Las Tablas de Daimiel National Park, a freshwater wetland in Central Spain, faces another catastrophic drought period that now lasts for several years. It is another extreme hydrologic event which the wetland suffers on roughly ten-year cycles for the past 40 years. The “Llanura Manchega” aquifer, a significant source of water that fed the wetland for at least the last 30,000 years, continues to be overexploited. It no longer provides the vital water the wetland needs for survival. There are no indications that the current environmental emergency will be abated soon. There is precedence of short-sighted water management maintaining business as usual, evidenced by the last period of extraordinary rainfall (2010- 2014). In this period, the groundwater table swiftly recovered, in some areas showing a rise of up to 20 m. Management saw this rise as an opportunity to spur agricultural irrigation. This clearly conflicts with ecological goals to preserve the wetland and its important biodiversity. The pumping of water from the aquifer for irrigated agriculture continues to be excessive. Only the highly uncertain weather lottery occasionally grants water to the wetland. However, this important resource is insufficient, and rainfall is too erratic to abate the unsustainable water crisis in La Mancha region. With predicted consequences of climate change in an area where water has been traditionally scarce, due to the semi-arid climate (rainfall below 400 mm), recharge of the aquifer will likely further decrease and aggravate the environmental crisis of Las Tablas de Daimiel. The outlook is bleak.
Notwithstanding, the current situation for Las Tablas de Daimiel can be remedied, capitalizing on the wetland’s own capacity to adapt to and recover from adversity. That is, the wetland, despite the severity of accelerating human-inflicted disturbances, is still alive. With sound management it is able to “jump-start” its environmental processes and manifest its boundless ecological wealth, which is nothing short of other emblematic national (Doñana, Ordesa, Aigüestortes, Delta del Ebro or Bañolas and Sanabria Lakes) and international (the Florida Everglades, the Danube Delta, the Pantanal of Brazil) ecosystems. The wetland in its current edition no longer resembles the ecosystem that our previous generations knew and cherished. It is highly influenced by anthropogenic activity and will continue to be so in the future. But its ecological legacy is alive; aquatic plants and animals regenerate almost immediately when water is available.
The ecosystem keeps in its memory a genetic heritage that we must not lose. It is an invaluable library in which the natural history of La Mancha region and the interior of the Iberian Peninsula is written. Its biodiversity, ecological processes, and the use of its natural resources is so rich that multiple tomes can be written. Losing this ecological and cultural heritage would be like closing the Prado Museum forever. Las Tablas, Doñana, the Ebro Delta, and many others are our leading natural museums that preserve biodiversity. Even during periods of substantial environmental adversity, Las Tablas de Daimiel wetland is a refuge for more than 2,000 species (bacteria: 703, algae: 367, phanerogams: 314, sponges: 1, rotifers: 84, crustaceans: 32, insects: 276, fish: 7, amphibians: 12, reptiles: 18, birds: 213, mammals: 22). Many species are endemic to La Mancha, such as Limonium carpetanicum, others highly depend on its habitat for breeding and foraging, such as the marsh bunting (Emberiza schoeniclus), the European pochard (Aythya ferina), the red duck (Netta rufina) or the black-necked grebe (Podiceps nigricollis). With ongoing degradation of the wetland survival of their Iberian populations is at stake and may likely even end in extinction. Moreover, many critical processes conducted by microorganisms, invisible to the human eye, also occur in the wetland, providing essential services for humanity's sustainability. The removal of excess nitrogen, the transformation of organic matter, or the immobilization of greenhouse gases (such as CO2 and methane) are top-line exemplars of ecosystem services provided by the wetlands that help maintain a balanced Biosphere.
Great strides have been made in understanding Las Tablas de Daimiel scientifically. Research across all branches of the natural and social sciences has accumulated a solid evidence base about the past and present status, and it informs about potential future realities of the wetland. We have significant information about the factors that have changed the wetland: unsustainable water resource use and contamination bear the highest weight of responsibility. However, there has traditionally been a rift between the interests to, on one hand, invest in knowledge through, for instance, public funding of research projects, and, on the other hand, political interests in using the obtained knowledge for sound management of the wetland. Specifically, political interests prioritizing economic growth have held sway over the protection of ecosystems. The time is ripe for today's society, the most educated and environmentally conscious we have ever had in our history, to demand that our governments take advantage of the investment and place scientists at the forefront to solve a problem for which there are answers based on knowledge. In an age of mis-and disinformation it is crucial to echo the voice of scientists across all spheres of society to ultimately facilitate responsible governance and public education, awareness and engagement.
The signatory scientists of this manifesto state:
1) Las Tablas de Daimiel wetland is a relic of the extensive floodplains throughout the Gigüela, Azuer, and Guadiana rivers, arising from the interactions between groundwater and surface water. It is a unique ecosystem on planet Earth. As such, it has been included in treatises that provide greatest possible legal protections (National Park, RAMSAR Wetland of International Importance, Biosphere Reserve and ZEPA zone). 2) Although Las Tablas de Daimiel has proven to be a very resilient ecosystem to environmental degradation, the degree of disturbance that it can withstand is close to the limit, and it is likely that, if no action is taken, it will suffer very profound changes in its structure and function, which make it difficult to recover them in the long term. 3) Current management schemes of Las Tablas de Daimiel wetland are entirely insufficient. Political decisions must be made about its future in the short, medium, and long term. Different long-term scenarios should be considered regarding the consequences of any policy decision. Long-term planning must be the only way to reverse the current wetland degradation, preserving ecosystem values and biodiversity. Otherwise, the wetland will irretrievably disappear. Society as a whole must be aware of the environmental situation of Las Tablas wetland and should participate in this decision. 4) The disappearance of Las Tablas would mean irreparable damage to the natural wealth and cultural heritage of Spain and the planet, an irremediable loss of an unrepeatable genetic and ecological legacy, the result of hundreds of thousands of years of evolution, which can never be recovered. 5) The scientific knowledge about wetlands in general and Las Tablas de Daimiel in particular, is advanced enough to propose environmental restoration and mitigation measures that ensure their conservation and the improvement of their biodiversity and functionality in the short, medium and long term. 6) Water supply is the most limiting aspect of the ecosystem's persistence. There are no signs that the aquifer will recover its groundwater levels to guarantee a self-organizing, sustainable wetland state that existed before large-scale degradation. It is therefore necessary to ensure a regular water flow of 17 hm3 per year to ensure its ecological survival. This water supply must be completed when necessary through the Tagus-Segura river diversion, as legally established (Laws 13/1987 of July 17 and 30/2014 of December 3, and Royal Decree-Laws 6/1990 of 28 December, 5/1993 of April 16, 8/1995 of August 4, 1/2016 of January 8 and 87/2017 of December 5), while looking for other water source alternatives, both for the ecosystem and for irrigation, based on the recycling and reuse of wastewaters, the rainwater capture at large-scale or atmospheric water harvesting. For hydrogeological reasons, pumping water from the aquifer in the local wetland environment generates a limited water supply that only serves to reduce the risks of peat combustion but does not maintain wetland flooding.
For all the above reasons, the signees ask the Governments of Spain and Castilla-La Mancha Region and, specifically, the Spanish Ministry for the Ecological Transition and the Demographic Challenge to invest in Nature because that is ultimately investing in human health and quality of life. The recovery of Las Tablas de Daimiel is possible with political will and, above all, with scientific knowledge, as has been achieved in other ecosystems in the world. Ecosystems which have been more severely damaged than Las Tablas de Daimiel (the River Thames in England, the Danube floodplains in Austria, Hungary and Romania, the Dragoman wetland in Bulgaria, the Emscher River in Germany, the Camargue in France, the Florida Everglades or the Klamat River in California, among many others) highlight the power of science-informed management. The pending issue of the recovery of Llanura Manchega aquifer is not the responsibility of the primary victim, Las Tablas ecosystem. The current state of the wetland is not the cause, but the effect, of inefficient governance. Science shows that restoring ecosystems is the only solution to conserve biodiversity and stabilize the Earth's climate, keys to solving the current climate and environmental crisis. The UN has declared 2020-2030 the decade for ecosystem restoration. We still have time to make the right decisions: it will be too late in a few years.