Why is it Green Listed?

The biosphere reserve Island San Pedro Martir has great scientific relevance for what is considered a natural laboratory of adaptation and evolution. It is one of the best preserved sites of the Gulf of California. This marine protected area has a great biological wealth, registering 292 species of flora and fauna both marine and terrestrial, of which 42 species are protected, either by the Mexican laws (NOM ECOL-059 2001) 30 in the IUCN Red List and 36 under CITES. This island is home to the world´s largest nesting colonies of blue-footed boobies (Sula nebouxii) and brown boobies (S. leucogaster), one of the largest colonies in Mexico of brown pelicans and probably the largest colony in the Gulf of California of the red billed tropic bird (Phaethon aethereus). It also houses the fourth most important breeding colony of sea lions (Zalophus californianus) of the Gulf of California. In its surrounding waters there are 14 species of marine mammals, big aggregations of whales (Physeter macrocephalus) are often seen in its western portion. In its insular habitat there are two species of endemic reptiles: the lizard whiptail (Aspidoscelis martyris) and stained sides lizard (Uta palmeri); while the Emperor black snake (Lampropeltis nigritus) is restricted to just a few islands in the Gulf. The fishing bat (Myotis vivesi), which is endemic to the Gulf of California, also lives on this island. Currently the island is free of exotic species, due to an eradication program in 2007. Black rats (Rattus rattus) were introduced to the island during the extraction of guano in the nineteenth century. The top of the island is covered by a forest of columnar cacti, considered the best-preserved portions of the Sonoran Desert. In the waters of this reserve there are five types of marine habitats: black coral beds (Antiphates galapagensis), rodolith beds which sustain rich diversity of fish and invertebrate species (some of them commercially important). There are also Sargassum forests, sandy habitat, and a wide rocky habitat that houses a big number of species. The reserve has an economic importance, and its main users are artisanal fishers who come from at least 5 communities in the Gulf of California, as well as foreign anglers with permits. To a lesser extent the island is visited for tours and researchers. 

Key Achievements

Conservation

• From 15 years of monitoring data on the coastal rocky reef, it has been observed that the total observed biomass has increased in the reserve from 9.2 kg/100m2 in 2007 to 19kg/100m2 in 2022. Over these 15 years, changes have been observed in the average size of some of these fish species that are resources for fisheries, such as sardine grunts, the average size increased from 21.86 cm in 2007 to 37.17 cm in 2021. 
• Since 2011, the monitoring of the California sea lion breeding colony has been carried out annually, following a standardised protocol. Different studies carried out on sea lions in the Gulf of California suggest that changes in sea lion population numbers, and in particular pup production, depend on anomalies in sea surface temperature, which is related to primary productivity and therefore to the availability of food. The period from 2014 to 2016 was very unfavourable for the sea lion population due to two major events, “El Niño” and “The Blob”. Between 2017 and 2023, annual monitoring data indicate a population growth trend in the colony of 103%, from 1192 individuals to 2395. Likewise, a growth trend in pup production of 134%, from 234 pups present in 2017 to 549 in 2023. 
• The eradication of the black rat (Rattus rattus) was conducted in the summer of 2007. Since then, education activities have been conducted with fishermen to promote on practices that prevent the reintroduction of this species. The Biosphere Reserve, with the support of organized groups from the community of Bahía de Kino, previously trained, has carried out monitoring to confirm the absence of the exotic rodent on the island. As a result of the monitoring effort from 2008 to 2023, it has been verified that the San Pedro Martir Island Biosphere Reserve is still free of rats. 

Good governance

• The Advisory Council (AC) was first evaluated in 2021 across 32 criteria, 46.9% good, 37.58% fair, 3.12% poor and 12.5% undetermined. Subsequent to the assessment, the AC made changes that helped to improve several of the criteria in Fair status. The Advisory Council has representation from relevant sectors: fisheries, academic institutions, non-governmental organizations and government institutions (local, state and federal). The strengthening and improved operation of the AC was achieved in several aspects: the updating of its internal regulations, greater participation of the sectors and the representation of women members increased from 7.69% in 2017 to 46.15% in 2023. The Youths and the Scientific sub-councils were formed to promote inclusion. During 2022 and 2023 the Advisory Council actively participated in the revision of the Management Plan. 
• A group of community promotors are doing a great job in environmental education and social marketing campaigns. Currently, artisanal fishermen consider that as a result of the coordinated work with the Directorate of the RB San Pedro Martir Island, there is greater respect for the resources, greater knowledge about the environment, laws, rules and regulations related to fishing and the environment. They affirmed that many fish species are more abundant now than they were 10 years ago. 76% consider that the current state of the RB Isla San Pedro Martir is the same or better than ten years ago. 
• Fishermen from Bahía Kino and their families, through groups of trained environmental promoters, carry out monitoring, surveillance and citizen science activities, and are actively participating in the conservation of the protected area and contributing information for decision-making. 

Community benefits

• The proportion of local fishermen and their families who support the existence of a core zone (where fishing is not permitted) in the San Pedro Mártir Island Biosphere Reserve increased from 69% in 2012 to 90.2% in 2023. The Core Zone is a tool that facilitates the restoration of rocky reef fish populations. Results of the monitoring carried out in the Reserve indicate that since its creation in 2002, the biomass and sizes of some commercial fish species have increased throughout the Reserve, which is a benefit for fishermen and their community.
• With subsidy programmes, the fishing community and users of the Isla San Pedro Mártir RB receive direct benefits for themselves and their families, and the Biosphere Reserve benefits from the work of monitoring, community surveillance, ecosystem restoration and environmental education. Sustainable productive projects, capacity building and exchanges of experiences with other communities have been promoted. Through workshops on socio-environmental diagnoses with a gender perspective, men and women from the community of Bahía Kino expressed their problems, which are taken into account in the development of the strategic plan for the protected natural area and the development of actions for its conservation.