, while a female can be 80 centimeters a meter.

It really has to be big.

The bigger and older, the better.

Finally, they returned to their birth grounds in the Sargasso Sea.

They spent like 10, 20, 30 years in order to become as big and as fat in order to be able to do that.

After swimming 5,000 kilometers, they spawn and they die and the whole cycle starts again.

So there is still a huge gap in their life cycle and then particularly the oceanic part.

This creates all kinds of problems.

So for the European eel population has been in decline between the 1980s up to 2010.

Wow.

And it's very difficult to find out which are the exact causes and what we can do about it and how we can manage the population.

We do not even know how many eels leave to the Sargasso Sea every year.

And on the other hand, for aquaculture, it's important to artificially reproduce eels, but we still cannot.

Also because we completely lack a natural reference.

We know what's happening in the lab, but how normal or natural that is, we have no idea.

Yeah, from every two or three years, there is a cruise organized by the group of Heinold Hanelt.

So basically they spent several weeks in the Sargasso Sea trying to catch larvae.

I've never joined one of their cruises.