Archipiélago de Revillagigedo

 © IUCN / German Soler
Country
Mexico
Inscribed in
2016
Criteria
(vii)
(ix)
(x)
The conservation outlook for this site has been assessed as "good with some concerns" in the latest assessment cycle. Explore the Conservation Outlook Assessment for the site below. You have the option to access the summary, or the detailed assessment.

Located in the eastern Pacific Ocean, this archipelago is made up of four remote islands and their surrounding waters: San Benedicto, Socorro, Roca Partida and Clarión. This archipelago is part of a submerged mountain range, with the four islands representing the peaks of volcanoes emerging above sea level. The islands provide critical habitat for a range of wildlife and are of particular importance for seabirds. The surrounding waters have a remarkable abundance of large pelagic species, such as manta rays, whales, dolphins and sharks. © UNESCO

 © IUCN / German Soler
© IUCN / German Soler

Summary

2020 Conservation Outlook

Finalised on
02 Dec 2020
Good with some concerns
The geographical isolation of the site and its effective management make its Conservation Outlook overall positive, even if the situation could change if some of the major threats to its values (in particular, invasive species but also illegal fishing within the site or fishing in the surrounding waters) increase or are not managed properly. Despite all these current or potentially serious threats, management is in place to mitigate threats whenever possible, with the hope that the invasive species problems will be resolved in the near future. Clear management procedures are in place through a comprehensive Management Plan, and implementation is undertaken through a number of government departments as well as other institutions and NGOs. The isolation of the site is probably the most difficult challenge in ensuring comprehensive protection, but its isolation is also the main factor that has contributed to its relatively good conservation status today.

Current state and trend of VALUES

Good
Trend
Stable
The current state and trend of World Heritage values is good and stable. The outstanding marine biodiversity remains in good condition with recent assessments indicating a high level of conservation for the hundreds of marine species conserved in the site (Aburto-Oropeza et al, 2017; Becerril-García et al, 2020; Fourriere et al, 2016). Terrestrial ecosystem-related values actually improved with the eradication of sheep and pigs from the islands prior to inscription. Cats are also being controlled, and after complete eradication, trends in terrestrial biodiversity should improve. The population of rabbits, however, is still out of control and needs to be addressed as soon as possible. Regarding marine values, recent assessments indicate that conservation level is high and effective despite some threats (Aburto-Oropeza et al, 2017).

Overall THREATS

High Threat
The greatest current threat is the existence of feral cats on Socorro and rabbits on Clarión. Cats on Socorro have now been reduced to very low numbers and are being controlled and monitored with the aim of total eradication. A project to eliminate rabbits on Clarion failed, but other campaigns are being planned to diminish their populations. Other threats include fishing inside and outside the property, diving tourism pressure, and natural events including frequent hurricanes and occasional volcanic eruptions. Potential threats are introduction of invasive species such as rats or increased issues with invasive species such as locusts, and climate change could affect the property in unexpected ways. Despite all these current or potentially serious threats, management is in place to deal with these threats, with the hope that the invasive species problems will be resolved in the near future.

Overall PROTECTION and MANAGEMENT

Mostly Effective
Overall, protection and management of the World Heritage site is effective, particular with regards to its terrestrial component. However, some concerns exist with regards to the capacity to effectively manage marine areas. Clear management procedures are in place through a comprehensive Management Plan (CONANP, 2018), and implementation is undertaken through a number of government departments as well as other institutions and NGOs. The isolation of the site is probably the most difficult challenge in ensuring comprehensive protection, but its isolation is also the main factor that has contributed to its relatively good conservation status today.

Full assessment

Click the + and - signs to expand or collapse full accounts of information under each topic. You can also view the entire list of information by clicking Expand all on the top left.

Finalised on
02 Dec 2020

Description of values

Exceptional landscape and seascape

Criterion
(vii)
The landscape of the four islands comprising the Archipiélago de Revillagigedo exhibit impressive active volcanos, arches, cliffs, and isolated rock outcrops emerging from the middle of the ocean (World Heritage Committee, 2016). The crystal clear waters of the property create exceptional scenic vistas with large aggregations of fish gathering around the steep walls and seamounts, as well as large pelagic marine species including Giant Manta Rays, whales, dolphins and sharks (World Heritage Committee, 2016).

Awe-inspiring underwater experience

Criterion
(vii)
The property encompasses an underwater seascape with abyssal plains at depths close to 4,000 meters and sheer drops in crystal clear water, all contributing to an awe-inspiring underwater experience. A large population of up to 2,000 Humpback Whales visits the islands. The songs of these majestic cetaceans can be heard during the winter months and while diving, add another sensory dimension to the marine seascape. One of the most remarkable aspects of the property is the concentration the Giant Manta Rays which aggregate around the islands and interact with divers in a special way that is rarely found anywhere in the world (World Heritage Committee, 2016).

Unique set of biological and ecological processes

Criterion
(ix)
The property lies in the northern part of the Tropical East Pacific Province, a transitional zone influenced mainly by the California current but mixed with the warm waters from the North Equatorial Current. This location results in the convergence of a multitude of fauna and flora, and creates a unique set of biological and ecological processes (World Heritage Committee, 2016).

On-going terrestrial evolution

Criterion
(ix)
The isolation and relatively pristine state of these islands has supported evolutionary processes which result in a high degree of endemicity. Two species of lizards, 2 endemic snakes, 4 endemic birds, at least 33 endemic plant species and unknown numbers of invertebrates are endemic to the islands. In addition, 11 endemic subspecies of birds have evolved, indicating the potential for future evolution on these remote and well protected islands (World Heritage Committee, 2016).

Outstanding terrestrial biodiversity

Criterion
(x)
The Archipiélago de Revillagigedo is home to the endemic Socorro Dove (currently Extinct in the Wild), Socorro Mockingbird, Socorro Wren, Clarion Wren (as well as 11 endemic bird subspecies), 2 lizards, 2 snakes and numerous endemic plants and invertebrates (World Heritage Committee, 2016).

Outstanding marine biodiversity

Criterion
(x)
The geographic isolation of the Archipiélago de Revillagigedo, shaped by the prevailing oceanographic conditions, results in high marine productivity, rich biodiversity and exceptional levels of endemism. At least 10 reef fish species have been identified as endemic or near-endemic including the spectacular Clarión Angelfish, which can be observed in ‘cleaning stations’ feeding on the ectoparasites of the Giant Manta Rays and dolphins. These rays, some of them unusually completely black, aggregate in some of the largest numbers known worldwide. The property is a haven for a rich diversity of shark species with up to 20 having been recorded, as well as for the seasonally large population of up to 2,000 Humpback Whales (World Heritage Committee, 2016).

Significant importance for breeding seabirds

Criterion
(x)
The islands are the only breeding site for the Townsend’s Shearwater, one of the rarest seabirds in the world. They are also of significant importance to other breeding seabirds, notably Masked, Blue-footed, Red-footed and Brown Boobies; Red-billed Tropicbirds; Magnificent Frigatebirds and many other species which can be seen soaring around the rocky outcrops where they nest and fish in the sea (World Heritage Committee, 2016).
Green Turtle breeding site
Green Turtles nest on Clarion at Bahia Azufre, the only place where they can lay their eggs. As many as 500 green turtle nests were estimated over a 2-week period, making the site one of the three main breeding grounds for the Green Turtle population in the Pacific Ocean (State Party of Mexico, 2015). According to preliminary data, the Green Turtle population may also be nesting in Socorro.

Assessment information

High Threat
The greatest current threat is the existence of feral cats on Socorro and rabbits on Clarion, and there are efforts underway to eliminate both of these pests. Other threats include overfishing and illegal fishing inside and outside the property, diving tourism pressure, and natural events including frequent hurricanes and occasional volcanic eruptions. Despite potentially high threats, management is in place to deal with these threats whenever possible, with the hope that the invasive species problems will be resolved in the near future.
Invasive Non-Native/ Alien Species
(Cats and to a lesser extent mice on Socorro; rabbits on Clarion.)
High Threat
Inside site
, Throughout(>50%)
Cats are the major threat to the breeding Townsend's Shearwater and other endemic and non-endemic birdlife on Socorro. Active measures are still being undertaken to control them with a view to eradication (Ortiz-Alcaraz et al, 2019). The number of feral cats is currently low (Ortiz-Alcaraz et al, 2019). The diminishing numbers of cats and the total eradication of sheep have significantly helped in the restoration of vegetation in Socorro (Ortiz-Alcaraz et al, 2019; Ruiz-Guerra et al, 2019). With a lower predation from cats on native birds that feed on caterpillars and insects, the native vegetation has increased (Ortiz-Alcaraz et al, 2019; Ruiz-Guerra et al, 2019). Rats have also been shown to be detrimental to seabird colonies, but fortunately these rodents have not been introduced to the islands. The rabbits on Clarion are harmful to both native flora and fauna. They also cause erosion, which is detrimental to terrestrial biodiversity as well as the surrounding marine life (State Party of Mexico, 2015; IUCN, 2016). Rabbits are still present in Clarion with plans to eradicate them in the near future (IUCN Consultation, 2020). 
Fishing / Harvesting Aquatic Resources
(Commercial and sport fishing)
High Threat
Inside site
, Throughout(>50%)
Outside site
Commercial industrial fishing (yellowfin tuna, several shark species), fishing bycatch and sportfishing threaten marine values, although it is noted that ecological impacts have not reached serious levels since shark aggregations still occur and in greater numbers than in any other island or archipelago in the region. However, the abundance of pelagic sharks have had a downward trend from the 1970s to 2007 (Basque 2007) and this trend may have continued to recent years. It is true that the current National Park has helped in the increased sightings of sharks and tuna, but the recovery to historical abundances observed in the 1970s are yet to be seen. Bycatch is also another threat that could affect seabirds and giant mantas, as well as isolated incidents with entangling of dolphins, thresher sharks and other pelagic fauna. Since the expansion of the no-take area to over 14 M hectares, sport fishing has been banned (State Party of Mexico, 2018). However,  the targeted species are most likely to be also threatened by illegal fishing and poaching activities (Aburto-Oropeza et al., 2017). The authorities report a high level of compliance by Mexican fishers, but in 2019 three boats were prosecuted, including a sport fishing boat from the U.S. (Blue Parks, 2002). Nevertheless, as several key species are migratory, a key threat relates to poor fisheries management and enforcement outside the protected area, in Mexican waters, in other jurisdictions and in the high seas.
Volcanic activity
(Volcanic eruption)
Low Threat
Inside site
, Widespread(15-50%)
Socorro has more than 20 active volcanoes and eruptions during the 17th and 18th centuries have had negative effects in the island's ecosystem. The main volcano on Socorro, Volcan Evermann, is located in the middle of the island. In January 1993 it recorded a high increase in volcanic activity which has caused important changes on the ecosystem, mostly in the surrounding waters, as an increase in temperature and decrease in pH. The consequences for the biota have been extirpation of some algae and seagrass species and a displacement of marine fauna from that particular area. Also, on Isla San Benedicto, its main volcano, Barcena, was born in 1952 with a very violent eruption that caused the complete devastation of flora and fauna on the island and surrounding waters. Some species survived and others colonized or re-colonized the island, so to date this ecosystem is recovering (State Party of Mexico, 2015).
Ocean acidification, Temperature extremes, Storms/Flooding
(Hurricanes)
Low Threat
Inside site
, Extent of threat not known
Hurricanes are common and strong in the Archipiélago de Revillagigedo. They have a marked seasonality, usually between June and November. While the native fauna and flora should be adapted to hurricanes, climate change could increase the intensity of these events (State Party of Mexico, 2015).
Fire/ Fire Suppression
(Fire)
Low Threat
Inside site
, Scattered(5-15%)
Infrequent fires, either accidental or caused by tropical storms (lightning) or volcanic activity, have occurred on Socorro and Clarion. They are dispersed mainly through invasive forbs and grasses, thus the eradication of sheep on Socorro and the removal of rabbits on Clarión, which are necessary and considered as a priority action for the archipelago, will also diminish the fire risk (Sate Party of Mexico, 2015).
Other Activities
(Naval base)
Low Threat
Inside site
, Localised(<5%)
Two small naval bases are located on Socorro and Clarion. As long as biosecurity plans are enforced, these two bases should not pose a great threat to the property. There is an advance draft version of the Biosecurity plan for Revillagigedo, which should be finalize in the near future (IUCN Consultation, 2020). These bases are important, as the military help with the protection of the site (State Party of Mexico, 2015; IUCN, 2016; State Party of Mexico, 2018).
Tourism/ visitors/ recreation
(Diving)
Low Threat
Inside site
, Scattered(5-15%)
The main recreational activity in the property are live-aboard dive boats. Currently, the carrying capacity linked to the diving activity is at its limit in some of the dive sites (State Party of Mexico, 2015; State Party of Mexico, 2018; IUCN Consultation, 2020). While moorings have not been installed, anchoring is allowed only in specific sandy sites. The extent of anchoring damage is unknown. Reports of compliance with diving limits are contradictory. Officials report that dive limits have been established and the presence of park rangers in each vessel increase compliance (Blue Parks, 2020). Others report that diving limits are not enforced in certain areas for several reasons: 1) there are too many diving operators, and this activity was established before the park designation; this makes limiting the activity very difficult.  2) Certain weather conditions force dive boats to limit their activity to a few sites, and in those cases dive limits are exceeded (IUCN Consultation, 2020). However, whenever possible dive boats follow a rotation process in the dive sites limiting the number of divers per group to less than 8 people and less than 36 divers per hour per site (State Party of Mexico, 2018). 
High Threat
The greatest potential threat to the property would be the inadvertent introduction of rats to the islands, and biosecurity plans urgently require strengthening, especially as large naval ships occasionally dock on Socorro. Invasive locusts may also pose problems in the future. Climate change could pose greater threats though increased hurricanes or ocean acidification.
Problematic Native Species
(Invasive locusts)
Data Deficient
Inside site
, Extent of threat not known
The Centroamerican locust (Schistocerca piceifrons Orthoptera: Actididae) was apparently self-introduced. The species is sympatric with two other native species. At least from 1993 there have been reports of heavy defoliation on localized areas of Socorro. Considering the potential size of locust populations and the size of the island, they must be doing considerable damage to the native flora. Unfortunately, the extent of damage has never been thoroughly evaluated. It is also not clear how the locusts are affecting the native fauna. The endemic locust seems to be confined to higher elevations, perhaps because of competitive exclusion. It is also obvious from anecdotal evidence that the locust populations have been on the rise for the past few years (State Party of Mexico, 2015).
Invasive Non-Native/ Alien Species
(Potential introduction of rats)
High Threat
Inside site
, Widespread(15-50%)
Rats have not been introduced to the islands but given that at times large ships dock at the naval base, a biosecurity plan to ensure that rats are never introduced to the island is essential. A plan was under discussion during the time of the evaluation (IUCN, 2016) and a Insular Biosecurity Protocol of the Revillagigedo National Park is under review (State Party of Mexico, 2018).
Ocean acidification, Temperature extremes, Storms/Flooding
(Climate change)
Data Deficient
Inside site
, Throughout(>50%)
Climate change has the potential to affect the property by increasing the intensity of hurricanes, causing temperature extremes and acidification of the ocean (State Party of Mexico, 2015). Increased sea-surface temperatures (SSTs) associated with climate change/global warming have caused bleaching in scleractinian corals (the loss of obligate symbiotic zooxanthellae) on a global basis, resulting in mass mortality of corals and decimation of reefs (IUCN Consultation, 2020). This symbiotic relationship makes these corals an excellent bioindicator of climate change
The greatest current threat is the existence of feral cats on Socorro and rabbits on Clarión. Cats on Socorro have now been reduced to very low numbers and are being controlled and monitored with the aim of total eradication. A project to eliminate rabbits on Clarion failed, but other campaigns are being planned to diminish their populations. Other threats include fishing inside and outside the property, diving tourism pressure, and natural events including frequent hurricanes and occasional volcanic eruptions. Potential threats are introduction of invasive species such as rats or increased issues with invasive species such as locusts, and climate change could affect the property in unexpected ways. Despite all these current or potentially serious threats, management is in place to deal with these threats, with the hope that the invasive species problems will be resolved in the near future.
Management system
Highly Effective
The islands are managed as a natural protected area by the National Commission of Natural Protected Areas (CONANP) in close collaboration with other government institutions and various NGO and university partners. A comprehensive Management Plan for the property is in place (CONANP, 2018). While the islands form part of a serial property, they come under a single management system (CONANP, 2007; State Party of Mexico, 2015).
Effectiveness of management system
Mostly Effective
Management systems, including a broad stakeholder advisory board that meets biannually, are undertaken under the provisions of Mexican law and the Management Plan (CONANP, 2007; State Party of Mexico, 2015). Prior to inscription, sheep and pigs were eradicated from the Property, and cats from Socorro are well on the way, attesting to good management effectiveness; however, the rabbit problem on Clarión still needs to be resolved (Aguirre et al., 2011).
Boundaries
Mostly Effective
President Enrique Peña Nieto, during the event of receipt of the World Heritage List inscription certificate and unveiling of the commemorative plaque on Isla Socorro in November 2016, instructed the Mexican government institutions "to look for the coordination mechanism to increase an area of greater protection of the Archipiélago de Revillagigedo that assures its due care". The idea was to not only comply with the recommendations but to go further and ensure the protection of the Property (State Party of Mexico, 2018). Given this, the CONANP carried the feasibility studies and justification to  declare the Natural Protected Area under the category of National Park on November 27th 2017. The current Revillagigedo Archipelago National Park has a total area of 14,808,780 hectares of which 14,793,261 correspond to the marine portion and 15,518 to the insular terrestrial portion integrated by Clarion Island, San Benedicto Island, Socorro Island and Roca Partida Island (State Party of Mexico, 2018). It should be mentioned that National Park is one of the most restrictive conservation categories in the Mexican national legislation. This new category does not allow any extractive activity, including fishing, which will contribute to the conservation of biodiversity and the ecosystems and ensure, in the long term, the protection of the Outstanding Universal Value and strengthen marine connectivity (State Party of Mexico, 2018). The increase of the area of protection of the old biosphere reserve to the current National Park was based on a study of the movements and connectivity of sharks and mantas in the archipelago (Ketchum et al. 2020). The connectivity between these islands is crucial for many elasmobranchs such as Giant Mantas, Silvertip, Tiger, Silky, Galapagos, and Scalloped Hammerhead Sharks, as they perform long foraging forays (State Party of Mexico, 2015; Ketchum et al. 2020).
Integration into regional and national planning systems
Mostly Effective
The World Heritage site is included in the "Estrategia Nacional para la Conservación y el Desarrollo Sustentable del Territorio Insular Mexicano" (Comité Asesor Nacional sobre el Territorio Insular Mexicano, 2012). It forms part of the Mexican Protected Areas network managed by CONANP (State Party of Mexico, 2015). As many species are migratory, protected area management needs to work conjointly with effective fisheries management in other Mexican waters and in the region. This means that a strong coordination is needed with other countries in the Eastern Tropical Pacific and other relevant regions, including with agencies working both on protected areas and fisheries management. An interest to work with the governments of Costa Rica, Panama, Colombia and Ecuador in the CMAR initiative is an important step in this direction. Mexico needs to participate actively in international treaties to expedite solutions to the issues surrounding high seas management and control to reduce the threats of open access fisheries on key migratory species.  
Relationships with local people
Highly Effective
The new designation of the Archipielago de Revillagigedo as a National Park is a category most suited, considering that there are no resident communities living on the islands (State Party of Mexico, 2018).
Legal framework
Highly Effective
The designation of the Archipielago de Revillagigedo as a National Park falls under the jurisdiction of the Mexican federal territory (State Party of Mexico, 2018).  The Property is protected under a range of legislation pertinent to different agency jurisdictions with the principal protective legislation being the General Law of Ecological Balance and the Protection of the Environment (LGEEPA). The islands are managed by the Natural Commission of Natural Protected Areas (CONANP) in close collaboration with a number of other government authorities, various NGO and university partners, tourist operators and other stakeholders who are part of, by law, an advisory committee that meets twice yearly (State Party of Mexico, 2015).
Law enforcement
Some Concern
While staffing of the World Heritage site by the management agency CONANP is modest, there is effective collaboration with the Mexican Navy who provide staffing and infrastructure support to patrol the islands and ensure the enforcement of regulations. Coordination with the fisheries authority also increases efficiency of surveillance and control activities. Currently, most of the diving liveaboards are accompanied by National Park personnel, increasing the institutional presence in the marine area (State Party of Mexico, 2018). However, the marine area is large and increased patrolling is needed to ensure enforcement of regulations  (State Party of Mexico, 2018; IUCN, 2016).  Automatic Identification Systems (AIS) are being used by the State Party of Mexico to monitor the maritime traffic and fishing inside and around the reserve (IUCN Consultation, 2020). Since the declaration of Revillagigedo as a National Park and its expansion to over 14 million hectares the number of boats inside the boundaries and/or near the islands has substantially decreased (IUCN Consultation, 2020). 
Implementation of Committee decisions and recommendations
Mostly Effective
The World Heritage Committee requested increasing legal protection and revising the Management Plan to extend the no-take zone to 12 nautical miles from the islands, strengthening invasive species eradication and biosecurity plans and managing potential increases in recreational diving as well as the deployment of mooring buoys, to be reported upon by December 2018 (World Heritage Committee, 2016). Regarding the expansion of the area, the State Party of Mexico under a federal decree declared the Revillagigedo Archipelago as a National Park in November 2017 with a total area of over 14 million hectares, expanding the no-take area not only to 12 nautical miles around the island but including all of the previous buffer zone as a no fishing or extraction zone (State Party of Mexico, 2018). This decision by the Mexican government surpassed all expectations and is a model to follow. In regard to the invasive species eradication, the Revillagigedo National Park Directorate signed in 2018 collaborative programs with two NGOs (Conservación de Islas and ECO), both for biological monitoring in the marine portion of the World Heritage site and for the control and eradication of invasive alien species in the insular territory. In this respect it is estimated that a small population of around 40 feral cats remain in the wild in Socorro Island. These cats are being monitored through trapping and with specialized dogs for control and eradication (State Party of Mexico, 2018). Regarding the invasive rabbits and black iguanas in Clarion, their numbers have been monitored and remain high in the case of the rabbits (between 30 and 40 thousand individuals) and unknown in the case of the black iguana.   Regarding biosecurity plans, there is an Insular Biosecurity Protocol of the Revillagigedo National Park (currently under review) that aims to guarantee the conservation of the Outstanding Universal Value of the Archipiélago de Revillagigedo Property. This Protocol will help to prevent the future introduction and invasive or alien species, and the control and eradication of those that are currently in the National Park (State Party of Mexico, 2018). In regard to the careful management of tourism, during the 2014-2015 and 2016-2018 periods, work meetings were held with advisory council and the authorized service providers, to review and update the carrying capacity of the autonomous diving sites within the area. This resulted in the Carrying Capacity Update for  autonomous Diving of the Revillagigedo National Park, 2018 (Reyes-Bonilla et al. 2015; State Party of Mexico, 2018). Based on this study, seven diving sites were recognised as being used on a regular basis by tourist operators. Some of these sites were estimated to be at the limit of their carrying capacity and therefore limits have been set, particularly in Roca Partida and El Boiler as the most sensitive sites in terms of carrying capacity (Reyes-Bonilla et al. 2015). In order to closely monitor the diving activity in the area, personnel of National Parks are on board on most of the diving trips to the Archipelago. This allows a close follow up of the diving operations and their possible impacts. Regarding the deployment of permanent mooring buoys, this have not been performed and it is important to achieve this goal. However, clear anchoring areas have been identified, which are mainly in the sandy areas around the dive sites (State Party of Mexico, 2018).   
Sustainable use
Mostly Effective
Since the designation by the Mexican Government of the Archipielago de Revillagigedos as a National Park, it is prohibited to undergo any extraction activity such as fishing. On the other hand tourism is the main sustainable use, and it is being closely monitored by the National Park personnel (State Party of Mexico, 2018). Impact of anchoring operations and possible breaches of diving limits in some sites need closer monitoring.
Sustainable finance
Mostly Effective
Two main funding sources, the federal government and the public-private fund Fondo para Areas Naturales Protegidas (FANP), cover most operational costs. Funding has increased, particularly from FANP, with an overall budget of 67,634 for 2020. Staff salaries are separate to annual budget, and there are currently 10 staff members, covered by FANP and UNDP (Blue Parks, 2020). Other funding comes from specific projects. Additionally, cooperation among agencies, in particular with the Navy, is important to provide the means to control the extensive waters of the World Heritage Site (State Party of Mexico, 2015; Blue Parks, 2020). Coordination with the fishing authority, CONAPESCA, further supports fishing monitoring actions, particularly through access to information from satellite monitored fishing boats; this is important to optimise control of potential illegal fishing (Blue Parks, 2020).
Staff capacity, training, and development
Mostly Effective
Ten permanent staff with a high level of competency and skills manage the reserve. Some are based in the mainland offices and others spend long periods in the island of Socorro or onboard the live-aboards (State Party of Mexico, 2018; IUCN Consultation, 2020).
Education and interpretation programs
Mostly Effective
At present there is no infrastructure dedicated to visitors on the islands, as the only visitation to the islands is by naval personnel and scientific researchers. Park rangers on board diving vessels help increase conservation awareness and capacity of dive operators (Blue Parks, 2020); these park rangers most likely interact closely with visitors and can increase marine literacy and awareness as part of an environmental education plan. Conservation education is undertaken in the neighbouring States of California Baja Sur and Colima (State Party of Mexico, 2015; State Party of Mexico, 2018).
Tourism and visitation management
Mostly Effective
At present the only visitation to the islands is by naval personnel and scientific researchers. The main tourism is through diving companies on live-aboard vessels, which are managed through the Management Plan (CONANP, 2007; State Party of Mexico, 2015).
Monitoring
Mostly Effective
Monitoring with clear indicators is undertaken within specific time-frames by CONANP and the NGO Grupo Ecológico y de Conservación de Islas (State Party of Mexico, 2015). Other NGO and universities also contribute to monitoring efforts.
Research
Mostly Effective
Research in collaboration with numerous institutions is undertaken in the Property (State Party of Mexico, 2015). NGOs (e.g. Pelagios Kakunjá, Conservacion de Islas, etc.) and Universities contribute significantly to an increased understanding of terrestrial and marine ecosystems.
Overall, protection and management of the World Heritage site is effective, particular with regards to its terrestrial component. However, some concerns exist with regards to the capacity to effectively manage marine areas. Clear management procedures are in place through a comprehensive Management Plan (CONANP, 2018), and implementation is undertaken through a number of government departments as well as other institutions and NGOs. The isolation of the site is probably the most difficult challenge in ensuring comprehensive protection, but its isolation is also the main factor that has contributed to its relatively good conservation status today.
Assessment of the effectiveness of protection and management in addressing threats outside the site
Some Concern
The greatest threat from outside the site is unsustainable fishing which could impact the OUV of the site. While the Mexican Government can manage fishing within its national waters, over-fishing in international waters could have an effect on the site.
Best practice examples
-A significant extension of the no-take area has improved management of fisheries impacts and presumably the conservation status of key marine species, migratory marine species and insular and oceanic habitats.

-Good coordination with a variety of stakeholders (particularly the Mexican Navy, the fisheries agency and NGOs) optimizes the use of financial and human resources, and increases effectiveness.

-The eradication program of sheep and cats seems to have been quite successful, and continuing these efforts should ensure that feral populations do not increase again. 
World Heritage values

Exceptional landscape and seascape

Good
Trend
Stable
The islands' landscape is imposing with majestic cliffs, beaches and volcanoes, some of them very active. The highest volcano in Socorro rises 1050 meters above sea level and is active with vents producing clouds from its boiling waters. The view of guano-covered Roca Partida, arising out of the middle of the ocean is spectacular (State Party of Mexico, 2015; IUCN, 2016). The shear drops into crystal clear water and rich and varied marine life provide a superlative underwater beauty (State Party of Mexico, 2015; IUCN, 2016). A total of 235 reef fish species have been recorded for the archipelago, making this site an exceptional seascape. 

Awe-inspiring underwater experience

Good
Trend
Stable
The site protects some of the richest marine ecosystems in the world with great aggregations of pelagic fauna such as rays, tunas, turtles, whales and sharks. The Giant Manta Rays which aggregate around the islands have a very special interaction with divers like nowhere else in the world. Seasonally, the calls of an important population of Humpback Whales provide an awe-inspiring underwater experience (State Party of Mexico, 2015; IUCN, 2016).

Unique set of biological and ecological processes

Good
Trend
Stable
The unique location of the site in a transitional zone influenced mainly by the California current which mixes with the warm waters from the North Equatorial Current, result in the convergence of a multitude of fauna and flora. The endemism of the terrestrial and marine fauna, as well as vast congregations of certain species is vivid proof of the important evolutionary process at play in these islands (State Party of Mexico, 2015; IUCN, 2016).

On-going terrestrial evolution

Good
Trend
Stable
Given the distance to the mainland, strong evolutionary pressure has been put on the speciation process with a high level of endemism of terestrial taxa (birds, reptiles, insects, plants) at the subspecific, specific and even generic level. Some unique evolutionary processes such as that recorded for the Clarion Burrowing Owl add to the unique processes occurring on the islands (State Party of Mexico, 2015; IUCN, 2016).

Outstanding terrestrial biodiversity

Low Concern
Trend
Stable
While islands in general have low terrestrial biodiversity, the high level of endemism in the Property's terrestrial flora and fauna make it outstanding. Although one of its flagship species, the Socorro Island Dove, is Extinct in the Wild, it is hoped that once cats are eradicated from the island a reintroduction of this species may take place (State Party of Mexico, 2015; IUCN, 2016). The population of rabbits, however, is still out of control and needs to be addressed as soon as possible (IUCN Consultation, 2020).

Outstanding marine biodiversity

Good
Trend
Stable
The quantity of a wide diversity of marine species, including cetaceans, sharks, rays and turtles, as well as rather exceptionally good number of endemic species make this an area of outstanding marine biodiversity (State Party of Mexico, 2015; IUCN, 2016). A total of 389 species of fish have been reported for the archipelago; 235 of these are reef fish that occur in the Eastern but also in the Central Pacific, and 13 species were identified as endemic to the archipelago (Fourriere et al, 2016). Recently it was reported the occurrence of 28 chondrichthyan species, including 19 sharks, seven batoids and two chimaeras in the Revillagigedo Archipelago (Becerril-García et al, 2020). Recent assessments indicate that conservation level is high and effective despite some threats (Aburto-Oropeza et al, 2017).

Significant importance for breeding seabirds

Good
Trend
Stable
While the number of seabird species within the Property is relatively low, 46 species have been recorded with 12 breeding, the most important of these being the Townsend's Shearwater, which only breeds on Socorro Island (State Party of Mexico, 2015; IUCN, 2016).
Assessment of the current state and trend of World Heritage values
Good
Trend
Stable
The current state and trend of World Heritage values is good and stable. The outstanding marine biodiversity remains in good condition with recent assessments indicating a high level of conservation for the hundreds of marine species conserved in the site (Aburto-Oropeza et al, 2017; Becerril-García et al, 2020; Fourriere et al, 2016). Terrestrial ecosystem-related values actually improved with the eradication of sheep and pigs from the islands prior to inscription. Cats are also being controlled, and after complete eradication, trends in terrestrial biodiversity should improve. The population of rabbits, however, is still out of control and needs to be addressed as soon as possible. Regarding marine values, recent assessments indicate that conservation level is high and effective despite some threats (Aburto-Oropeza et al, 2017).
Assessment of the current state and trend of other important biodiversity values
Good
Trend
Stable
It would appear that the current trend of the Green Turtle nesting population on Clarion is good and stable, but it should be noted that the IUCN evaluation mission of 2015 was not able to visit this part of the property due to logistical reasons.

Additional information

Outdoor recreation and tourism,
Natural beauty and scenery
The main benefit to tourists in the property is recreational diving, where people can admire the exceptional scenery and underwater events (State Party of Mexico, 2015; IUCN, 2016).
Factors negatively affecting provision of this benefit
Pollution
Impact level - Low
Trend - Continuing
Overexploitation
Impact level - Low
Trend - Continuing
Diving tourism is limited through the Management Plan thus pollution and disturbance is limited. Also a Carrying Capacity Update for Autonomous Diving in the Revillagigedo National Park was undertaken in 2015 and 2018 (Reyes-Bonilla et al. 2015; State Party of Mexico, 2018). A recommendation to install permanent diving buoys to avoid anchor damage has been made (World Heritage Committee, 2016), however up to date they have not been installed. It is critical that these buoys are installed to avoid anchor damage on the reef, corals and cleaning stations.
Importance for research
Revillagigedo has been called the "Galapagos of Mexico", and numerous studies on the ecology and evolution of its isolated flora and fauna as well as its marine life have been and continue to be undertaken (State Party of Mexico, 2015). The Archipiélago de Revillagigedo is a natural laboratory that provides a unique opportunity to study insular and oceanic marine species, where full assemblages of this fauna are still present. These islands are considered a climate change refugia, which should underpin most current and future studies on this incredible archipelago. During a submersible expedition (Steward et al., 2016) the first data on the giant manta and tiger sharks (Hoyos-Padilla et al, in prep) foraging at depth was recorded. Satellite tags deployed also recorded seasonal shifts in diving behavior, likely related to changes in the location and availability of prey. Understanding the foraging ecology of threatened species will aid in their conservation and management as feeding behavior often determines critical habitat use and spatial patterns that are important in preventing or mitigating human impacts (James et al, 2006).

 
Tourism-related income,
Provision of jobs
Diving operations in the World Heritage site contribute to the economy. A small number of jobs are created through Park management and diving operators (State Party of Mexico, 2015; CONANP, 2004). Visitors fees help finance the site.
Factors negatively affecting provision of this benefit
Pollution
Impact level - Low
Trend - Continuing
Overexploitation
Impact level - Low
Trend - Continuing
Diving will create a small amount of pollution and disturbance but in this site it is minimal.
Fishing areas and conservation of fish stocks
The site serves as a refuge to commercial fish such as tunas, snappers, billfish and sharks, helping to protect their already pressured populations. The site also provides breeding grounds for the Clarion Angelfish which is used in the aquarium trade.
Factors negatively affecting provision of this benefit
Pollution
Impact level - Low
Trend - Continuing
Overexploitation
Impact level - Low
Trend - Continuing
The sustainability of fishing in the surrounding waters of the site requires further study.
This unique site benefits science as well as limited tourism (principally diving). To a lesser extent it provides jobs, through park management as well as the naval base and diving operations. The site serves as a refuge to commercial fish such as tunas, snappers, billfish and sharks, helping to protect their already pressure populations. It also provides breeding grounds for the Clarion Angelfish which is used in the aquarium trade, however, commercial collections of this endemic fish should not be allowed in the National Park (IUCN Consultation, 2020).
Organization Brief description of Active Projects Website
1 Conservacion de Islas; CONANP The Grupo de Ecología y Conservacion de Islas, A. C. (GECI) started a feral cat control program on Socorro in 2011 which scaled up into an eradication campaign. Cats are now absent in many sectors of the island and their low population monitored.
http://www.revistas-conacyt.unam.mx/therya/index.php/THERYA/article/view/425
2 Mexico Pacific Project The Pacific Manta Research Group has been studying over 30 years the population of oceanic mantas who seasonally frequent Mexico’s Revillagigedos Islands.
http://www.mantatrust.org/welcome-to-the-mexico-pacific-project/.
3 CONANP, Conservacion de Islas, GEF “Aumentar las capacidades de México para manejar especies exóticas invasoras a través de la implementación de la Estrategia Nacional de Especies Invasoras”. GEF Project 0081866
http://www.biodiversidad.gob.mx/especies/Invasoras/gef/pdf/2.1-1-reporte-extenso-gef-2015.pdf
4 CONANP, UNDP, GEF Optimizar la efectividad de las Áreas Naturales Protegidas en México para contribuir a la conservación de especies en riesgo.
http://www.mx.undp.org/content/mexico/es/home/operations/projects/environment_and_energy/especies-en-riesgo-gef.html
5 CONANP, Mohamed bin Zayed Foundation Socorro Island Dove project. Reintroduction of this species to Socorro.
https://www.xataka.com.mx/ciencia/el-proyecto-paloma-de-socorro-busca-restablecer-la-biodiversidad-en-las-islas-mexicanas
6 Pelagios-Kakunjá Studies on the connectivity, movements, migratory patterns and residence of sharks and mantas using telemetry; shark abundance, distribution and diversity of sharks using Baited Remote Underwater Systems and censusing; connectivity and population structure of sharks using genetics.
http://pelagioskakunja.org/archipielago.html
7 SCRIPPS. Institute of Oceanography. Study of telemetry in manta rays to determine patterns of movement and population structure of individuals.
http://scrippsscholars.ucsd.edu/maburto https://scripps.ucsd.edu
8 Whale Shark Mexico/Conexiones Terramar A telemetry project to evaluate migratory patterns of whale sharks in the Gulf of California and surrounding areas. Through the technique of mark-recapture and the use of satellite tagging and photographic-identification, we will determine the giant manta (Mobula birostris) movements in the Eastern Pacific to know its connectivity with other areas. Performing underwater ultrasonography technique will allow us to verify the gestational stage and the degree of embryonic development to confirm and strengthen the habitat protection for the conservation of the species.
http://www.whalesharkmexico.com/research/
9 MigraMar Founded in 2006, MigraMar is a network of scientists working on research and conservation of migratory marine species in the region of the Eastern Pacific. Its goal is to implement effective plans for management and conservation that are in keeping with the nature of these creatures.
www.migramar.org
10 Pelagic Life This study will employ the use of satellite tags to record movements of Whale Sharks (Rhincodon typus) and Oceanic Giant Mantas (Mobula birostris) from the UNESCO World Heritage Site Revillagigedo National Park, the Gulf of California and the Thetis Bank off the coast of the Baja California Peninsula, to assess the extent to which these charismatic fishes occur in protected areas, offshore seamounts and their migratory pattern. Our results will help in generated conservation efforts.
http://www.pelagiclife.org/migracionespelagicas

References

References
1
Aburto-Oropeza, O., Ballesteros, E., Ezcurra, E., Friedlander, A., Henning, B., Hoyos, M., Johnson, A.F., Mascareñas-Osorio, I., Mayorga, J.S., Muñoz, A., Salinas de León, P., Sánchez-Ortiz, C., Thompson, C. & E. Salas (2017). Informe Técnico Archipiélago de Revillagigedo: Biodiversidad, Amenazas y Necesidades de Conservación. National Geographic Pristine Seas, Mares Mexicanos. 32 pg. Available at <https://reservarevillagigedo.files.wordpress.com/2017/09/ar…; [Accessed 15 May 2020].
2
Aguirre-Muñoz, A., Samaniego-Herrera, A., Luna-Mendoza,L., Ortiz-Alcaraz, A., Rodríguez-Malagón, M., Méndez-Sánchez, F., Félix-Lizárraga, M., Hernández-Montoya, J.C., González-Gómez, R., Torres-García, F., Barredo-Barberena, J.M. & Latofski-Robles, M. (2011). Island restoration in Mexico: ecological outcomes after systematic eradications of invasive mammals. In: Veitch, C. R.; Clout, M. N. & Towns, D. R. (eds.). Island invasives: eradication and management. IUCN, Gland, Switzerland. Pp. 250-258.
3
Aldana-Moreno A, Hoyos-Padilla M, González-Armas R, Galván-Magaña F, Hearn A, A. Peter Klimley, Winram W, Becerril-García E, Ketchum JT (2019) Residency and diel movements of the endangered scalloped hammerhead Sphyrna lewini in the Revillagigedo National Park. Journal of Fish Biology 2020:1-6. DOI: 10.1111/jfb.14239
4
Baske, A. (2007). Can Recreational Diver Surveys Lead to Conservation Action? A Case Study of the Revillagigego Archipelgo. UC San Diego: Center for Marine Biodiversity and Conservation. Retrieved from https://escholarship.org/uc/item/71s470sp
5
Becerril-García EE, Hoyos-Padilla EM, Henning B, Salinas-De León P. Sharks, rays, and chimaeras of the Revillagigedo National Park: An update of new and confirmed records. J Fish Biol. 2020;1–6. https://doi.org/10. 1111/jfb.14457
6
Blue Parks (2020) Evaluation Report Parque Nacional Revillagigedo. Blue Parks. 16 pg.
7
CONANP (2007). Programa de conservación y manejo. Reserva de la Biosfera Archipiélago de Revillagigedo. Ciudad de Mexico, Mexico. National Commission of Natural Protected Areas. 219 pp. Available at <http://www.dof.gob.mx/nota_detalle_popup.php?codigo=5008088…; [Accessed 15 May 2020].
8
CONANP (2018). Programa de Manejo Parque Nacional Revillagigedo. Ciudad de Mexico, Mexico: CONANP. pp. 328. Available at: <https://simec.conanp.gob.mx/pdf_libro_pm/82_libro_pm.pdf>; [Accessed 15 May 2020]
9
Comité Asesor Nacional sobre el Territorio Insular Mexicano (2012). Estrategia Nacional para la Conservación y el Desarrollo Sustentable del Territorio Insular Mexicano. Secretaría de Medio Ambiente y Recursos Naturales, Instituto Nacional de Ecología, Comisión Nacional de Áreas Naturales Protegidas, Secretaría de Gobernación, Secretaría de Marina-Armada de México y Grupo de Ecología y Conservación de Islas, A.C. México, D.F. y Ensenada, B.C. 125 pp. ​​​​​​ Available at: <http://cambioclimatico.gob.mx:8080/xmlui/handle/publicacion…; [Accessed 15 May 2020].
10
Fourriére M, Reyes-Bonilla H, Ayala-Bocos A, Ketchum JA, Chávez-Comparan JC. Checklist and analysis of completeness of the reef fish fauna of the Revillagigedo Archipelago, Mexico. Zootaxa. 2016 Aug;4150(4):436-466. DOI: 10.11646/zootaxa.4150.4.4.
11
IUCN (2016). World Heritage Nomination – IUCN Technical Evaluation Archipiélago de Revillagigedo (Mexico). [online] Available at: <whc.unesco.org/en/list/1510/documents/> [Accessed 15 May 2020].
12
IUCN Consultation (2020). IUCN World Heritage Confidential Consultation form: Respondent 1. Archipielago de Revillagigedo, Mexico.
13
Ketchum JT, Hoyos-Padilla M, Aldana-Moreno A, Ayres K, Galván-Magaña F, Hearn A, Lara-Lizardi F, Muntaner-Lopez G, Grau M, Trejo-Ramírez A, Whitehead D, Klimley AP (2020). Shark movement patterns in the Mexican Pacific: A conservation and management perspective. In: S. Larson & D. Lowry (Eds.), Conservation of Mexican Sharks, Advances in Marine Biology. London, UK: Academic Press
 
14
Ortiz-Alcaraz, A., Aguirre-Muñoz, A., Méndez-Sánchez, F., Rojas-Mayoral, E., Solís-Carlos, F., Rojas-Mayoral, B., Benavides-Rios, E., Hall, S., Nevins, H. & A. Ortega-Rubio (2019). Ecological restoration of Socorro Island, Revillagigedo Archipelago, Mexico: the eradication of feral sheep and cats. In: C.R. Veitch, M.N. Clout, A.R. Martin, J.C. Russell and C.J. West (Eds). Island invasives: scaling up to meet the challenge, Occasional Paper SSC no. 62. Gland, Switzerland: IUCN. pp.267-273.
15
Reyes Bonilla H, Ketchum JT, Cupul Magaña A, Alvarez del Castillo A, Lozano Horcasitas A (2015) Evaluación de la capacidad de carga para buceo en la Reserva de la Biósfera Archipiélago Revillagigedo. UABCS-Pelagios Kakunjá-UdeG
 
16
Ruiz-Guerra, B., Aguilar-Chama, A., de León, S. G., & Guevara, R. (2019). Invasive Species Appear to Disrupt the Top-Down Control of Herbivory on a Mexican Oceanic Island. Pacific Science, 73(1), 1-16.
17
State Party of Mexico (2015). Nomination of Archipiélago de Revillagigedo [online]. National Comission of Natural Protected Areas (CONANP) and the Secretariat of the Environment and Natural Resources (SEMARNAT). Available at: <whc.unesco.org/en/list/1510/documents/> [Accessed 15 May 2020].
18
State Party of Mexico. (2018). Report of the State Party to the World Heritage Committee on the state of conservation of the Archipiélago de Revillagigedo (Mexico). [online] Mexico: SEMARNAT. Available at: https://whc.unesco.org/en/list/1510/documents/ [Accessed 15 May 2020].
19
Stewart JD, Hoyos-Padilla EM, Kumli KR, Rubin RD. Deep-water feeding and behavioral plasticity in Manta birostris revealed by archival tags and submersible observations. Zoology. 2016;119(5):406-413. doi:10.1016/j.zool.2016.05.010
20
World Heritage Committee (2016) Decision 40 COM 8B.14. Archipiélago de Revillagigedo (Mexico). In: Decisions Adopted by the World Heritage Committee at its 40th Session (Istanbul, 2016). [online] Paris, France: UNESCO World Heritage Centre. Available at: <http://whc.unesco.org/en/list/1510/documents/>; [Accessed 15 May 2020].

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