'The quality of the sea water in Malaga province is excellent'

Francisco poses for the interview on the Misericordia beach in Malaga city.
Francisco poses for the interview on the Misericordia beach in Malaga city. / MARCOS ÁLVAREZ
  • "The scum is floating foam formed by pieces of clay which have been cleaned from the sands," he says, and he assures us it is innocuous

Life is better by the sea. That commonly heard phrase is often applied to the Costa del Sol and Francisco Franco Duro would undoubtedly agree. Maybe it's the salty smell or the movement of the waves. Maybe the fascination comes from the unknown. The eye deciphers what it sees in front of it, but the depths continue to hold great mysteries. Francisco has dedicated his whole life to the scientific study of the sea and knows more than most about it.

Ulysses, Treasure Island, Robinson Crusoe and Moby-Dick. Literature always seems to present the sea as something violent and dangerous.

The sea is capable of everything positive when it is calm and makes us feel happy, but when it is rough it is the most dangerous thing we can come across. Sailors have a huge respect for the sea.

Your whole scientific career has been dedicated to studying the sea. What is it that fascinates you about it?

The ability to create life. Even though we don't look after things properly, the sea always makes up for it. If we leave the ecosystems which have been damaged by humans in peace, they recover at an incredible speed. That ability to cure others and also cure itself really impresses me.

In the end, humans have always ended up returning to the sea.

Because it is the origin of life. It feeds human beings, and not only with fish. It feeds on every level. The sea is a connection between cultures. It is entertainment for us. It is a tremendously important part of people's lives in towns and villages along the coast. In Malaga we have always had the feeling of living with our backs to the sea. That perception is changing now.

Is the sea still a great unknown?

The sea is still very much a great unknown. We know about the life that exists on the part which is nearest the surface. Imagine the surprises we would find if we did a sweep of what there is really deep down. Especially because of the diversity of marine species in the deepest areas.

What influence does the depth of the sea have on us?

The depth makes a big difference. We can't see what is down there and that makes swimmers afraid. There is always that uncertainty, thinking about what might be below.

Is Asian algae the biggest threat for our coast right now?

It is one of the serious threats that we face. It is notably affecting the quality of the coast. On the Costa del Sol, which is the area that concerns us, it is causing damage from Manilva to Mijas and also in the Nerja area. If this residue, for example, gets onto a meadow of posidonia it stops it doing the photosynthesis it needs to survive. It also means people can't swim there.

When did we realise that the sea could also be used for fun?

In the mid-20th century we started to use our sea for leisure and sport. Nowadays people don't just see it as somewhere to work - they realise that it is also there to be enjoyed.

Why do people in Malaga province say the beaches of Cadiz province are the best?

Personally, I don't envy Cadiz for its beaches. I look at them from a scientific point of view. The beaches in Cadiz have a very homogeneous grain size. The sand there is sand. The grain size in Malaga province is not homogeneous, it is very heterogeneous. The sand in Malaga is not just sand. We have particles of gravels and particles of silt and clay, which are what cause the dust.

Have travel agencies convinced us what the perfect beach should look like?

Of course. We have a stereotype of the perfect beach, where the sea is turquoise and transparent and the sand is very white. These beaches practically don't exist anywhere in the world. A lot of the photos have been retouched.

What is the quality of the sea water like in Malaga province?

I can understand that someone who sees the water is cloudy, due to the clay and silt sediments suspended in it, might not be sure about the quality, but that uncertainty is based on what they see. And the eye can be deceptive. As scientists, we can only follow the data that we obtain in the laboratory. The sea water in Malaga is excellent quality. On the Costa del Sol, the sewage plants we have throughout the province mean that we can enjoy sea water free of fecal microbiology.

What causes the scum? Is it harmful?

The scum is floating foam made by the bits of clay that have been cleaned from the sands. When a scum has formed, it starts to collect marine components. Those minerals retain micro-algae and any marine microbiology. If they find a feather, for example, they hold on to the feather. In the end, the scum is a collection of particles which are mostly of mineral origin, a quantity of micro-algae and a certain amount of marine microbiology. It is always natural, we have never found fecal microbiology in it.

What do you think about the sewage situation on the Costa?

We have the infrastructure that we have and we use it to make sewage disposal as effective as possible. The fact that we have found excellent quality sea water in the 50 places we have analysed shows that the system is working well. That may not be the case in rural areas.

Is there a symbiosis between humans and the sea?

We take a great deal from the sea and we give it very little in return. It's not a symbiotic relationship. Humankind exploit the sea, on every level. In the past few years, however, there has been concern over how to make the sea more sustainable.

Which beach would you recommend as being good to live beside?

That's a difficult question, with so many to choose from. Maybe the beaches in Estepona. The area is not too built-up and the sea there is very interesting for diving.