Data from expert interviews

Interview with Juan Ramón Fernández Cardenete  and Juan Salvador Santiago Cabello  - 16/2/2023

• What does it mean for a basin to be endorheic?

Well, as in the case of the lake originating in the Padul peat bog, an endorheic basin means that it is not fed by a river, so it is internal and is fed by groundwater, runoff from the mountains and rainfall.

• Why does it rain more in the peatland than in the rest of the surrounding areas?

Because the precipitation coming from the south and the Atlantic does not meet a mountain range or any kind of elevation before reaching the Sierra Nevada, where it collides with the Natural Park and precipitates in Padul, which is at the foot of Sierra Nevada. Even so, it doesn't rain so much any more, and in fact there were some fires in December.

• What is the origin of the lake?

This is an old peat bog, so what you saw was a black hole (from the peat which is black). The lake was not there before, when the exploitation ceased and the engines stopped working everything was flooded in a few months and you can't get the water out to extract the fish.

• What is special about the area to create the conditions for the formation of a wetland?

The wetland was formed because the Nigüelas geological fault split and the existing reed bed merged with it. That is why there is a depression of approximately 20 metres that was later exploited as a peat bog.

• Have you detected any eutrophication due to agricultural activity?

Not because of agricultural activity in particular, but it could be because there are some adjoining farms with orchards, although in reality they do not have a sufficiently important activity to cause a significant contribution of nutrients. What is really causing eutrophication in the wetland is the discharge of water from the Padul sewage treatment plant.

• What organisms are there that are indicators of the good or bad state of the water?

For example, there is anoxic sludge (an indicator of hypertrophic water, where there is no oxygen or life) in the area of the Fuente del Tío Miguel, which, as we have already seen, is very likely to be contaminated due to the bad smell. 

Above all, bioindicators of good water quality can be identified, such as melanopsis (an endemic aquatic snail with a very specific ecological niche), otters, zooplankton and some amphibians such as frogs.

• Are there any wells that may have lowered the water table?

There are some wells that are known to be extracted, most of them illegal of course, but they do not lower the water table because the wetland is quite deep. Wells will not be a big problem until there are greenhouses, as is the case in Almería.

• In your wetland project you worked on 21 different sites, is there any particularity that you remember from Padul that was not present in the others?

You have to take into account that it is the main reed bog in Europe and the most southerly in Spain, which makes its conditions special. The fact that archaeological remains of mammoths were found makes this wetland of great historical importance, because they were also found in the Russian steppe. In addition, there are some endemic species that are quite unique. For example, the shoveler duck is rare to find, and cormorants are a much more coastal bird, but, because of the humidity, they are here, making a greater biodiversity possible.

• We are going to do the recommended route, 6.3 km long. What do you recommend we look out for?

The birds above all, which is what makes the ecosystem more particular. The spoon-billed duck, herons, wood pigeon, marsh pigeon...

• In the time you have been researching the peat bogs, have you observed that visitors may have caused any negative changes in the environment?

There are times when you find remains of sandwiches, albal paper, towelettes... Also, in the high mountain wetlands there are starting to be microplastics from textile fibres because people bathe, and this affects this wetland because the water that arrives also brings microplastics with it.

• Do you think that the current legislation for the regulation and conservation of peatlands is sufficient? 

My opinion, based on my knowledge of the species, the situation and the legislation that is in place, is that whatever law is imposed is never enough. People do not comply with the regulations that are imposed because they usually do not get caught or turn a blind eye. It is also true that many towns don't even have a sewage treatment plant, and Europe sanctions Spain a lot for dumping waste, but the fines are not large and they are not respected.

• Does the lagoon dry up in summer? If so, what happens to the aquatic fauna?

It does not dry up because of its depth, so the aquatic fauna is maintained.