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On Wildlife Conservation Day, Protect Climate Refuges to Help Corals

By Emily Darling

This year Wildlife Conservation Day, December 4, arrives as we have just completed the once-a-decade World Parks Congress. Thousands of representatives from the global conservation community – from academics and NGO staff to policy makers and agency representatives – gathered in Sydney, Australia to discuss how we may better protect and preserve critical protected areas for nature across the globe, both on land and in the sea.

Protected areas are a hallmark strategy in marine conservation. Yet when they were first created, a growing lethal threat had not yet fully revealed itself. Warming, acidifying, and rising seas have devastated the world’s sensitive coral reefs, widely regarded as “ground zero” for climate change. El Niños and marine heat waves can bleach and destroy vast areas of healthy, biodiverse reefs even where they occur within “protected” parks.

Scientists from the Wildlife Conservation Society survey coral communities to assess the impacts of climate change and identify climate refuges where coral diversity can escape marine heatwaves and survive into the future. Photo credit: Emily Darling ©WCS.
Scientists from WCS (Wildlife Conservation Society) survey coral communities to assess the impacts of climate change and identify climate refuges where coral diversity can escape marine heatwaves and survive into the future. Photo credit: Emily Darling ©WCS.

If the global impacts of climate change do not stop at park boundaries, what can scientists do? One strategy is to identify and protect climate refuges – habitats with more stable environments where species can survive warming temperatures.

Kenya, for instance, has some of the oldest and most effective no-take marine reserves in the Western Indian Ocean with more diverse corals and healthy fish populations. In 1998, an El Niño heat wave provoked the warmest ocean temperatures ever recorded, killing nearly half of living corals in the Western Indian Ocean.

El Niños and ocean heatwaves create superheated sea temperatures that bleach and kill living corals. Even corals protected within no-take marine reserves are susceptible to mass coral bleaching, which emphasizes the important role of climate refuges in protecting coral diversity. Photo credit: Emily Darling ©WCS.
El Niños and ocean heatwaves create superheated sea temperatures that bleach and kill living corals. Even corals protected within no-take marine reserves are susceptible to mass coral bleaching, which emphasizes the important role of climate refuges in protecting coral diversity. Photo credit: Emily Darling ©WCS.

WCS (Wildlife Conservation Society) scientists were surprised to find that coral communities protected within marine reserves were more harmed by bleaching than were adjacent unprotected and fished reefs.

Why? Twenty years of monitoring data collected by WCS revealed that unprotected, fished reefs had tougher corals capable of surviving the marine heat wave. Reserves, on the other hand, had provided a safe harbor for sensitive branching and plating corals that were highly sensitive to death by bleaching – leading many to believe that species diversity may be the Achilles heel of protected areas in the face of climate change.

Tougher species such as massive brain corals can survive El Niños and marine heatwaves that can bleach and devastate healthy coral reefs. Photo credit: Emily Darling ©WCS.
Tougher species such as massive brain corals can survive El Niños and marine heatwaves that can bleach and devastate healthy coral reefs. Photo credit: Emily Darling ©WCS.

If you travel about 900 miles south from Kenya to the Quirimbas archipelago of the northern Mozambique channel, there is a very different story to tell. Diving into the crystal waters off Vamizi Island, there are fields of healthy branching and plating corals – the species that disappeared and have not recovered after the marine heatwave in Kenya.

Vamizi’s reefs escaped the marine heat wave hidden from superheated waters in the shadow of Madagascar, where a series of oceanic gyres circulate cool water. Vamizi’s corals did not catastrophically bleach in 1998 and remain intact today – a rare example of biodiversity in the Western Indian Ocean. To help coral reefs adapt to climate change, we need to strategically identify and protect these and other such climate refuges.

Coral reefs off Vamizi island in the northern Mozambique channel escaped the 1998 marine heat wave and mass bleaching event cooled by ocean gyres in the shadow of Madagascar. Today, these reefs are the gems of the Western Indian Ocean and require management in the face of overfishing, land-based stressors and oil and gas developments. Photo credit: Emily Darling ©WCS.
Coral reefs off Vamizi island in the northern Mozambique channel escaped the 1998 marine heat wave and mass bleaching event cooled by ocean gyres in the shadow of Madagascar. Today, these reefs are the gems of the Western Indian Ocean and require management in the face of overfishing, land-based stressors, and oil and gas developments. Photo credit: Emily Darling ©WCS.

More refuges might be found in other marine ecosystems that offer a natural advantage. Examples include Raja Ampat in Indonesia and the sheltered shallow lagoons of the Republic of Palau. These climate refuges that promote escape or adaptation may be our best hope for protected areas to buy time for species to adapt and to sustain healthy coral reefs into the future.

To facilitate the development of more climate-smart marine protected areas, we must not only identify climate refuges but we will need to catalyze local communities, national governments, and multilateral agencies to protect them.

Coral reefs support local livelihoods and food security through fisheries and coastal protection from storms. Here, women fish traders dance as the day’s catch is landed. Photo credit: Emily Darling ©WCS.
Coral reefs support local livelihoods and food security through fisheries and coastal protection from storms. Here, women fish traders dance as the day’s catch is landed. Photo credit: Emily Darling ©WCS.

On World Conservation Day, let’s commit ourselves to coordinating, funding, and implementing a global plan to link climate refuges within networks of protected areas for all ecosystems: coral reefs, tropical rainforests, Arctic tundra and beyond. It is my hope that by the next World Parks Congress, we will have made courageous commitments and measurable progress in giving corals and other sensitive species a fighting chance at survival as our world continues to heat up.

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Emily Darling is a research associate with the Wildlife Conservation Society, where she coordinates a new global monitoring initiative for coral reef fisheries. She is also a David H. Smith Conservation Research Follow at the University of North Carolina at Chapel Hill, where she investigates climate change on coral reefs.