The network of Núria Salvador, pushed methodically, for a timed period, through the bottom of the temporary pond of Vale Santo, near Vila do Bispo, surrendered two copies of Vicentinus Triops, a species of tadpole shrimp that is endemic, that is, unique in this most southwestern region of mainland Portugal.
O Vicentinus Triops it is even considered a living fossil, as it has persisted since the time when dinosaurs appeared (between 199 million and 145 million years ago). And this kind of tripods it only exists on the Costa Vicentina.
The two copies collected in the raid made in the pond are already quite large, one with a carapace measuring a little more than five centimeters, the other less than four.
But the redactions made by the scholarship holder Núria and the researcher Margarida Machado on a rainy February afternoon also allowed the capture of a huge salamander with protruding ribs (pleurodeles waltl), some tiny fairy shrimp and shell shrimp, insect larvae, black nail toad tadpoles (Cultripes), and a multitude of other creatures that live in that small pond.
"If it were a year ago, we wouldn't have any of this here," said Margarida Cristo, a specialist in crustaceans and another researcher on the University of Algarve team participating in the LIFE+ Project “Conservation of Temporary Ponds on the Southwest Coast of Portugal”. "There was a ditch here, opened by the previous tenant of the Vale Santo property, to drain the pond, and the water would not accumulate." This, despite the temporary ponds being considered priority habitats and to be protected in the Natural Park of Southwest Alentejo and Costa Vicentina…
It's that, despite the speed with which they complete their life cycle - from the eggs hatch, through the growth phase, adult phase and reproduction phase - the rare Vicentinus Triops they didn't even have enough water in the pond to live on.
«Not long ago, after we presented the problem to the mayor of Vila do Bispo, during a visit we made to this pond and in which he participated, the Municipality ordered a machine to come here, which, in two hours, closed the ditch. It took ten years to wait, but finally the pond was filled with water again», told Margarida Cristo, to the report of the Sul Informação.
And, with the water, life returned, exuberant, to the small temporary pond, which is now covered with plants, some of which are typical of this habitat, and teeming with fauna. In the case of large branchiopods (which include tadpole shrimp, fairy shrimp and shell shrimp), their eggs survive for at least ten years, waiting for water and appropriate temperatures to hatch and return to life.
The Vale Santo pond is just one of about a hundred temporary lakes already identified in the Southwest Alentejo and Costa Vicentina. One of the tasks of the LIFE Charcos Project is, precisely, to identify and map all those that exist in that Site of Community Importance. «By the end of the project, in December 2017, more may appear. At the end of last year, we discovered four more near Rogil, unmarked by anyone, who were recommended to us by a German who lives in Aljezur», reveal the researchers.
Margarida Cristo and Margarida Machado still remember with emotion the day when, in 1996 – 20 years ago now – they discovered that, in these swamps of the Portuguese Southwest, in Pinhal de Sagres and Vale Santo, there was also tripods, these tadpole shrimp that are real living fossils. Only in 2010 was it confirmed that here there is a unique species in the world, which was named “Vincentian” in honor of the Costa Vicentina.
This small prehistoric survivor became better known to the general public last year, when television reports made known the existence of yet another unique species on the Southwest Coast.
But it is not just because of the strange tadpole shrimp that these habitats are of great ecological importance and must be preserved.
Mediterranean temporary ponds constitute one of the most remarkable and unique freshwater habitats in Europe and are considered a priority habitat by Annex I of the Habitats Directive.
In addition to playing an important role in connectivity between other freshwater habitats, the diversity of life in a temporary pond is very high and even higher than that found in other aquatic environments, such as permanent ponds or watercourses. . Many of the species they harbor are considered rare and threatened, both at European and global level.
Margarida Machado points out that, "in the southern part of the Natural Park, there are more ponds that are better preserved than in Odemira, where 50% of the ponds disappeared in the last ten years due to the great advance of intensive agriculture." The destruction of ponds to make way for agriculture, especially greenhouses, is, in fact, one of the greatest threats to the survival of these habitats.
“The legislation defines temporary ponds as priority habitats and to be preserved. But the truth is that, for many years, little was known about them, not even known how many there were, in fact. The Natural Park and the ICN, which should have surveyed the ponds, did not. Only now is that being done», adds Margarida Cristo.
The production of georeferenced cartography of the ponds and the biodiversity associated with them is, in fact, one of the most important tasks of the LIFE Charcos project.
“The problem is that when subsidies are given, for example, to an agricultural crop, the area occupied by the ponds is discounted and the farmers are not compensated for it”, explains the researcher. Therefore, it was easier for farmers to drain the ponds and make them disappear, as it almost happened in Vale Santo and as it certainly happened in many other places.
Hence, underlines Margarida Cristo, it could be important to create compensation measures…but, for now, namely through the demonstration of sustainable management practices of these temporary ponds and increasing public awareness of their value and need for preservation, which is intended to involve landowners, farmers, decision-makers and other stakeholders. At least so that no one can say they destroyed it because they didn't know…
In fact, among the threats already identified by LIFE Charcos are the changes in agricultural and livestock practices, with the intensification and fragmentation of the habitat (today there are ponds that even remain, but surrounded on all sides by the plastic sea of greenhouses , the impoverishment of associated Biodiversity, forestry activity, tourist pressure, climate change (with less rain, ponds are disappearing), and, so often, the simple lack of information and ignorance.
In this task of making ponds and their ecological importance more (re)known, there are precious allies, such as schools. Hence the big bet that the project has made in Environmental Education. At EB 2,3 in Vila do Bispo, students and teacher Beatriz Oliveira transformed an old cement pond into a temporary pond, already inhabited by many of the emblematic species of this habitat.
Elsewhere, it has been with the help of volunteers and the effort of the project team members themselves that some ponds are being restored.
This is the case of the Torre de Aspa pond. Last year, the acacia trees that nearly smothered the small temporary pond were cut down and uprooted, freeing up ample space around it. “We took tons of plant matter from here, especially acacia trees, which are an invasive species,” recalls Margarida Cristo. Precious help was given by the Algar company, "which offered part of the disposal and treatment of the pulled up acacias", and by the Vila do Bispo Council, "which offered the truck to transport the plants".
Less than a month ago, project partners linked to the University of Évora were at the site to plant some shrubs, such as myrtles and oleanders, which are part of the typical vegetation of these areas.
Without the invasive acacia choking it, the pond is regaining its health. But there is still a lot of work to be done, not least because the acacia roots left in the ground are already bursting and, if measures are not taken very soon, these plants will quickly invade everything again. “We have to organize an action, perhaps with the help of volunteers, to make known the importance of ponds and bring people here to help us uproot these roots,” says Margarida Cristo.
The recovery of ponds is also one of the project's objectives, through the demonstration of management and restoration techniques that improve their conservation status.
Another example of recovery is the Pena Furada pond, which happens to be located on land that even belongs to the Vila do Bispo Council. This is one of the places that researchers from the University of Algarve visit regularly, to record various parameters, such as the pH of the water, temperature, dissolved oxygen and also turbidity (water color).
Wearing a fisherman's waterproof suit, with built-in boots, the student Núria and the researcher Margarida Machado enter the pond, carrying several instruments in their hands.
With her sleeves rolled up, Margarida Machado immerses a digital thermometer and shouts, to whoever, on the bank, takes note of the data collected in each pond: “the temperature is 13,3º. Look, it's already down: it's 13,2º».
Beside him, dipping a graduated ruler in the water, Núria Salvador communicates other data: «the height is 62 centimeters on the ruler». Soon after, excited, she comments: “Hey man, it's gone up a lot! If I remember correctly, I was in my early 50s». The rains these past few weeks have been generous for the temporary ponds and for all the life they harbor.
Núria is the project's hydrogeologist, in charge of investigating the hydrogeological behavior of the temporary lagoons. It is already known that these ponds arise in impermeable terrain, capable of retaining water. But there are ponds that only start filling up long after it starts to rain. How is it explained? One possible answer is that the water level is influenced by the water table and waterlogging by rain. To find out more, piezometers were installed in some ponds, in holes with probes where the fluctuation of the water level is measured. The same happens outside the ponds, in the surrounding area, «to understand if the land is waterlogged or not» and «how all this dynamic is processed», explains Núria.
One of these piezometers is installed in a field where sheep graze. When Núria Salvador goes there to collect the data, he verifies that it is not working. In a conversation with the elderly farmer who owns the herd, he comes to the conclusion that the ram thought that the tube where the device is located, which protrudes from the ground by tens of centimeters, was good for scratching itself… Result: breakdown.
Despite the setback, the investigators like to talk to the farmer. «He says that he has always lived here and already knew the pond. But when we showed him the life that exists there, he was amazed. We have gained a supporter of our project and the protection of the ponds», guarantees Margarida Cristo.
And one of the goals of LIFE Charcos is precisely that, at the end of the four and a half years of the project, many other followers have been won for the cause of protecting this unique, important and sensitive habitat.
Some interesting data
LIFE Charcos is a project coordinated by the League for the Protection of Nature (LPN), which has a partnership with several public and private institutions, namely the University of Évora, the University of Algarve, the Municipality of Odemira and the Association of Beneficiaries of Mira.
This project is financed 75% by the LIFE-Nature Program of the European Commission, with an overall budget of around 2 million euros.
The LIFE Charcos Project will last for four and a half years, between July 2013 and December 2017.
The LIFE Charcos Project is being implemented in the Site of Community Importance (SIC) of the Southwest Coast of the Natura 2000 Network (partially coinciding with the Natural Park of Southwest Alentejo and Costa Vicentina), more specifically in the moors of the municipalities of Odemira and Aljezur and plateau Vila do Bispo, because there are some of the main temporary ponds at national level.
Learn more about LIFE Charcos Project by clicking here.
Photos: Elisabete Rodrigues|Sul Informação
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