**4. The first considerations of the islands as a natural protected area**

All the described impacts generated several conservation problems on the natural habitats and on flora and fauna species of the island territories, constituting a threat to their long-term maintenance. These consequences, and fundamentally those derived from the presence of uncontrolled people in the archipelagos, were detected and denounced in the local media and several publications, so since 1975 Vigo municipality started various proposals for the declaration of the Cíes Islands as a natural protected area. ICONA was also developing at that time an inventory of the areas that could receive the declaration of one of the categories of natural protected areas established in the then current Law 15/1975 [33], and Cíes islands were the first proposed area in Pontevedra province. So the situation was completely favorable, and finally, in 1980, the Cíes Islands were considered as a Natural Park, in order to "preserve such an exceptional place and the need to properly condition it so that it could be enjoyed and admired by present and future generations. Its beauty was joined to the presence of very interesting colonies of seabirds that nested in the islands, such as the European herring gull, the European shag, and the common guillemot".

The protection regime of the new Natural Park was established in 1982, protecting all-natural values, as these were considered the geological, botanical, faunal, and landscape values, as well as archaeological and historical remains. To preserve all these, every user should be properly authorized by ICONA, establishing some expressly prohibited activities such as the access of visitors through unauthorized places or in a greater number than authorized by ICONA, the free camping, the garbage disposal, or the bonfires, among many others. According to this regulation, the Managing Board of the National Park established and approved in the same 1982 year a limit of 3000 persons per day in Cíes islands. Regarding urban uses, these did not appear expressly forbidden, but a procedure was established to eliminate the clandestine invasions, occupations, exploitation, and installations, as well as the mandatory coordination with the urban policy, including the elaboration of a Special Plan for Protection of the Natural Park. Even this plan was never approved, the declaration of the Natural Park would serve to paralyze the irregular construction activity in the archipelago, accompanied by dismantling and demolition of illegal constructions [20].

The transfer of the competencies in nature conservation to Galician regional government (Xunta de Galicia) were initially established Royal Decree 167/1981, which were finally consolidated by Royal Decrees 1706/1982 and 1234/1983, a new regulation was established in the Natural Park in 1983, in order to regulate the access of visitors to the islands. Joining to the 3000 persons per day limit, the visits to the Natural Park started to be prohibited when, through collective, public, or private boats of transport, a number greater than 10 people disembarked, or when they were disembarked by a place not expressly authorized by Xunta de Galicia. The visits of less than 10 people should be provided by the appropriate authorities of the National Park staff.

Regarding the forest plantations, the declaration of the Natural Park did not contribute to their environmental suitability. Although the new afforestation with exotic species would be partially replaced by native species plantations [34], ICONA still kept planting some areas with non-native species (*Quercus rubra*, *Fraxinus ornus*)

between 1979 and 1994, or they even made mixed plantations (with native and nonnative species). The basis of these actions does not differ much from the plantations made by PFE during the mid-20th century, as they lacked a prior assessment and they were carried out without a proper species selection criterion.

So, as a consequence of the Natural Park declaration, the wooden area in the islands continued to be increased, as a result of the forest plantations, but also it could be ascertained the invasive potential of some of the introduced species (*Eucalyptus globulus*, *Acacia dealbata*, *Acacia melanoxylon*), as they formed new several stands surrounding the previously planted plots, or even they formed new ones away from them. The resultant forest formations from all these plantations and the subsequent stands formed by invasive alien trees were represented in the vegetation maps at the end of the 20th century [35, 36], so high natural value habitats (coastal heaths, fixed dunes, humid slacks) were lost or negatively affected in these areas, although to a lesser extent than during the PFE period.

On the opposite, the definitive abandonment of the islands by the irregular residents and the elimination of their illegal constructions, allowed in these areas to increase the fixed dunes and coastal heaths in the archipelago, so natural values of the islands could partially recover. But as a result of the previous continued presence of these people, as well as by the continuation of transit of external visitors to the islands (even their presence was controlled by the Natural Park staff), the colonization of herbaceous invasive alien species was identified [34]. Perhaps the most worrying case is *Arcthoteca calendula*, although there are other species that also occupy significant areas, like *Zantedeschia aethiopica*, *Cortaderia selloana*, *Tritonia x crocosmiiflora*, *Carpobrotus edulis*, *Vinca difformis*, *Yucca gloriosa*, *Arundo donax*, *Tropaeolum majus*, etc.

In any case, all the efforts made in Cíes were evident and also favorable for the seabird colonies that were the main reason for the Natural Park declaration, so all those reached benefits allowed Cíes to be designated as a Special Protection Area for Birds (SPA) under Directive 79/409/EEC, as SPA "Illas Cíes" (ES0000001).

Although the other archipelagos (Ons, Sálvora, Cortegada) were not foreseen to be designated as natural protected areas in short term after Cíes Natural Park declaration, they were suffering some kind of similar conservation problems, so specific regulations were necessary to be approved, but outside the legal framework for natural protected areas.

The Ons situation during the 1980s and 1990s was very similar to Cíes. The new afforestation made from 1984 used native and exotic species [34], some of them with invasive potential, and mostly over high natural and seminatural value habitats (coastal heathland, hay meadows). The forest plantations were accompanied by a high density of new paths and roads, causing a high fragmentation of natural habitats, reducing their conservation status, and decreasing their permeability for the migration and genetic exchange of wild species. The basis of these actions was very similar to those made by PFE during the mid-twentieth century, as they lacked a prior assessment and they were carried out without a proper species selection criterion.

The unregulated access of visitors to Ons, especially during the summer, was motivating uncontrolled camping and shaft establishment in unsuitable locations and causing ecological, landscape, and social damages, so conservation measures were necessary. As Ons island territories were completely owned and managed by Xunta de Galicia, this regional public administration established in 1985 a first regulation for the access of visitors to the islands, so new permanent and nonpermanent constructions were forbidden, only allowing to camp in the area enabled for this purpose, and including the prohibition of bonfires. This first regulation was later updated in 1994, in order to prevent new impacts over high fragility

#### *Galician Atlantic Islands National Park: Challenges for the Conservation and Management… DOI: http://dx.doi.org/10.5772/intechopen.101844*

insular areas, establishing a limit of 80 people staying overnight in the campsite. However, new studies of insular carrying capacity were being drafted at that time, so when they were available, a new regulation was approved in 1995, in order to update the applicable rules to visitors and adapt the management, considering the improvement of the camping area, as it was prepared to receive 200 people. But the demand for new visits to the islands continued to be increasing, so the campsite was enlarged again, and 4 years later the limit raised up to 400 people in 1999, including the prohibition of circulation for motor vehicles.

As a result of all these regulations, Ons islands were allowed to be designated as a Special Protection Area for Birds (SPA) under Directive 79/409/EEC, as SPA "Illa de Ons" (ES0000254), because of the importance of the seabird colonies that were present in the insular territories.

Sálvora island did not suffer any significant change during the 1980s and 1990s, because it had been depopulated earlier than Cíes and Ons, it still was private property, and it was not so interesting for touristic purposes as this island is located in the outer part of Ulla river estuary, surrounded by very rough sea and many rocky reefs, making very difficult the approaching for boats. In fact, Sálvora has a long history of shipwrecks, which has led it to be described as a "boat cemetery" [37].

In the opposite, Cortegada island is located in the inner part of Ulla river estuary, surrounded by very calm waters and sandy flats, so the touristic interest was very high during the 1980s and the 1990s. It was privately owned by a real estate company [38, 39] whose main goal was the urbanization of the island, including hotels, chalets, casino, sporting marina, etc. This even motivated that a proper plan was drafted and approved by Vilagarcía de Arousa council, in order to adapt the municipality planning to allow Cortegada urbanization. But the lack of funding, coupled with the discovery of archaeological remains on the island, delayed this initiative, which was increasingly finding opposition from local environmental groups [40]. The natural and archaeological values, as well as the awareness rising from the society, led Xunta de Galicia in 1991 to establish a preventive protection regime for Cortegada island (through Decree 193/1991), according to the then current Law 4/1989 (that had substituted Law 15/1975), especially regarding the probable urban uses that were being planned at that time and that could potentially constitute a disturbance factor. This meant that any authorization or activity license to be developed in the archipelago that could transform its natural reality should be submitted to a mandatory and binding report from the regional public body responsible for urban and land use planning. This protection regime would be reinforced by the Complementary and Subsidiary Urban Norms of Pontevedra province, which in the same 1991 year would finally include the whole archipelago like "Natural Area", which meant that it was excluded from any possible urbanistic development.

At the end of 1990s, Cíes Natural Park was 10 years working, the rest of the islands had specific regulations to guarantee their conservation, and the efforts were starting to be successful at European level, with two SPAs in Cíes and Ons. In this scenario, it was necessary to expand the protection scope from Cíes to other Galician Atlantic islands in order to harmonize their economic activities and environment conservation, so a first joint management plan was drafted and approved (Decree 274/1999) for Cíes, Ons and Sálvora islands. The singularity and faunal richness of all these islands, as well as their variety of plant communities, high-value landscape, and geomorphology, justified the general interest of their conservation and met the criteria to become a National Park. Subsequently, it was assessed the opportunity and need to also integrate Cortegada islands, as they harbored similar natural, cultural and ethnographic values, so its corresponding management plan was approved 3 years after (Decree 88/2002). In accordance with the unique and fragile ecosystems and landscapes that deserve special protection in

the four archipelagos, both management plans designed a zonation for them. But it was established that this was considered as an indicative or preliminary zonation to serve as guidance until the moment it should be definitely established in their corresponding Master Plan for Use and Management (mandatory Plan according to the legal framework on protected areas).

So, all the necessary steps had been made, and the Maritime-Terrestrial Galician Atlantic Islands National Park was finally approved by Spanish Law 15/2002, first and only Galician National Park. The situation was also favorable to new natural protected areas initiatives, because the approval of the Directive 92/43/EEC had started, in parallel to the National Park declaration, the procedure for the designation of Galician Natura 2000 Network in 1999 with the first drafts, continued with the designation of the definitive Sites of Community Importance (SCI) in 2004, and the definitive transformation to Special Areas of Conservation (SAC) in 2014 through regional Decree 37/2014 approval. At the end of this process, these islands were included into three different SACs: Cíes was included in SAC "Illas Cïes" (ES0000001), Ons was included in "Complexo Ons-O Grove" (ES1140004), and Sálvora was included in SAC "Complexo húmido de Corrubedo" (ES1110006).

### **5. Actual challenges and strategies for biodiversity conservation**

Five months after the declaration of PNG, an ecological catastrophe occurred in the archipelagos, as they received the impact of the oil spill from the Prestige oil tanker, which sank 130 miles off the Galician coast. Sálvora and Ons were the most exposed islands, although Cíes also received a significant amount of oil. This discharge caused negative effects on marine and terrestrial ecosystems, including their habitats and species [41–46]. The clean-up work to remove the fuel from the coasts of Galicia lasted for 20 months. However, the importance of the islands of PNG in the coastal dynamics was confirmed during this great tragedy, since these archipelagos acted as a natural barrier against fuel, preventing a large part of it from reaching the neighboring coasts, especially the estuaries of Vigo, Pontevedra and Arousa, one of the most productive marine territories in the Atlantic Ocean.

In any case, the PNG declaration would entail a change in the management criteria of the terrestrial ecosystems of the archipelagos, beginning to carry out works and actions aimed at improving the conservation status of natural ecosystems, by reducing their impact factors fundamentally.

In Cíes islands, small experiments were beginning to be carried out on the elimination of non-native wooded formations planted by PFE and ICONA. The elimination of these formations responded to biodiversity conservation criteria since the occupation of the territory by forest plantations of non-native species caused a decrease of conservation status for natural habitats, as well as a break in the connectivity of ecosystems and therefore a reduction of their permeability for the present species. The elimination of exotic tree plantations also met safety criteria: sometimes, the size achieved by planted trees for more than 60 years caused these stands to reach a state of senescence, with high sizes that pose a risk of falling trees that could cause damage to natural components, people or real estate. Moreover, the presence of herbaceous invasive alien species still continued after the PNG declaration [47], so several initiatives for their removal started. Besides the herbaceous invasive alien species (*C. edulis*, *Arcthoteca calendula*, *Z. aethiopica*, *C. selloana*, *Tritonia x crocosmiiflora*, etc.), they started elimination of *E. globulus* and *A. melanoxylon* that previously invaded and encroached natural habitats. Nowadays, the invasive alien species conservation problem is one of the main concerns in NW Spain [48].

#### *Galician Atlantic Islands National Park: Challenges for the Conservation and Management… DOI: http://dx.doi.org/10.5772/intechopen.101844*

The elimination of forest plantations and invasive alien species formations was complemented by several actions for the recovery of fixed dunes. In Cíes, at various points of the islands, small formations of *E. globulus* and *A. melanoxylon* were eliminated on coastal scrub and dune habitats, and in parallel a series of visitor access control devices were installed for several years, preventing the transit of people in the dune system of Rodas beach. In Ons, a few forest plantations were carried out with native species, with a purpose to restore degraded areas, and dune regeneration actions also started on the beaches of Melide and Canexol, consisting in the elimination of tree and herbaceous invasive species (*E. globulus*, *A. melanoxylon*, *C. edulis*) and followed by the establishment of exclusion zones from people transit, to favor the regeneration of dune habitats. In Sálvora, the prohibition of transit through dune systems since PNG declaration led to the recovery of the degree of coverage of its characteristic herbaceous formations. In Cortegada, small areas of *Pinus* and *Eucalyptus* formations started to be removed, since the degree of senescence of these formations advised their elimination due to the high risk and danger to the surrounding habitats, as well as to the visitors of PNG.

All these measures allowed the recovery of habitats degraded by uncontrolled public use prior to the declaration of PNG, which caused sand erosion and area loss of the different types of natural habitats. The implementation of these measures made it possible to stop the area loss, and even achieve an increase in the occupied area by the dunes. An increase in the degree of coverage of the characteristic species of dune habitats was also achieved, as well as a recovery of their natural structure, which results in an improvement of the functionality of the dune ecosystem, and ultimately in an improvement of its future prospects.

The success of these initiatives would result in the recognition of these archipelagos as a new protected area under the European legal framework, which would join the SACs and SPAs that had already been previously designated by the regional government in Cíes, Ons, and Sálvora. In this way, the Spanish Government declared in 2014 a series of new SPAs in Spanish marine waters (Order AAA/1260/2014), including in one of them the maritime waters under Spanish sovereignty or jurisdiction that are surrounding these same three archipelagos (Cíes, Ons and Sálvora): SPA "Espacio Marino de las Rías Baixas de Galicia" (ES0000499).

Futhermore, considering the high importance of the marine biodiversity of PNG, this received two additional protection categories by international instruments. The first one was conferred in 2008, as it was integrated in OSPAR network, which is focused on the protection and conservation of marine ecosystems and diversity of North-East Atlantic, becoming the first Spanish protected area under OSPAR Convention. The second one is very recent, as in May 2021 PNG has definitely been included in the List of wetlands of international importance, as defined by the Ramsar Convention. This declaration implies its automatic consideration as "Protected Wetland", a regional category of protected area that is specifically designed for Galician wetlands that fulfill a function of international importance for natural resources conservation and especially as a habitat for waterfowl.

Paradoxically, the improvement of the conservation status of island ecosystems, and the promotion of new protected areas at a European and international level, would increase the demand for visits to the PNG archipelagos, in order to know and enjoy their landscape, their coasts, and their beaches. Every summer more and more people would visit the island territories, both in organized groups and on a discretionary basis, reaching the islands in collective or individual transport boats. The archipelagos that receive the highest number of visits are those with the largest continental area (see **Table 3**): Cíes often exceeds 300,000 annual visitors, Ons easily exceeds 140,000 visitors a year, Sálvora can reach more than 20,000 visits/year, and Cortegada often exceeds 10,000 visitors in the busiest years. In total, PNG is easily over 400,000 visits/year, touching 490,000 visitors during the peak years.


#### **Table 3.**

*Visitors per year in PNG archipelagos during 2017–2021 period (until September 15, 2021).*

In comparison with the Spanish Network of National Parks, PNG is among the ones with the lowest number of visitors per year, especially compared to some of the large mountain National Parks (**Table 4**), such as Guadarrama (33,960 ha) or Picos de Europa (67,128 ha), which can receive up to 2–3 million visitors a year. However, taking into account the territorial dimensions of PNG, with barely 1200 ha of land area, it receives a significant annual number of visitors, not negligible, similar or even higher than that of other large terrestrial National Parks, such as Aigüestortes (14,119 ha), Doñana (54,252 ha), or Monfragüe (18,396 ha).

Comparing the island National Parks (**Table 5**), the number of visits is directly proportional to those that occupy a greater land area. Such is the case of the Canarian National Parks such as Garajonay (3986 ha), Taburiente (4387 ha), Teide (18,990 ha), and Timanfaya (5107 ha), which range from more than 500,000 visitors a year in Taburiente, to more than 4 million annual visitors in Teide. The smallest insular National Parks, PNG, and Cabrera, both with a land area of just over 1000 ha, reach more than 400,000 visits per year in PNG, and just over 120,000 visits per year in Cabrera. Not inconsiderable figures, especially in the case of the Galician islands, taking into account that both are the only National Parks that have the consideration of "Maritime-Terrestrial" within the Spanish Network of National Parks, since their land area is a minority and they are mostly occupied by marine waters (7285 ha in the Galician islands representing 86% of the National Park, and 89,478 ha in Cabrera representing 99% of the National Park), making them difficult for visitors to arrive from the nearest coasts because the access is only possible by boat as there are no airports within these island territories.

The gradual increase of visitors to PNG (**Table 3**), given the condition of a National Park, motivated the preparation of a study of the carrying capacity of these archipelagos [49]. The concept of carrying capacity is a term widely used in the study of ecology, tourism, or sustainable use of resources [50–53], trying to approximate the maximum number of visitors that can use an area without significant alterations to the conservation status of the vulnerable elements or to the quality of the visitor experience. Traditional management approaches based on the strict application of the carrying capacity principle are suboptimal, so an adaptive management framework has been demanded, but it has been scarcely explored [54].

The results of the study of the carrying capacity [49], after taking into account the physical, psychological, ecological-environmental, global, and seasonal carrying capacity, allow establishing the maximum thresholds of visitors per day


*Galician Atlantic Islands National Park: Challenges for the Conservation and Management… DOI: http://dx.doi.org/10.5772/intechopen.101844*

> **Table 4.**

*Number of visitors per year in the Spanish Network of National Parks during the 2013–2019 period.*


#### **Table 5.**

*Number of visitors per year in the insular National Parks during the 2003–2019 period.*

(**Table 6**). This study was used as a scientific basis for the thresholds that would be established by the Master Plan of Use and Management (MPUM) of PNG, approved by Decree 177/2018, constituting the first protected area in Galicia to implement a study of these characteristics within its regulatory scope. The overall objective of this plan was the maintenance or, where appropriate, the reestablishment, in a favorable conservation status, of natural habitats and flora and fauna species of interest for conservation, taking into account economic, social, and cultural requirements, as well as regional and local particularities. So, MPUM included the provisions of the PNG Declaration Law (Law 15/2002) and of its initial planning instruments (Decree 274/1999, Decree 88/2002), as well as those established by Law 30/2014 on National Parks and by the Master Plan of the National Parks Spanish Network (Royal Decree 389/2016). Obviously, MPUM incorporated the guiding principles of European (Directives 92/43/EEC and 2009/147/EC), Spanish (Law 42/2007), and regional (Law 9/2001, currently replaced by Law 5/2019; Decree 37/2014) regulations of natural heritage, biodiversity, and protected areas.

In addition to the establishment of a carrying capacity limit for PNG archipelagos based on scientific-technical criteria, the MPUM (Decree 177/2018) defined definitive zoning, taking as orientation the preliminary zonation of the initial management plans (Decree 274/1999, Decree 88/2002), and following the criteria established in the Master Plan of the National Parks Spanish Network (Royal Decree *Galician Atlantic Islands National Park: Challenges for the Conservation and Management… DOI: http://dx.doi.org/10.5772/intechopen.101844*


*[PS]: Peak Season; [LS]: Low Season; A: límite de acceso diario en las navieras autorizadas para la realización de transporte colectivo; B: límite de acceso diario en grupos organizados y autorizados; C: límite de acceso diario por transporte marítimo (A + B); D: límite de personas en el camping; E: límite de fondeos diarios. Temporada baja; F: límite de acceso diario en grupos organizados y autorizados.*

#### **Table 6.**

*Maximum thresholds of visitors per day in PNG archipelagos, according to carrying capacity study [49].*

389/2016) for the zoning of maritime-terrestrial national parks. These criteria determine that vertical dimension has to be taken into account to adapt the delimitation of the marine zonation to the different depths and ecosystems, considering the water column, the seabed, and the isobaths. This aspect was incorporated into the zoning of Decree 177/2018, in which various marine zones of moderate use are contemplated on the surface of marine waters, while the seabed is included in another category of zoning (reserve marine zone, restricted-use marine zone). So, PNG has become the first Spanish National Park that has implemented this threedimensional methodology in its zoning scope and therefore has integrated it into its measure regime for management and conservation of natural heritage and biodiversity, when it comes to establish certain limitations of use for the different zoning categories that are defined in MPUM. In addition, taking into account the Natura 2000 consideration of PNG archipelagos, the zonation of the MPUM also kept a direct correspondence with the zoning units of the Master Plan of the Galician Natura 2000 Network (Decree 37/2014), in accordance with Law 42/2007, which provides that the Spanish categories of protected areas must be assigned to those internationally recognized, for the purposes of homologation and compliance with international commitments.

At present, after the initial conservation actions that followed the declaration of the National Park, and the regulation of visitor access according to the load capacity established with scientific-technical criteria, new challenges are being posed in the Atlantic islands of Galicia. In September 2021 has started a new LIFE project entitled "Integrated strategy for sustainable management of insular habitats in Natura 2000 islands of the Atlantic Ocean", whose acronym is LIFE INSULAR (LIFE20 NAT/ES/001007). It's a project that targets a favorable conservation status of fixed grey-dunes habitat (2130\*) and its contact habitat (4030) in Atlantic Ocean islands, spread across Atlantic and Macaronesian biogeographical regions. The project has a transnational scope, so eight Spanish and Irish Natura 2000 SACs have been selected to develop conservation actions, addressing common conservation problems and threats to increase the area and improve the structure and future prospects of targeted insular habitats in five different islands from both Member states. Three of them will be islands from PNG: Cíes, Ons, and Sálvora. Best practices of proven effectiveness will be applied, from September 2021 to December 2026, on targeted insular habitats to address common conservation problems and threats from a transnational approach. The covered area by the targeted habitats will be increased by elimination of old senescent forest plantations established by PFE and ICONA,

cultivation of characteristic plant species of insular habitats, and their restoration. Their structure and function will be improved through the control of competition against plant invasive alien species, as well as their future prospects through the improvement of habitat knowledge and protection measures against anthropogenic pressures. The project will be complemented by a transnational strategy to inform and raising public awareness to the general public about the relevance, natural values, and ecosystem services provided by insular ecosystems, as well as transferring the measures developed in the project for their replicability at the EU level through specific replication and networking strategies. LIFE INSULAR is expected to have a great demonstrative character, allowing high replicability and transferability to other European island territories, or even worldwide, so it is considered that the selected insular territories will be representative from two biogeographical regions where European Natura 2000 islands in the Atlantic Ocean are located.
