Making the first ever official assessment of the conservation status of mangrove ecosystems in the Galapagos Islands, scientists from the Charles Darwin Foundation have declared the region ‘vulnerable’ in accordance with the Red List of Ecosystems methodology as developed by the International Union for Conservation of Nature. 

The evaluation has been made as part of a wider study into the health of mangroves across the globe which, based on assessments made by more than 250 scientists from 44 countries, concluded that more than 50% of the world’s mangroves are now at risk of collapse.

Mangrove ecosystems play essential roles in maintaining biodiversity, mitigating climate change, and protecting coastlines against natural disasters. Their conservation status around the globe, however, is precarious.

While mangroves currently cover approximately 150,000 square kilometres worldwide (primarily along tropical and subtropical coastlines), their ecosystems face major threats including deforestation, aquaculture, climate change, and rising sea levels.

Scientists from the Charles Darwin Foundation have now warned that without “urgent conservation actions”, these critical ecosystems could face significant degradation by 2050, with “potentially severe ecological, social, and economic impacts.”

Galapagos mangroves, in particular, is one of just 36 ‘ecoregions’ identified by the International Union for Conservation of Nature (IUCN). covering 36.6 square kilometres, they account for just 0.03% of the global mangrove area. But despite their size, they provide vital ecosystems and habitats for numerous native and endemic species, serving as essential areas for living, feeding, reproducing, and sheltering from predators. 

In fact, Galapagos mangroves support at least 70 species on the IUCN Red List of Threatened Species, including sharks, rays, sea turtles, Galapagos penguins, and flightless cormorants. They are also home to the last remaining population of the critically endangered mangrove finch – a bird estimated at only 100 individuals with fewer than 20 breeding pairs.

“Although they represent just a small fraction of the global mangrove area, Galapagos mangroves hold immense value as vital habitats for countless endangered species,” said Nicolas Moity, lead author of the assessment and principal investigator at the Charles Darwin Foundation.

In the Galapagos Islands, nearly all mangrove areas are situated within the Galapagos Marine Reserve, an area in which destructive activities like shrimp aquaculture – a practice responsible for a 40% loss of mangroves on mainland Ecuador over the past 40 years – are strictly prohibited. 

The report issued this week is the first comprehensive evaluation of the threats faced by Galapagos mangroves, conducted with the participation of scientists from the Charles Darwin Foundation, IUCN specialists, and the Smithsonian Institution.

It actually subverts common belief that Galapagos mangroves – owing to their protected status – faced few threats. Applying the IUCN Red List of Ecosystems methodology, however, revealed that Galapagos mangroves are classified as ‘vulnerable’. Major threats identified in the study include volcanic eruptions, tsunamis, fires, and invasive species.

In 2018, the Sierra Negra volcanic eruption resulted in the loss of approximately 18 hectares of mangroves in western Isabela. Similarly, in 2011 a tsunami left a trail of dead mangroves along the coastline, affecting over 250 hectares of the precious ecosystem.

When natural events such as these – which occur approximately every two years in the Galapagos – are compounded by human-induced impacts such as pollution, fires, plastics, microplastics, hydrocarbons, boat damage, and urban expansion, the ecosystem’s considerable vulnerabilities are exposed.

“Establishing permanent monitoring sites on the islands, particularly in places like Isabela, is essential to better inform conservation and management measures,” said Moity. “Following recent volcanic eruptions, we lack crucial information, such as which mangroves species were lost, the amount of carbon these ecosystems stored, and the species that depended on them.

“These data are vital for assessing the real impact of such disasters and developing effective mitigation measures.”

Pilot studies led by Moity indicate that Galapagos mangroves have the potential to store 1.8 million tonnes of blue carbon, significantly contributing to climate change mitigation. However, future changes in precipitation patterns, sea temperature, ocean currents, and winds could each significantly alter the growth and health of mangroves.

Under a projected sea level rise of 1.1 metres by 2060, up to 25% of the current Galapagos mangroves could be submerged. This would not only compromise their blue carbon storage capacity but also threaten the survival of numerous species that rely on them.

“Identifying key mangrove areas that store the most carbon, host the greatest biodiversity, and provide the most ecosystem services is a top priority,” said Moity. “Because different species depend on mangroves in varying ways, and mangrove development is highly variable, understanding which areas deliver the highest ecological function and ecosystem services will guide conservation efforts more effectively and with greater precision.”

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