Mexico on Track to Protect 30% of Its Marine Area by 2030

Abstract

Mexico has committed to protecting 30% of its marine territory by 2030 to comply with Target 3 of the Kunming–Montreal Global Biodiversity Framework, adopted during the 15th Conference of the Parties to the Convention on Biological Diversity. In this paper, we demonstrate the feasibility of meeting this commitment by determining the marine extent of conservation measures based on legally established Marine Protected Areas and areas that meet the criteria to be considered as Other Effective area-based Conservation Measures (OECMs) and determining the marine extent of areas proposed in various conservation planning exercises that can be created as any of the area-based instruments that exist in Mexico. The total coverage of existing and proposed areas was calculated by merging the dataset to remove duplicates and dissolving the boundaries between polygons to determine the total area. Spatial analysis was carried out in ArcGIS using geoprocessing tools. Currently, more than 25% of Mexico’s marine area is legally protected or conserved, with federal marine protected areas covering more than 22% of the Exclusive Economic Zone. The legally established areas that can be considered OECMs cover about 3% of the marine territory. We found that more than 9% of Mexico’s Economic Exclusive Zone contains areas of high conservation importance that are not covered by any area-based instrument. This study shows that Mexico has the potential to protect or conserve 32.8% of its marine territory by 2030.

1. Introduction

The oceans cover more than 70% of the Earth’s surface and support more than 80% of the planet’s biodiversity [1]. They stabilize the climate, absorbing about 30% of the excess carbon dioxide emissions released into the atmosphere and more than 90% of the heat from global warming [2,3]. The oceans support more than 3.5 billion people who depend on the sea as their main source of food or income [4].

Despite the importance of the oceans to life on Earth, marine ecosystems are being severely degraded by human activities. Overexploitation, pollution, invasive alien species, coastal development and the effects of climate change are among the main causes of the decline in the health of the oceans [5]. Some of these disturbances, especially the local ones, can be managed through area-based conservation measures in marine regions, such as Marine Protected Areas (MPAs) and Other Effective Area-based Conservation Measures (OECMs) or Conservation Areas.

The effectiveness of area-based conservation measures in sustaining populations of threatened species and promoting the health of ecosystems has put these areas in the spotlight in addressing the global biodiversity crisis. Aichi Target 11, included in the Strategic Plan for Biodiversity 2011–2020, established the target of protecting at least 17% of terrestrial and 10% of marine and coastal areas by 2020 [6]. In the recently adopted Kunming–Montreal Global Biodiversity Framework (GBF), the third target promotes the conservation of 30% of the world’s terrestrial, marine and coastal areas by 2030 [7].

MPAs are the most traditional and widespread tool for marine biodiversity conservation, and their number has increased worldwide over the last 30 years [8]. The International Union for the Conservation of Nature (IUCN) has defined an MPA as “a clearly defined geographical space, recognized, dedicated, and managed through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values” [9]. There are currently over 18,400 MPAs worldwide. They protect more than 29 million square kilometers of the ocean [10]. Conserved areas have recently been defined as OECMs in Decision 14/8 of COP 14 of the CBD. An OECM is “a geographically defined area other than a Protected Area, which is governed and managed in ways that achieve positive and sustained long-term outcomes for the in-situ conservation of biodiversity, with associated ecosystem functions and services and, where applicable, cultural, spiritual, socioeconomic, and other locally relevant values” [11]. By addressing local threats, these area-based conservation tools can increase the resilience of marine ecosystems to global threats, particularly those associated with climate change [12].

Mexico is a megadiverse country, with three-quarters of its territory being marine [13]. The Territorial Sea (234,317 km² or 23,431,700 ha) and the Exclusive Economic Zone (EEZ) (2,879,678 km² or 287,967,800 ha) belong to the Mexican marine zones under federal jurisdiction [14]. The latter comprises the strip of the sea measured from the outer limit of the territorial sea to a maximum distance of 200 nautical miles offshore, counted from the baseline from which the width of the territorial sea is measured. The inner limit of the EEZ coincides identically with the outer limit of the Territorial Sea [15]. The Mexican coasts extend for 12,022 km (8210 km in the Pacific Ocean, 2268 km in the Gulf of Mexico and 1544 km in the Caribbean Sea), for which the conservation of marine and coastal areas is a national priority [16].

Numerous area-based conservation strategies have been implemented in Mexico’s marine territory, with federal MPAs, managed by the National Commission of Natural Protected Areas (CONANP), being the most traditional and well known [17]. Over the last 40 years, the number, size, and effectiveness of the country’s MPAs have increased, with 37 MPAs now covering over 69 million hectares of Mexico’s ocean. [18] Areas that can be considered OECMs [19], such as fishing refuges and marine species reserves, are less widely implemented and less well known. The proper management of these areas and their expansion in Mexican waters is highly relevant to ensure the conservation of Mexican marine biodiversity.

The high level of biodiversity in Mexico, at all three levels (genes, species, and ecosystems), has resulted in a wide variety of landscapes of great scenic beauty [12], which has contributed to the recognition of many Mexican sites by international organizations such as UNESCO. These sites, along with others of global importance from different countries, are included in the List of Wetlands of International Importance (Ramsar List), the World Network of Biosphere Reserves of the MAB Program and the List of World Heritage Sites. The international recognition of these areas, proposed by the Mexican government, places them as priority areas for conservation. By proposing this recognition, the Mexican government has assumed the responsibility of preserving them and maintaining the values that made this recognition possible in the first place.

Many of these sites in Mexico are fully or partially included in MPAs [18]. However, those that are not included can be proposed as OECMs as they meet the four necessary criteria defined by the IUCN-WCPA [20]. Criterion “A” is the “Area is not currently recognized as a protected area”. Criterion “B”, the “Area is governed and managed”, is in principle fulfilled since the government acquired the commitment to preserve it when proposing it. The same applies to Criteria “C”, the area “Achieves sustained and effective contribution to in situ conservation of biodiversity”, and “D”, the area possesses “Associated ecosystem functions and services and cultural, spiritual, socio-economic and other locally relevant values”, which in principle are necessary criteria to propose them to the different networks and conventions.

This work aims to demonstrate that at least 30% of the Mexican EEZ has the potential to be protected by 2030, considering the commitment to protect 30% of the marine territory by 2030, as proposed in Target 3 of the GBF of the CBD. To this end, we describe the different area-based conservation instruments currently applied in Mexico, including their conceptualization, in accordance with the legislation and associated bibliography. We estimate their coverage to determine the current marine protected and conserved area of the country. Finally, we analyze several proposals identified in different planning exercises that we suggest could be evaluated for approval under area-based instruments, both MPAs and OECMs, to achieve the ambitious conservation goal known as 30 × 30.

2. Materials and Methods

2.1. Current Status of the Area-Based Conservation Instruments in Mexico

To determine the total MPA coverage and areas that meet the OECM criteria, a spatial analysis was performed with ESRI’s ArcGIS software, using geoprocessing tools (ArcMap 10.8.1). All legally approved sites with extensions in the Mexican marine territory up to the outer limit of the EEZ were analyzed. Supplementary Materials Table S1 includes the sources of information for the dataset used in the analyses. The MPAs evaluated were federal and state. At the national level, we considered fishing refuges and refuge areas for the protection of marine species as OECMs. At the international level, we analyzed as OECMs those recognized by international conventions: Wetlands of International Importance or Ramsar sites, Biosphere Reserves and World Heritage sites.

To determine the percentage of the Mexican EEZ currently protected or conserved, each dataset (from Supplementary Materials Table S1) was intersected with the EEZ polygon to remove the terrestrial extension of MPAs and OECMs, thus discarding coastal protected areas without marine coverage. For the calculation of the total coverage of area-based conservation measures in the Mexican marine area, the datasets were merged into a single dataset. This allowed us to eliminate duplicity derived from existing overlaps between protected and conserved area polygons, for example, in areas designated with more than one category, such as MPAs, World Heritage Sites or Ramsar Sites, etc. Finally, the boundaries between the polygons were dissolved to determine the total area.

2.2. Proposals of New Areas to Be Considered MPAs or OECMs

In order to estimate a possible scenario for the protection of 30% of the Mexican marine area, this paper considered several areas identified in various conservation planning exercises (Supplementary Materials Table S2). These areas were determined according to (1) the Priority Marine Sites for the Conservation of Biodiversity [21], (2) the Priority Conservation Areas from Baja California to the Bering Sea [22,23], (3) the areas resulting from the Ecoregional Planning Exercise for Marine Conservation: Gulf of California and Western Coast of Baja California Sur [24], (4) the Proposal for Marine Protected Areas in the Great Islands Region of the Gulf of California [25]. We also analyzed the CONANP’s proposal of a new MPA, (5) the Sea of Cortéz and the Southern Californian Pacific Biosphere Reserve [26]. All these areas could be considered for approval as MPAs or OECMs in Mexico.

The possible conservation scenario for Mexico in 2030, proposed in this paper, is derived from the spatial union of all currently approved area-based conservation instruments in Mexico: the MPAs, the OECMs, and the areas proposed in the different planning exercises. As in the current situation, these areas were merged to calculate the total area of the final proposal.

3. Results

3.1. Current Status of Area-Based Conservation Instruments in Mexico

3.1.1. Marine Protected Areas

Federal MPAs

Federal MPAs (Figure 1; Supplementary Materials Table S3) were defined as those in which the original environment has not been substantially modified and which are dedicated to the protection, conservation and maintenance of biological diversity and its associated natural and cultural resources [27]. The federal MPAs are established by presidential decree or through the certification of an area whose owners are willing to dedicate it to conservation. The management of their biological heritage is the responsibility of CONANP, and the activities allowed within their boundaries are defined in the General Law of Ecological Balance and Environmental Protection [27].

The first federal MPA was established in Cabo San Lucas in 1973. From 1992, MPAs gradually increased, at a rate of between one and four almost every year. By 2012, more than 4 million hectares of MPAs had been established [18]. In 2016, the expansion of MPAs within the Mexican EEZ increased significantly with the creation of the Mexican Caribbean, Pacific Islands of the Baja California Peninsula and Deep Mexican Pacific Biosphere Reserves, as well as the Revillagigedo National Park, which together totaled more than 65 million hectares of protected area.

Currently, 37 federal MPAs have been established in Mexico, protecting in total 69,458,613.21 marine hectares [18], which represents 22% of Mexican EEZ. Of these: 31 protect marine and coastal ecosystems and only six are exclusively marine; 16 are Biosphere Reserves, 14 are National Parks, six are Flora and Fauna Protection Areas and one is a sanctuary, corresponding to four of the six management categories that exist in Mexico [18]. Biosphere Reserves are also the most extensive within the EEZ, covering 17% of the territory.

State MPAs

The different states and their municipalities can create and manage protected areas in the areas under their jurisdiction. However, since almost all of Mexico’s marine territory is under federal jurisdiction, state MPAs are limited to coastal and marine areas considered inland waters (e.g., bays and coastal lagoons, etc.).

These MPAs are created by decree according to the administrative level that promotes them (state or municipal), and the activities permitted are established according to the General Law of Ecological Balance and Environmental Protection [27], the ecological planning programs and their management programs. State MPAs are subject to special protection, conservation, restoration, and development regimes, according to the management categories established in the legislation that promotes them. Of the current seven State MPAs in the marine coastal area (covering a total of 407,876.31 ha), only 149,416.67 ha are marine, which represents 0.05% of Mexican EEZ (Figure 1; Supplementary Materials Table S4).

3.1.2. Other Effective Area-Based Conservation Measures (OECMs)

Fishing Refuges

Fishing refuges are areas recognized by the General Law on Sustainable Fisheries and Aquaculture and are devoted to conserving and contributing, naturally or artificially, to the development of fishery resources [28]. These area-based conservation instruments are designed to contribute to the conservation of fish species, the protection of reproduction and nursery processes, repopulation, larval dispersal, growth, and the recovery of food webs and habitats [28].

The implementation of the Fishing Refuges began in 2012 with the decree of the San Cosme Punta Coyote Corridor, Gulf of California. This network of 11 Fishing Refuges was promoted by the government and civil society organizations, with the full participation of fishing communities [29]. There are currently 36 fishing refuges in marine waters under federal jurisdiction in Mexico, with a total area of 2,051,079.05 ha, representing 0.65% of Mexican EEZ (Figure 2; Supplementary Materials Table S5) [30].

In the case of temporary fishing refuges, at the end of their five-year term, communities may propose a renewal, as well as changes in size and location [31]. Regulations in the zones may include total or partial closures, aimed at prohibiting certain fishing activities or the use of certain fishing gear [32].

Refuge Areas for the Protection of Marine Species (Species Refuges)

The refuge areas for marine species (Species Refuges), other than MPAs, are governed and managed to achieve positive and sustained long-term results for the conservation of biological diversity in situ. The creation of Species Refuges in waters under federal jurisdiction, federal maritime terrestrial zone, and floodplains, is recognized in article 65 of the General Wildlife Law of Mexico [33]. These areas are created individually to guarantee the conservation of threatened species, included in the IUCN Red List and the Mexican Official Standard (NOM-059-SEMARNAT-2010) [34], to protect their populations and the habitats they use in the different stages of their life cycles. The designation of these areas also contributes to the maintenance of associated ecosystem functions and services and, where appropriate, cultural, spiritual, socioeconomic, and other locally relevant values [33].

There are currently six Species Refuges and an area to regulate gear, systems, methods, techniques, and schedules for fishing activities (Figure 3; Supplementary Materials Table S6). These cover 3,782,962.05 ha and represent 1.3% of the Mexican marine space within the EEZ. The governance of these areas in general and fall within the responsibility of CONANP, although it is also carried out with the support of other governments and civil society institutions [33]. In addition, different academic institutions are also involved in the evaluation of the protected species populations [35,36,37,38].

3.1.3. Sites of International Relevance

RAMSAR Sites: The Convention on Wetlands of International Importance

Wetlands of International Importance or Ramsar sites are areas declared under the criteria established by the Convention on Wetlands of International Importance, especially as Waterfowl Habitat (IUCN). This convention, also known as the Ramsar Convention, is an intergovernmental treaty that establishes guidelines to promote actions in member countries and facilitate international cooperation for the conservation and sustainable use of wetlands and their resources [39].

The Ramsar Convention was approved on 2 February 1971 in the Iranian city of Ramsar and entered into force in 1975. Mexico adhered in 1986 by designating the “Wetland of Special Importance for the Conservation of Aquatic Birds Reserve Ría Lagartos”, coinciding with the Biosphere Reserve Ría Lagartos. The Mexican state has registered 144 wetlands before the convention [40], 80 of which are related to 69 federal MPAs (Figure 4; Supplementary Materials Table S7). To date, the total area of Mexican wetlands declared as Ramsar sites is 8,721,911 ha, and of this area, 2,503,108.38 ha correspond to marine territory in 37 sites, or 0.79% of Mexican EEZ.

In addition to recognition by the Ramsar convention, most Ramsar sites in Mexico are included under some national legal figure of protection, being MPAs the most common, for marine and coastal wetlands, so they have a good level of enforcement [41]. However, there are other Ramsar sites that, although some type of management is carried out by local authorities, need to be recognized under some national conservation instrument based on areas [42].

Biosphere Reserves: Man and the Biosphere (MAB) Programme—UNESCO

Biosphere Reserves, defined as “learning places for sustainable development”, are sites where changes and interactions between social and ecological systems are addressed, including conflict prevention and biodiversity management [43]. These areas include terrestrial, marine, and coastal ecosystems. Each site promotes local solutions to global challenges that combine the conservation of biodiversity with its sustainable use and the restoration of ecosystem services [44].

Biosphere Reserves are nominated by national governments and remain under the sovereign jurisdiction of the states where they are located [45]. Upon verifying their applicability, they are designated within the framework of the intergovernmental MAB Program, and their status is internationally recognized [46]. Currently, there are 738 biosphere reserves in 134 countries, including 22 transboundary sites [47].

Mexico is the country with the largest number of Biosphere Reserves in the Americas and the third largest in the world after Spain and Russia [47]. With 41 sites designated as biosphere reserves, the marine coastal area in Mexico recognized under this international figure is 12,200,897.89 ha.

All biosphere reserves are also declared federal protected areas, so they have all the legal support and are therefore managed by CONANP [48]. As a result, of the 11 marine biosphere reserves in Mexico recognized by UNESCO (Figure 4; Supplementary Materials Table S8), all or a large part of their territories are included in federal MPAs. Mexico has also adopted Biosphere Reserves as one of its categories of protected natural areas [49]. However, not all of these MPAs fall under the category of Biosphere Reserves established by CONANP. Such is the case of the Arrecife de Alacranes and Huatulco national parks, which have also been recognized by UNESCO as biosphere reserves.

Sian Ka’an was the first Biosphere Reserve including marine territory created in Mexico in 1986 and is located in the Mexican Caribbean, in the state of Quintana Roo. The area of the 11 Mexican coastal and marine biosphere reserves is 6,195,351.56 ha, of which 2,289,424.43 ha are located in the Mexican marine waters, representing 0.7% of the Mexican EEZ.

Natural World Heritage Sites—UNESCO

A World Heritage Site is an area proposed by governments and designated by UNESCO as having an outstanding universal value for humanity [50]. These sites are inscribed on the World Heritage List for future generations, regardless of the territory in which they are located [51]. To date, there are 1154 places of natural and cultural values, of 167 state parties, inscribed on the World Heritage List [52].

The States Parties are required to submit periodic reports on the state of conservation and the various protection measures implemented at their sites [53]. These reports allow the World Heritage Committee to assess conditions at the sites and eventually decide on the need for specific measures to resolve recurring problems, including the inscription of a site on the List of World Heritage in Danger [54].

In Mexico, the four declared Natural World Heritage sites with marine extension are Federal MPAs, so they are managed by CONANP and have the corresponding legal support [55]. The area of the four sites is 3,371,510.38 ha, of which 2,371,615.88 ha are located in the Mexican marine area up to the limits of the EEZ, representing 0.75% of it (Figure 4; Supplementary Materials Table S9).

The first Mexican marine natural site inscribed on the World Heritage list was Sian Ka’an, in 1987. This important area, in addition to being a federal MPA, belongs to the internationally recognized category of Wetland of International Importance under the Ramsar Convention and Biosphere Reserve by UNESCO’s MAB Program. The other two areas are the Whale Sanctuary of El Vizcaino, which was inscribed on the heritage list in 1993, and the Revillagigedo Archipelago inscribed in 2016, both also federal MPAs and within the international category of UNESCO’s MAB Biosphere Reserve Program.

Finally, the Islands and Protected Areas of the Gulf of California World Heritage site, inscribed in 2005, was added to the list of World Heritage in Danger in 2019. This decision was based on the imminent extinction of the Vaquita porpoise (Phocoena sinus), which, as noted above, is endemic to the Gulf of California [56]. The failure to stop illegal gillnet fishing in the upper Gulf of California has led to the near extinction of the Vaquita. The World Heritage Convention recognizes that much of the site and many key species and habitats remain well conserved. However, despite efforts to strengthen law enforcement and monitoring, illegal fishing continues to affect the site [52].

3.2. Proposals of New Areas to Consider as MPAs and OECMs

Several planning exercises have been carried out to identify priority areas for marine conservation in Mexico (Figure 5). These evaluations have repeatedly confirmed the importance of the different areas recognized as existing conservation instruments (MPAs and OECMs). In this context, the importance of numerous marine regions of the country has also been recognized, although for different reasons have not been included in any area-based conservation instrument.

3.2.1. Priority Marine Sites for Biodiversity Conservation

A gap analysis for the conservation of marine biodiversity led by CONABIO [21] identified 105 priority sites for the conservation of coasts, oceans, and islands in Mexico, using digital thematic cartography and databases of georeferenced records of flora and fauna species. In this analysis, the Gulf of California ecoregion stood out with the highest proportion in potential priority areas and the number of priority sites. Likewise, for the first time, 26 deep-sea sites were identified and documented, such as las Ventilas Hidrotermales de la Cuenca de Guaymas y de la Dorsal del Pacífico Oriental.

The 105 priority sites cover an area of 34,229,923.48 ha, of which 28,117,582.11 ha is located in the marine area, representing 8.9% of the Mexican EEZ. Of the 105 priority sites identified, there are still 15,756,579.45 ha that has not been included under any area-based conservation instrument (MPA or OECMs), which can be assessed for the expansion of existing areas or the creation of new ones. This exercise identified 49 marine endemic species in Mexico, highlighting the importance of protecting the Upper Gulf of California by the presence of the two most prominent endemic species: the Vaquita porpoise listed as Critically Endangered [57] in the UICN Red List and the Totoaba (Totoaba macdonaldi) listed as Vulnerable [58] in the UICN Red List.

3.2.2. Marine Priority Conservation Areas from Baja California to the Bering Sea

The Commission for Environmental Cooperation (CEC), as part of its Strategic Plan for Cooperative Conservation of Biodiversity in North America, led the initiative for identification of Priority Conservation Areas (PCAs). These areas are highly relevant to the three countries (Mexico, United States, and Canada), due to their relevance, their threatened nature, and the opportunities for their conservation, whose effective preservation requires bi- and tri-national collaboration measures [23]. This PCA initiative was intended to determine where immediate conservation action is needed, thereby charting the way for future partnerships for conservation and action in the Baja California to Bering Sea region.

The western coast of North America is home to unique and important shared marine environments. The region is also home to a large number of shared marine species (including Pacific gray and blue whales, leatherback sea turtles, common tuna, collared geese, and sooty gulls) that migrate thousands of kilometers across national borders, without hesitation [22]. Thus, whether by species or shared ecosystems, the marine environments of Canada, Mexico, and the United States are intrinsically linked.

In this exercise, twenty-eight marine priority areas were defined for conservation in North America, 11 located in Mexico’s marine territory with an area of 6,601,462.49 ha, representing 2% of the Mexican EEZ. Of the areas identified in Mexico, 3,039,201.39 ha are included in some conservation figures based on areas. The remaining unprotected territory (3,562,261.10 ha) corresponds to 1.1% of Mexico’s marine territory. The implementation of new conservation instruments based on areas in these sites would guarantee the conservation of species of national, but also regional and global relevance.

3.2.3. Ecoregional Planning for Marine Conservation: Gulf of California and Western Coast of Baja California Sur

This exercise was carried out for the region of the Gulf of California and the western coast of Baja California Sur by Comunidad y Biodiversidad, A.C. (COBI), with funding from The Nature Conservancy (TNC). The analyzed region is characterized by a high biodiversity, a unique variety of habitats, and a high level of threats to its conservation [24].

For this analysis process, the authors compiled spatial databases (~45,000 records) of species, ecosystems, physical-biological processes, and human uses of natural resources that negatively affect species and ecosystems. These data were provided by different researchers and others came from previous planning processes. Then, using the MARXAN program, they determined a portfolio of 54 priority sites for conservation, which correspond to 14% of this marine ecoregion. These 54 sites cover a total area of 8,627,500.00 ha, of which 7,261,810.12 ha are in the maritime area and represent 2.3% of the Mexican EEZ. Until now, 5,812,944.66 ha remains unprotected, and can be assessed to be included in any area-based conservation measure (MPAs or OECMs.)

3.2.4. Design of Marine Reserves in the Large Islands Region of the Gulf of California

Alvarez-Romero et al. [25] developed a framework for the design of marine reserve networks based on both conventional (designed to represent only species and ecosystems) and graph-theoretical approaches (designed to maximize species connectivity under current and warming scenarios of the oceans). This framework was implemented in the Gulf of California, where the authors subsequently compared the ecological suitability of marine reserve networks, considering the size of the individual reserve and the area of distribution of selected focal species, the connectivity, and opportunity costs of implementing reserve networks.

The three network proposals resulted in: (a) 70 reserves that consider the representation of species distributions and ecosystems assuming uniform connectivity; (b) 59 reserves that consider larval connectivity in the current scenario; (c) 74 reserves representing connectivity in a 3 °C global warming scenario, can be taken as a basis for expansion or creation of new area-based conservation figures in the Gulf of California. However, taking into account that the patterns of dispersal and connectivity can change significantly under scenarios of warming of the oceans, probably proposal (c) would be the best starting point. The proposals of this exercise cover a total area of 67,500 ha, of which 49,226 ha is located in marine territory, representing 0.02% of the Mexican EEZ. To date, 15,882.02 ha has not been included in any area-based conservation figure, so it can be assessed for inclusion in existing MPAs or OECMs, or in new areas to be created, on the basis of their importance.

3.2.5. Biosphere Reserve Proposal: Sea of Cortez and Pacific of Baja California Sur

The proposal to create a Biosphere Reserve in the Sea of Cortez and Pacific Area of the State of Baja California Sur (Figure 6) responds to the urgent need to protect marine ecosystems vital to Mexico and the planet, as well as to promote economic benefits in the region. The proposal includes two relevant zones: a buffer zone of more than 100,000 km² of marine area where coastal fishing, sport fishing and tourism-related activities would be allowed. There would also be a core zone of about 90,000 km² where no extractive activities would be allowed [26].

The area of the Sea of Cortez and Southern Californian Pacific Biosphere Reserve is 194,888,644.95 ha, representing 6.07% of the Mexican EEZ. Of this area, 5.4% of the Mexican EEZ (17,255,694,18 ha) is not currently included in any area-based conservation figure, so its creation would be an important leap forward in the conservation of Mexico’s marine resources.

4. Discussion

The implementation of area-based conservation tools in Mexico has evolved favorably, with increased coverage of marine ecosystems and associated species of regional and global importance. The Aichi Target 11 and Target 14.5 of the SDG 14 Life below Water were more than doubled by 2020 [59], putting Mexico in a good position to meet the commitment to conserve 30% of its marine areas, acquired with the adoption of the GBF. Until now, the federal MPAs occupied first place in the amount of marine territory protected, with 69,458,613.21 ha in 50 years of evolution (

Table 1. Mexican area-based conservation measures approved and proposed, based on conservation planning exercises in Mexican EEZ.

Mexican Area-Based Conservation Measures (Approved and Proposed)	Marine Extension (ha)	Percentage (%) within the Mexican EEZ	Percentage (%) of the Mexican EEZ Not Already Included in Any Area-Based Conservation Measure
Federal MPAs (approved)	69,458,613.20	22.00%
State MPAs (approved)	149,416.67	0.05%
Fishing Refuges (approved)	2,033,641.38	0.65%
Refuge areas for the protection of marine species (approved)	3,782,962.05	1.30%
RAMSAR sites (approved)	2,503,108.38	0.79%
Biosphere Reserves—UNESCO (approved)	2,289,424.42	0.70%
Natural World Heritage Sites—UNESCO (approved)	2,371,615.88	0.75%
Priority marine sites for biodiversity conservation—CONABIO (proposed)	28,117,582.11	8.90%	4.95%
Marine Priority Conservation Areas from Baja California to the Bering Sea (proposed)	6,601,462.49	2.00%	1.12%
Ecoregional planning for marine conservation: Gulf of California and western coast of Baja California Sur (proposed)	7,261,810.11	2.30%	1.83%
Design of marine reserves in the Large Islands Region of the Gulf of California (proposed)	49,226.00	0.02%	0.01%
Biosphere Reserve Proposal: Sea of Cortez and Pacific of Baja California Sur (proposed)	19,291,159.02	6.07%	5.43%
Total area (ha) with overlap	143,927,460.11
Total area (ha) without overlap	104,232,000.32
Total extension (ha) of the EEZ	317,765,500.00
Total percentage (%) of the EEZ		32.80%
Total percentage (%) of the EEZ not already included in any area-based conservation measure	30,901,874.32		9.72

). The creation of federal MPAs of great extension in the years 2016 and 2017 stands out [18].

The contribution of state MPAs to the protection of marine areas has been small (Table 1), considering that almost all marine areas are under federal jurisdiction. However, there are important sites in bays and coastal lagoons, such as the Manatee Sanctuary in Chetumal Bay, Quintana Roo [60]. This area promotes the conservation of marine and coastal ecosystems, in addition to the protection of this mammal species, cataloged as Vulnerable by the IUCN [61]. States and municipalities should promote efforts to increase the protected marine area under their jurisdiction through the various existing area-based conservation figures.

More recently, other area-based conservation figures have emerged, where refuge areas for the protection of marine species (Species Refuges) occupy a larger area (Table 1). We highlight the case of the Species Refuges created for the protection of the Vaquita porpoise, an endemic and Critically Endangered Species [57], with an estimated population of only 10 individuals [62]. The decline of this species has been associated primarily with their incidental capture in nets used to capture the Totoaba, a fish species also endemic to the Gulf of California with high commercial value [63].

To conserve this species, whose distribution area is included mostly in the Upper Gulf of California, the Species Refuge area for the protection of the Vaquita was created in 2005, defining an area within the Biosphere Reserve Upper Gulf of California and the Colorado River Delta Biosphere Reserve and another outside [64]. Later in 2020, after recognizing the dramatic decline of the population of the Vaquita, the Zero Tolerance Area was created within the refuge area for the protection of the Vaquita [65]. In this zone, coordinated enforcement between different government institutions including CONAPESCA, PROFEPA, and CONANP, was increased to effectively protect the populations of the Vaquita. In addition, a larger area was created that same year for the protection of the Vaquita, in which gears, methods, techniques, and schedules for fishing activities are regulated (Figure 3; Supplementary Materials Table S6) [65]. Unfortunately, the populations of the Vaquita porpoise do not show signs of recovery so far [66]. However, some authors remain hopeful, based on population viability analyses that which suggest a high probability of population recovery if the bycatch of vaquita is immediately eliminated [67,68].

Fishing reserves, although newer and smaller, are emerging as a promising form of participatory fisheries management, involving local communities (Table 1) [69]. Its implementation has been very successful, as fishermen and local communities have drafted and negotiated the proposals, with the support of NGOs and government institutions. Fishermen are also actively involved in enforcement and monitoring [70]. The application of the Fishing Refuges has contributed to increasing the volume and value of the catch in the surrounding areas and to the certification of sustainable fishing [69]. They have also supported the development of alternative activities (ecotourism), the maintenance of fishing activity, and greater active participation of the communities (co-management and governance). Currently, there are many initiatives promoted by the government, academia, and civil society, to support local communities in renovating and increasing the area of fishing refuges and to disseminate the good practices and lessons learned that have resulted from their application [71].

The existence in Mexico of numerous sites recognized by intergovernmental organizations, such as the Ramsar Convention, the Man and the Biosphere Programme (MAB) and the World Heritage Convention, reflects the importance of marine and coastal biodiversity in Mexico. Continuing to ensure the conservation of all these sites, which have been recognized for their importance not only to Mexico but also to the world, will allow Mexico to meet its international commitments under these agreements and achieve Target 3 of the GBF in relation to Mexico’s marine territory. Particular attention should be paid to areas not yet included in MPAs, either by including them in newly created MPAs or by recognizing them as OECMs.

Experts from various Mexican institutions have used a large amount of information on marine biodiversity to confirm the importance of existing MPAs and OECMs and to define new priority areas as candidates for new area-based instruments (Table 1). Different tools and methodologies have been used, considering the opinions of experts and the empirical knowledge of local people, such as fishermen and members of coastal communities.

Various geological, biogeographic, physiographic, lithological, socioeconomic, and ecological criteria have been used in the various conservation planning exercises discussed in this studio. These included the identification of sites with the greatest diversity, the greatest threats or ecosystems that met the criteria of high species richness, connectivity, or isolation [21,22,23,24,25]. More detailed criteria included the selection of sites that are representative and viable examples of an important ecosystem or habitat type, sites that are necessary for the sustainability of fisheries, sites with high species diversity including endemics, sites with ecological processes such as high productivity, recruitment or reproduction, sites that provide a specific habitat for one or more species, sites that are areas of cultural importance (historical, religious or recreational), sites that provide relevant environmental services and sites that are conducive to basic research and needs assessment [21,22,23,24,25]. The most recent conservation exercise discussed in this paper, presented by Álvarez-Romero et al. [25], included connectivity considerations and proposed different conservation alternatives, according to the different projected climate change scenarios (Table 1).

In these exercises, particular attention has been paid to the Gulf of California, an ecoregion characterized by high marine biodiversity [69]. In fact, two of the exercises are exclusively dedicated to the Gulf of California, and the proposal for the new Biosphere Reserve Sea of Cortez and Pacific of Baja California Sur corresponds to the marine extension of the state of Baja California Sur, with a large part in the interior of the Gulf of California. The core zone of this new area would be a large No-Take area, where the absence of extractive activities would favor the growth of species populations and the strengthening of marine ecosystems that are key to the region and the planet [26]. The proposal would promote greater equity in access to marine resources for coastal fleets, as the core zone will generate increases in biomass and spill-over effects, into the buffer zone, where they can be legally fished. The design of this area is based on an ecosystem approach to planning, which considers the relationship between fishing pressure and the region’s marine ecosystems. In addition to improving access to marine resources for coastal fleets, the reserve would also generate significant tourism and employment benefits by attracting more tourists interested in diving, sport fishing and marine ecotourism, among other activities [26].

From our analysis, we found that of the areas identified in the previous conservation planning exercises, 9.72% of the EEZ is still not included in any area-based conservation figure that is legally approved in Mexico or internationally recognized. This study does not provide a gap analysis, but rather highlights the areas that are not yet covered by any of the exercises addressed in this paper. The identified sites can be an important starting point for proposing new conservation area-based instruments, to increase up to 30% of the protected marine territory in line with the commitments adopted by Mexico in the framework of the GBF. Considering the species and ecosystems present, the existing threats (natural and anthropogenic, local, regional and/or global) and the level of priority given to each site in the conservation planning exercises, the Mexican national authorities can determine the conservation vocation of each of the sites concerned, with a view to defining under which conservation figure it is more appropriate for them to be declared. In addition, full consideration should be given to the importance of the sites for the traditional economic activities of local communities.

To properly address Target 3 of the GBF, new planning exercises need to be undertaken at the national level, or the information used to identify “Priority Marine Areas for Biodiversity Conservation” [21] needs to be updated. Planning should include considerations of marine connectivity and climate change adaptation and mitigation according to the different scenarios projected by the IPCC [72]. Future planning exercises should also consider the cultural and social relevance of the areas under study to local communities [73]. However, the planning exercises discussed in this paper are an excellent starting point to support new proposals that fulfill the GBF commitment to conserve 30% of Mexico’s marine territory.

Depending on the type of area-based conservation instrument implemented, such as the management categories of MPAs or the type of OECM, different ecological and socioeconomic benefits will be derived, contributing to the well-being of human communities that depend directly or indirectly on the good conservation status of the ecosystems and species present.

In general, the areas contributing to the management of fisheries will make it possible to improve catches in neighboring areas, linked to the recovery of fish stocks in no-fishing areas and the spill-over effect [74]. New economic alternatives can also be promoted in existing or newly created areas, either by changing the way a traditional activity is carried out (i.e., changing from harmful fishing gear to sustainable fishing alternatives) or by changing to other new activities (i.e., changing from fishing to eco-tourism) [75,76]. In addition, the creation of new areas can contribute to the creation of new jobs associated with conservation, restoration and ecotourism activities [77].

The benefits and effectiveness of well-managed MPAs in conserving ecosystems and marine species and addressing local threats have been widely demonstrated, bearing in mind that MPAs are old and consolidated area-based conservation measures [78]. The OECMs, on the other hand, have been recognized more recently, with their concept being presented, as mentioned above, in Decision 14/8 of COP 14 of the Convention on Biological Diversity in 2018 [11]. However, a recent study by Cook [79] shows that their development has so far been slow, with only a few cases where countries have started to identify other effective area-based conservation measures, and extremely rare cases where they have been assessed for their conservation effectiveness. This figure drops even further when it comes to the use of this tool in the marine environment. Studies of the marine OECMs identified by Cook [79] have been carried out in Canada [80], Mozambique [81], Italy and Israel [82] and the United Kingdom [83]. In Mexico, as in the rest of the world, the subject has received little attention in the literature. Fortunately, many international efforts are aimed at promoting the implementation of this new tool, which is expected to make a relevant contribution to the achievement of GBF Goal 3 [84].

The goals of increasing protected and conserved areas in Mexico through the various established area-based instruments cannot be separated from considerations of the effectiveness of these instruments. MPAs and OECMs must be proposed based on scientifically sound criteria and approved in a participatory manner that incorporates the views and needs of all stakeholders [85]. Once established, these areas must be managed effectively and equitably to conserve biodiversity and ensure the well-being of all people who depend, in one way or another, on the services provided by the ecosystems they protect [86].

More human and financial resources need to be mobilized to promote the effectiveness of area-based conservation instruments [87]. New funding alternatives, including those derived from resource user support, for payment for environmental services need to be explored [88] and new funding opportunities associated with the application of the GBF need to be exploited. Private initiatives, governments at different levels, academia and local communities need to work closely together to ensure participatory governance [89]. It is very important to ensure effective disclosure of threats, natural values, ecosystem services, management actions and projects implemented to raise public awareness of these issues [90].

Any area-based instrument that is created must be accompanied by rigorous monitoring of its effectiveness to ensure adaptive management that learns from past mistakes and successes [84,91]. Management effectiveness should be measured by evaluating the achievement of the conservation or management objectives for which it was created, but also by its contribution to sustainable development in its three dimensions: environmental, social and economic. Currently, this needs to be linked to the contribution of the areas to achieving the Sustainable Development Goals of the 2030 Agenda in its three main action lines: planet, people and prosperity [92].

It is very important to evaluate the progress or contribution of the sites in the ecological dimension, i.e., how the effectiveness of the conservation, restoration and management measures is reflected in the recovery of populations of threatened species or the improvement of the condition of ecosystems [93]. It should also be assessed whether the implementation of these sites has made their biological communities more resilient to climate change, or whether the carbon sequestration potential of the ecosystems is maintained or increased [94].

The impact of areas on human communities and stakeholders in the region (the social dimension) also needs to be assessed. This can be viewed from two perspectives: the impact of “areas on people” and the impact of “people on areas” [95]. For example, has access to resources been reduced? Have people been displaced as a result of the creation of areas? Have traditional activities of indigenous peoples or communities been restricted? Have illegal activities increased? Or, on the contrary, has the number of people benefiting increased? Has the availability of jobs increased? Positive effects of participatory management have been observed? and so on.

Regarding the economic dimension, in addition to the intrinsic link with the social dimension reflected in the economic spillovers to local communities, the environmental services provided by the ecosystems of these areas need to be regularly assessed [96]. Is the maintenance of ecosystem services and the well-being of human communities associated with these areas ensured?

Conservation and management measures must be based on the best available science [97]. Scientific assessments will provide an understanding of the changes taking place in marine and coastal areas in order to reverse deteriorating conditions. In this sense, during the Decade of Ocean Science for Sustainable Development, we will be able to take advantage of the interdisciplinary advances developed in marine sciences to achieve a better understanding of the ocean system [98]. Marine science will allow us to adequately address the negative impacts of climate change, marine pollution, loss of marine species and degradation of ecosystems.

Another important observation is the integration of the various area-based conservation measures (MPAs and OECMs) into broader plans of integrated coastal management or marine spatial planning, which ensure the conservation of biodiversity within schemes of sustainable development of associated human communities. This will support the provisions of Goal 1 of the GBF, which proposes that all areas adopt some form of integrated spatial planning that contributes to reducing threats to biodiversity [7].

The contribution of the protection and conservation of marine species and ecosystems to sustainable development through the creation of area-based conservation instruments is undeniable and has been widely recognized in many national and international strategies. Particularly noteworthy is SDG 14 “Life below Water” of the 2030 Agenda, which recognizes the need to conserve and sustainably use marine life as one of the main pathways to achieving sustainable development, with a specific target directed to increase the coverage of protected and conserved areas [99]. The GBF, with its vision for 2050 of “living in harmony with nature,” has proposed increasing the area of marine protected and conserved areas by up to 30% of the area under national jurisdiction as one of the main ways to ensure sustainable development, and also recognizes the strong link of this framework to the achievement of the 2030 Agenda for Sustainable Development and each of its goals [7].

The COVID-19 pandemic delayed the start of implementation of the GBF. In fact, it was only adopted at COP15 of the CBD in Montreal in December 2022, almost three years after the start of the decade. As a result, there have been few studies assessing the progress of its implementation. To date, most studies agree on the importance of achieving Target 3. Waldron et al. [100] showed that the current benefits of increasing area-based conservation measures by 30% far outweigh the economic benefits of not implementing them. However, many of the studies are also skeptical about the possibility of achieving Target 3. The latter is linked to the fact that, for example, none of the Aichi Targets has been fully met globally [88]. It is also linked to the current inability to address the global drivers of biodiversity loss [101]. It also highlights that the greatest investment needs are in some developing countries, as these are the most likely countries to face the greatest conservation challenges [102].

To achieve Target 3, the expansion and creation of new protected and conserved areas must be articulated with the proposals of the remaining GBF goals. To achieve this, biodiversity must be valued, conserved, restored and used wisely, maintaining ecosystem services, preserving a healthy planet and ensuring equitable and fair access to the benefits of nature. This major challenge to be met by 2030 requires an appropriate balance between the needs of people and users who depend on marine resources and their effective conservation. All actions must be integrated into existing coordination mechanisms at national, regional and global levels to optimize available resources and avoid duplication of efforts.