The Doñana Natural Space (National and Natural Park) has three dominant ecosystems: dunes, beaches, and marshes. Its geographical position gives rise to a rich biota at a major stopover point in birds’ migration routes and at a very important site for wintering waterfowl. Because of this, Doñana has acquired the highest protected area categories that a natural area can receive from international conservation organizations. Yet Doñana’s ability to support biodiversity is under constant threat due to its proximity to culturally and economically critical locations. The greatest external problems center on agriculture and tourism, which extract enormous amounts of groundwater which then alter hydrological dynamics. Excessive nutrients, roads, commercial navigation, pilgrimages, and several programed projects are additional pressures that could be aggravated by climate change. Inside the Space, overpopulations of domestic and wild ungulates, pathogens, and invasive species have changed its ecology. Doñana is managed by two operational programs implemented by a committee of 60 stakeholders. Both areas have been divided into conservation zones and very recently have been included in an extension of the old Biosphere Reserve with a Core Area (National Park), a Buffer Area (Natural Park), and a Transition Area. In the past 40 years, Doñana has received about US$900 million: this has increased not only conservation efforts in the area but also the economic level of local residents. Conflicts are lessening but pressures are mounting. More collaboration between administrations, more active local participation, more firmness concerning illegal activities, more expert technical advice, and more funding will be needed in the near future to preserve this unique natural heritage.
This case study is aimed at college students who want to study environmental European problems in depth. Doñana could be the most important wetland area in the European Union, but even so it is under such a high degree of pressure that its conservation has become a nightmare for both politicians and its managers. Students will see different kinds of environmental pressures here, some due to its long history of human occupancy, others regarding its geographical position (i.e., estuary) or the great number of people living nearby. The Doñana Natural Space probably manifests the whole catalogue of human pressures that a natural area can be under Europe. Thus, studying these conservation problems can give students a good background for understanding European environmental problems.
In contrast to the Americas, Europe has been occupied by technological western cultures for thousands of years by people who have had a long time to leave their mark upon the land. Consequently, fewer natural areas remain in Europe than in many other regions, and there are fewer opportunities to manage them in a semi-pristine state. The challenges of managing the remaining natural areas are great, as relatively small remnants exist in a matrix dominated by humanity.
The Doñana Natural Space in Spain plays a critical role in biodiversity conservation and is embedded in a matrix of intensive human occupation. Doñana is unique in many respects: as a major stopover point on the migration route of birds moving between Europe and Africa, as the home to many endangered species and it also contains perhaps the most significant wetlands in Europe. Yet Doñana’s ability to support biodiversity is under constant threat due to its proximity to culturally and economically critical locations. The Doñana Case Study is a typical example of conservation–development conflicts, but in this case, the contrast is more pronounced: exceptional biodiversity values vs. great human pressure. This involves an enormous challenge for scientists, managers, and society in general with respect to its long-term conservation.
Location and Description
The 122,488 ha in the Doñana Natural Space (Andalucía, southwest coast of Spain) comprises two administrative areas: the National Park (54,252 ha) and the Natural Park (68,236 ha) (Figure 1). It has a sub-humid Mediterranean climate  with three dominant ecosystem types : dunes (phytostable, semistable, and live or moving dunes) containing more than 3,000 temporary ponds that vary greatly in size and hydroperiod , beaches (current and relicts), and marshes (alluvial and tidal). The live or moving dunes, which run parallel to the coastline for 30 km, are the most important in Europe . The marshes, with winter water depths up to 1 m and little to no water during summer, are fed by direct precipitation and surface runoff from a network of seasonal streams, and are relatively isolated from the main Guadalquivir River. The broad ecotone between the marshes and uplands (the “Vera”) has a complex vegetational structure and great faunal diversity, including many herbivores and predators.
Biogeographical Importance of Doñana
Doñana’s geographical position, between the European and African continents and between the Atlantic Ocean and the Mediterranean Sea (Figure 1), has given rise to rich flora and fauna, recording some 898 species of vascular plants, 23 species of fish, 11 of amphibians, 21 of reptiles, 397 of birds, and 30 of mammals . The area is especially critical to bird diversity, as some three-fourths of all European species are found in Doñana . More than 600,000 waterbirds use the area for wintering or in migration to and from Africa , constituting one of the most important sites for wintering waterfowl in the Western Palearctic .
Many Doñana species of ecological interest are endemic, threatened, or otherwise endangered. This includes several terrestrial  and aquatic plants , an endemic cyprinodontid fish (Aphanius baeticus), the Moorish tortoise (Testudo graeca), 16 species of birds including the Spanish Imperial Eagle (Aquila adalberti), the only European species of mongoose (Herpestes ichneumon), and the Iberian lynx (Lynx pardinus).
This rich natural area means that Doñana is one of the most prominent wetlands in Europe, which was acknowledged by the Spanish Government when it was declared a national park in 1969 and an International Biosphere Reserve in 1980. It was also deemed a wetland of international importance by the Ramsar Convention in 1982 and a World Heritage Site in 1994. The Council of Europe also awarded the area with five European Nature Diplomas for Protected Areas (the last one in 2010). Furthermore, in 1988, the National Park was declared a “Special Zone for the Protection of Birds” which implies that it is also a part of the Natura 2000 Network established by the EC Habitat Directive 92/43.
Human habitation in Doñana dates back to before 3000 B.C. . All the great European civilizations have passed through and occupied this area, including Tartessos, Phoenicians, Greeks, Romans, Visigoths, and Arabs. Prior to 1262, the area, controlled by Arabs, was used for the grazing of cows and Arabian horses . After conquering the region in 1262, the Christian King Alfonso X established a hunting area in Doñana. In 1628, the introduction of cattle began a new phase . Growing interest in forest development led to a forestry phase, which reached its maximum activity with the introduction of pines in 1737, the principal component of the forest today.
Modern scientific interests began in the 1950s, with expeditions led by Guy Mountfort . At that time, Doñana was seriously threatened by government forestry and agricultural initiatives, and these scientists asked many international organizations for their assistance. In 1964, the World Wildlife Fund (WWF) bought 6,794 ha in the Doñana area, establishing its first protected area, the Doñana Biological Reserve. In 1969, the central government created the Doñana National Park, and in 1989, some areas surrounding it were protected by the regional government, creating the Doñana Natural Park. Since 1992, the two areas are managed together and known as the Doñana Natural Space (Figure 1).
Conservation and Management Problems
Doñana is surrounded by 46 villages and towns (including two big cities, Seville and Huelva) with a total population of about 1.5 million people. Additionally, the area is located at the mouth of the Guadalquivir River whose basin is inhabited by more than 4 million people. This human pressure generates both external and internal threats requiring active management.
The biggest conflicts center on agriculture. The beginning of the conservation phase coincided with the agricultural development of lands surrounding Doñana, reducing 80% of the original marshy surface area . Large hydraulic works around Doñana directly influenced water flow within the Space. Natural canals have been cut, blocked, or transformed. Presently, about 11,000 ha of greenhouse crops (mainly for strawberry production) in the Almonte-Salt Marsh Sector extract 109 hm3/year of groundwater for irrigation. Besides this legal irrigation, illegal extractions are common in the area, due to its approximately 1,000 illegal wells . In the past 20 years, groundwater extractions have reduced flow rates in streams that feed the marsh to 50% of historic flows and about 3,000 ha have recently been deforested in the headwaters to allow for new cultivation . All these activities are contaminating the aquifer, lowering the water table and altering the natural hydrological dynamics of the marshland and other superficial wetlands, thus increasing the length of the dry period and changing the chemical composition of its waters .
On April 25, 1998, part of the dike of a tailing pond collapsed at the “Los Frailes” zinc mine, located in Aznalcóllar. The accident released about 4 hm3 of acidic water and 2 hm3 of mud rich in toxic metals into the Guadiamar River whose waters flow into Doñana , representing the second largest tailing spillage to have occurred worldwide in the last decade . Although cleaning efforts removed more than 98% of the sludge pollution, it is still pervasive in the upper 30 cm of soils and remains a diffuse source of pollutant, which may release significant levels of toxic metals back into the ecosystem for a long time, perhaps centuries . Strangely enough, the Regional Government recently passed a research project to reopen the mine, including the enlargement of a dam for industrial and electricity demands.
Matalascañas, a beach village created in 1960 to stimulate tourism, has become a major urbanized area with about 80,000 people visiting each summer. Major impacts of tourism include the lowering of the water table, coastal organic pollution, and the straying of domestic animals into the parks. Domestic cats invading the lynx’s habitat were the probable cause of a feline leukemia virus infection detected in six lynxes that died in a 6-month period in 2007 .
The numerous roads that have been built since 1960s have improved transit through the parks. However, these roads fragment habitats and are a primary source of mortality for many Doñana vertebrates .
Another negative impact on the Doñana National Park has its origin in the cultural aspects of the area, especially in a religious tradition centered in the nearby village of El Rocío, where pilgrims have gathered annually since the sixteenth century to celebrate the Virgin of Rocío pilgrimage. Initially, this was a local celebration, but today it is a national event. This festival lasts 1 week, during which more than 1 million visitors arrive in a variety of transports, including nearly 250,000 horses . Diverse groups of “brotherhoods” use traditional roads to get to the village. About 80,000 people and 9,500 motor or animal-drawn vehicles used one of the traditional roads inside Doñana during 2015 (Figure 2) . One of the biggest problems is that this activity takes place during one of the most sensitive times of year in the National Park, during the spring, when many birds are breeding.
Navigation in the Guadalquivir River toward the port of Seville constitutes another environmental problem due to both riverbank erosion and continuous dredging. At present, there is a large and environmentally dangerous project programed to deepen the navigation channel in order to accommodate more and bigger vessels going to Seville. In spite of the negative opinion of the scientific community , the Port Authority has not abandoned this project; this is one of the main reasons for the warning issued by the World Heritage Committee about including Doñana on the List of World Heritage in Danger .
Finally, Doñana receives air pollution input from a chemical hub and from an average of 32,211 vehicles/day traveling on the Seville–Huelva highway, less than 30 km from the National Park . The sources of pollution for groundwater and surface water are the residual pollution of the Aznalcóllar mine accident along with nutrients and agrochemicals from agricultural and urban areas surrounding the Space .
In 2016, a new threat related to gas extraction and gas storage emerged. Two projects outside of the Natural Space, but inside the Biosphere Reserve boundaries, have been approved by the Regional Government . Without a doubt, this will harm natural life in the area.
At the time, this article was concluded (June 2017), a raging fire broke out during the night of 24th June in the village of Moguer (Huelva). Strong winds (60 km/h) quickly rekindled the fire which burnt about 8,500 ha in three days; most of this surface is within the limits of the Natural Park [29, 30]. The fire is now under control. All evidences point to human culprits. The risk of fires in the Natural Space increases as we approach a new drought cycle.
Negative effects on terrestrial vegetation due to the overpopulations of wild boar and red and fallow deer are multiplied by the 2,500 horses, cows, and sheep living inside the park due to the traditional rights held by local people to use the pastures . This is considered to be responsible for the introduction of bovine tuberculosis into the Space .
The appearance of two enzootic viral diseases, myxomatosis and rabbit hemorrhagic disease, have had devastating effects on the European rabbit population, killing about 95% of the original population . These events have produced dramatic changes in predator populations because of the keystone character of the rabbit .
The abundance of waterfowl in Doñana was exploited by hunters for centuries until the hunting ban in 1983. This led to the spread of lead (Pb) shot pellets in different areas inside the Space. These pellets are ingested by birds as grit, with the consequent risk of Pb poisoning . Pb shot has also had an impact on raptors that ingest the metal embedded in the flesh of their prey .
Between 1958 and 1979, crop area surrounding Doñana increased from 49.8 to 80.2% . This, along with the deficient depuration of waste water, introduces an enormous amount of chemical and organic nutrients into the Space. Moreover, pharmaceuticals have detected active compounds in the wastewater and surface water of Doñana, representing another ecotoxicological risk to aquatic organisms [38, 39].
Cyanobacterial toxic blooms and avian botulism have produced at least 18 events of fish and bird mass mortalities since 1973; the latest were in 2001 and 2004 when 1,000 and 6,000 birds, respectively, died in 2 weeks due to the presence of cyanotoxins in the food web . Simultaneous action of high temperatures during a long period (June to September), high solar radiation, and high levels of nutrients in the few remaining bodies of water contribute to such mass mortalities .
Non-native invasive species have markedly changed the ecology of Doñana. The most spectacular effect has been due to the intentional introduction of red swamp crayfish (Procambarus clarkii) in 1974 . The success of this introduction has been amazing, reaching an annual harvest in the Guadalquivir marshes of about 5,000 tons. Nevertheless, this presence has had a severe impact on the whole marshland ecosystem including the Park . Different exotic species of copepods, crustaceans, and snails have been introduced by ballast water or on the hulls of vessels , including the Chinese mitten crab (Eriocheir sinensis), an invasive species that has severely impacted the San Francisco estuary in California .
About 36 exotic plant species have been detected inside or surrounding the Park , including the river red gum (Eucalyptus camaldulensis) purposely introduced in 1940. The mosquito fern (Azolla filiculoides), a floating pteridophyte, was detected for the first time in 2000  and by 2007 had covered 4,363 ha of Doñana marshlands . Seven of the 23 fish species inside Doñana are non-native and dominant in the ichthyofauna of the Park. Carp (Cyprinus carpio), mummichogs (Fundulus heteroclitus), and goldfish (Carassius sp.) account for more than 94% of the biomass . The Florida turtle (Trachemys scripta elegans) has settled in several lagoons after being released by owners around 1996–1998 .
All these external and internal problems may be aggravated by the effects of climate change. In this century, an increase of 2°–4°C in mean daily temperature is predicted for the Doñana area, along with a reduction of about 110 ml/y in rainfall and a 0.5 m rise in sea level . This will reduce soil moisture, increase water stress, concentrate pollution, and worsen overexploitation of the aquifer . All these forces will work synergistically, increasing the threats to biota in the area.
Measures to Protect Doñana
There are two general programs to protect the Doñana Natural Space: The Ordenation Plan of Natural Resources (PORN) and The Use and Management Plan (PRUG) . The former identifies every habitat, species, ecological process, conservation problem, subsidiary program, and general conservation objective within the limits of the Doñana Natural Space while the latter develops specific management objectives to preserve its integrity. These plans are implemented by The Participation Board of the Doñana Natural Space, a committee of over 60 people who represent local, regional, and national stakeholders. The area belonging to the National Park has been divided into four zones: (1) Reserve Zones, areas containing natural values of the first order restricted to managers, researchers, landowners, and other authorized people. (2) Zones of Restricted Use, consisting of areas that are steeped in nature and able to withstand a certain level of public use. (3) Zones of Moderate Use, consisting of areas dominated by a natural environment with a higher capacity to accommodate more visitors than the above-mentioned cases. (4) Zones of Special Use, small areas with buildings and facilities. The Natural Park is divided into three Zones: A, B, and C. Although their conservation values are lower, they are managed similar to the three previously described. Doñana’s permanent staff is composed of 140 people, of whom 75 are forest wardens.
Both the flora and fauna of Doñana are managed to preserve native species and protect threatened populations. The densities of ungulates (red deer, fallow deer, wild pigs) and foxes are being controlled, and several of the plants introduced are being eradicated. Two management programs focus on the most visible and charismatic species in Doñana: the lynx and the Imperial Eagle. Both programs are mostly oriented toward habitat improvement (which will benefit many other species), the increase in the rabbit population, and captive breeding.
The plans also try to reduce the riverbank erosion produced by maritime traffic; improve terrestrial and aquatic connectivity; increase the quality of water going into the Park; promote the automatic control of environmental parameters; and promote the control of domestic animals (rats, cats, and dogs). It also promotes an early prevention program for infectious illness and the control of those existing in the park. There is also a very considerable fire control program.
The management plan allows the Space to be used by local residents for such traditional resource extraction as extensive cattle grazing, beekeeping, and the harvesting of one species of mollusk (Donax trunculus) on the beach, and of pinecones in the forest; angling is also allowed at the beach. A public use program provides visitors with information about the National Park and defends its need for conservation. Eight reception centers have been built at various points to inform visitors about Doñana’s history and natural riches. The plan also contemplates the conservation of rural architecture.
A series of outreach activities is attempting to improve the relationship between the Natural Space and residents in surrounding areas. These activities include environmental education programs in neighboring villages and the establishment of information points concerning the Space.
Future of Doñana
Will Doñana ultimately be saved from the human pressures exerted on it? What will its conservation status be when it passes to the next generation?
At the end of the 1980s, Doñana had serious conservation problems. Conflicts abounded between the conservation of natural areas and increases in economic activities. Local people felt that the National Park was holding back the economic development of the area. This led the Regional Government to create an International Committee to evaluate the situation . The report sets the guideline for The First Sustainable Development Plan for Doñana’s Neighbouring Areas (US$350 million), which clearly failed in environmental objectives but undoubtedly increased the quality of life for people in the Doñana Region . The second phase (US$195 million) started in 2010 and is still in effect.
After the Aznalcóllar toxic spill, two big restoration programs were conducted in the region: the Guadiamar Green Corridor  and the Doñana 2005 Restoration Program . These two programs invested about US$160 million in the area. Now both have terminated relatively successfully.
Recently, the original Doñana Biosphere Reserve designated by the UNESCO has notably increased its extension to 268,294 ha . The Reserve includes three areas: the Core Area of 54,680 ha covers the totality of the National Park, the Buffer Area at 58,614 ha covers the Natural Park, and finally, there is the Transition Area at 155,000 ha (Figure 3). All the three areas comprise the totality of the Doñana District where the utmost efforts will be made to protect biodiversity in the area.
In spite of all its conservation problems, in 2010 Doñana was awarded the renewal of its European Diploma, a good indicator of effective management. In 2014, Doñana was included among the first IUCN Green List areas in the world . Additionally, the enquiry of the UNESCO World Heritage team carried out in January 2015 concluded that the state of conservation was satisfactory and the values for which the site had been inscribed under the World Heritage and Wetlands Conventions were still in place .
In the past 5 years, 500 scientific papers have been published about Doñana, and in 2015, there were 94 research projects in the area; the system is now better known. Management programs are contributing to the recovery of many endangered species and several extirpated species have returned to Doñana. There is a specific recovery program for the rabbit population which in 2015 released more than 7,000 healthy specimens in the area . Marshlands are being reconnected with the main river which will help toward the recovery of tidal processes and all associated species.
In addition to the foregoing, there are innumerable environmental education courses, communication, and social participation activities and volunteer groups. Thirty-four authorized companies offer activities for the more than 300,000 visitors/year offering many job opportunities, thus helping to overcome the former aggressiveness of the local people toward the Natural Space.
Doñana’s ability to support biodiversity is under constant threat due to its proximity to culturally and economically critical locations. Thus, it has serious conservation problems, both external and internal, that jeopardize its future in the short/middle term. It is a typical example of conservation–development conflicts, but this time in an iconic European protected area. Focused collaboration between international, central, and regional governments, more active local participation in environmental decision making processes, more expert technical advice , more firmness with illegal activities and, of course, more funding are basic ingredients needed to preserve this essential natural heritage.
CASE STUDY QUESTIONS
Different projects are programed in the Doñana area: the reopening of the Aznalcóllar mine, gas storage, and gas extraction, the deepening of the Guadalquivir channel. Some managers, facing political pressure, which in turn are affected by social pressure given that the area is an economically depressed area, argue that all of them are outside the Natural Space (although inside the Biosphere Reserve limits!) and that they are backed by very thorough environmental-impact studies: thus, there are no reasons to be worried. Do you think these projects will affect the Doñana Natural Space? What is your opinion about allowing such human activities within the limits of a Biosphere Reserve even though outside its core zone?
Agricultural conflicts in the area are continuous, especially those related to groundwater extractions. In some areas, groundwater levels have decreased up to 6 m, affecting the hydrology of the Space. If things continue as they are now, the future of the Natural Space is threatened; at the same time, if farmers do not have water, their survival also is under threat. Some local farmer collectives, speaking contemptuously, say that their survival is more important than “four ducks or two lynxes”. What do you think?
Doñana is surrounded by over 10,000 ha of irrigated lands whose water comes from the aquifer. These extractions are altering the hydrological system of the Natural Space: for instance, some permanent lagoons in the past are now seasonal. The near future is not very favorable: climatic change predicts a reduction of about 100 mm/year in rainwater for the area. A great deal of negotiation is necessary to avoid the collapse of Doñana. Nevertheless, every decision regarding the management of water implies high social and political costs and politicians do not like stirring up this hornet’s nest. So, the most common procedure is to resolve the most urgent problems day by day. Discuss the advantages and disadvantages of this procedure from social, political, and conservational points of views.
Water inside Doñana has been historically managed to preserve waterfowl, regardless of effects on the autochthonous aquatic biota. In the specific situation of fish, this management has favored the proliferation of exotic species, and thus 7 out of the 23 fish species listed inside Doñana are non-native and dominant in the ichthyofauna of the Park. Carp (Cyprinus carpio), mummichogs (Fundulus heteroclitus), and goldfish (Carassius sp.) account for more than 94% of the biomass. What arguments would you use to change these trends? What is your opinion about what the general objectives for a National Park should be to preserve the whole, complete biodiversity of the area or just specific (and very interesting) segments of it?
Recently (June 2017), a raging fire burnt up about 8,500 ha, most of them in the Natural Park. Most of the tree layer affected is composed of pines, which were introduced into the area in 1737. If you were to restore this burned area on a limited budget, would you replant pines (rapid growth and cheap) or would you try to recover the autochthonous forest composed mainly of cork oaks and different undergrowth species (slow growth and expensive)? What would the environmental and social benefits of each of these two options be?
Carlos Fernández-Delgado was the principle researcher, data collector, and author of this case study paper.
The author has declared that there are no competing interests.