Developers threaten animals in Croatia's cave network by Tom Heap

Species of animals, millions of years old, could be wiped out by pollution and development in Croatia, according to a new breed of cave biologists.

Jana Bedek and her team of bio-speleologists have recently discovered that the underground networks of the Balkans, especially Croatia, have the richest cave fauna in the world.

"We are now in the place with the best range of cave animals in the world," she says.

"The other countries have their own rich fauna in rainforests, marine ecosystems etc, but here in this area we have cave fauna. Really important at world level."

But on a political and economic level, Croatia is emerging from decades of communism, and the devastating Balkan war, with a desire to develop.

They are expected to join the EU in two years' time and the government has a queue of road, rail and power projects awaiting approval.

Some 41% of the country rests on the massive shard of limestone known as the Karst.

One cave known as "Vilina Spila" or Fairy Cave, boasts archaeology alongside its biology. Athenian pottery adorned with the goddess' symbol of an owl can be found amongst broken Roman amphora which litter the floor.

It is one of the biggest and most abundant caves in the Balkans, yet it is earmarked for an extraordinary hydro-electric scheme which will store water in the cave itself by sealing much of it with concrete.

'Baby dragon'

The underground ecosystem in Croatia is extraordinary in so many ways.

First, it is animals only, no plants. The total darkness means photosynthesis is a non-starter and all the creatures must live on a meagre diet of what is washed in from the surface, bat droppings or each other.

Such Spartan rations do not allow abundant life, but it is varied, including spiders, millipedes, clams, sponges, scorpions and, weirdest of all, the cave salamander.

The cave salamander looks like an eel with legs, but it has no eyes and pale, almost translucent, skin. Once seen, you can understand the belief it was a baby dragon. In fact they are not babies at all - they can live for a very long time, up to 100 years.

But it is not just aged individuals dwelling in the underworld, the species themselves are ancient too. They can claim to be the first Europeans.

Over the past 10 million years, as ice ages and deserts wiped out most life up above, caves became the bunker for existence, clinging on in the unchanging world below.

Slavko Polak, a biologist in the huge Postojna cave just into Slovenia says: "We can prove with molecular DNA analysis these lineages of animals are very ancient. Maybe the oldest surviving species in the European continent. It is not acceptable that they will be extinct from human activity."

Most of the species do not live anywhere else in the world and are unique to a particular cave network. Yet it is such a difficult environment for scientists, that bio-speleology is in its infancy.

Jana Bedek - who won a prestigious Whitley Award in 2011 for her conservation work - usually finds a new life form on each field trip and has many more awaiting classification.

Tight rules

Kornelija Pintaric, head of the Nature Protection Directorate at the Ministry of Culture accepts that, while they do their best to protect the environment, some valuable caves will inevitably be lost: "Some caves have been destroyed because of the need to build some very important national infrastructure."

But many environmentalists believe the advent of the EU is having a perverse effect.

Ms Bedek and her colleagues are convinced European Union rules would never allow plans like the one for Fairy Cave to go ahead, but she also believes that is why many developers are in a hurry to get their permissions now - before Croatia becomes a member state.

"They're rushing to have all their permits, because when we are in the European Union, it will not be possible to get them, so now is the only chance," she says.

Europe has tight rules on habitat conservation and huge swathes of Croatia are likely to be protected.

Davorin Markovic, head of the State Institute for Nature Protection says whenever you build a road tunnel there is an 80% chance of hitting a cave and even he admits developers are pushing hard right now.

"They know that there will be some restrictions [coming] so it is normal to 'catch the train when you can'," he says.

The EU's ambassador to Croatia, Paul Vandoren, says he is aware of the pressure but insists that Brussels keeps a close eye on impending projects to prevent rules being bent.