The ocean is changing faster than at any point in human history. By 2100, as much as 90% of marine life may face a high or critical risk of extinction from warming, acidification, and deoxygenation. For Nigeria, where rising sea levels threaten to submerge up to 18,000 square kilometers of coastal land, the stakes are immediate.
In this crisis, scientists are focusing not just on what we will lose, but on where life can survive. These places are called marine climate refugia.
What exactly is a marine climate refugia?
A marine climate refugia is a natural area in the ocean that remains relatively stable – cooler, less acidic, or otherwise buffered – while the waters around it change dramatically due to climate change.
The U.S. Geological Survey defines them simply as places “that will be protected from climate change, at least relative to the land around them”. They are not immune to warming, but they change much slower.
Think of them as ocean “safe havens”:
- Thermal refugia: areas with cool-water upwelling, like parts of the Great Barrier Reef that may stay over 1°C cooler than surrounding waters into the 2080s
- Acidification refugia: coastal seagrass beds and kelp forests that locally raise pH through photosynthesis
- Deep-water refugia: mesophotic reefs (30-150m deep) and canyons shielded from surface heatwaves
- Hydrodynamic refugia: zones with strong currents or mixing that prevent prolonged heat stress
Historically, refugia like the Amazon and Congo Basin saved species during ice ages. Today, the ocean needs the same strategy.
Why do marine climate refugia matter? 5 critical reasons
1. They are biodiversity arks
Refugia act as short-term sanctuaries and long-term genetic reservoirs. When managed well, they allow species to persist, reproduce, and later re-seed damaged areas.
2. They buy time for adaptation
Corals, fish, and plankton in refugia experience less frequent bleaching and mortality. This extra time is crucial for natural adaptation and for humans to cut emissions.
3. They make conservation smarter
A 2025 global study in Nature Communications identified 17.6 million km² of marine climate refugia using a conservative approach. Critically, 96% of these are inside countries’ Exclusive Economic Zones (EEZs), meaning national action can protect them.
Yet 70% of these refugia currently lack any protection, representing a conservation gap of over 12.3 million km². Closing that gap would help the world reach the “30 by 30” target to protect 30% of the ocean by 2030.
4. They protect livelihoods
In Nigeria, The Nigerian Marine Environment Protection Association (NIMEPA) combats threats through prevention, community engagement, and policy integration to protect marine life and food security. Protecting refugia directly supports fisheries, because stable spawning grounds mean more fish for coastal communities.
5. They strengthen coastal defense
Nigeria’s coral reefs and mangroves already protect shorelines from erosion and storm surges. Climate-stable mangrove refugia in the Niger Delta and Cross River estuary will be vital as sea levels rise.
Where are marine climate refugia in the Gulf of Guinea?
While global mapping is new, West Africa has key candidates NIMEPA is monitoring:
- Upwelling zones off Ghana to western Nigeria: Seasonal cold-water upwelling creates thermal relief during marine heatwaves, which have become persistent since 2015
- Deep canyons off the Niger Delta: Provide stable temperatures and shelter for deep-water species
- Mangrove-seagrass mosaics in Lagos, Ondo, and Bayelsa: These act as local acidification buffers
- Offshore cold seeps and mesophotic reefs: Less studied but potentially critical for Nigeria’s blue economy
Nigeria faces a unique vulnerability. The Gulf of Guinea is warming, and stable conditions in Nigeria also favor accumulation of pollutants like microplastics, increasing stress on species. This makes identifying and cleaning refugia doubly important.
What NIMEPA is doing about it
NIMEPA’s mandate aligns directly with refugia protection:
- Mapping and Research: Partnering with universities to identify thermal and chemical refugia in Nigeria’s EEZ
- Community-led Protection: As seen in our Atican Beach cleanup, we emphasize shared environmental responsibility to reduce local stressors in potential refugia
- Policy Advocacy: Pushing for refugia to be prioritized in Nigeria’s Marine Protected Area network and Blue Economy strategy, integrating sustainable marine operations
- Restoration: Leading coral and mangrove restoration because healthy habitats are more likely to become refugia
How you can help protect ocean refugia
- For government: Designate at least 30% of Nigeria’s EEZ as MPAs, prioritizing climate-stable zones identified by science
- For industry: Adopt the seven marine environment protection systems NIMEPA promotes on ships – from oily water separators to ballast water treatment – to reduce local pressures
- For communities: Protect mangroves, stop dynamite fishing, and report pollution. Local stress reduction is what turns a stable area into a true refugia
- For researchers: Share data on temperature, pH, and biodiversity to refine Nigeria’s refugia map
The bottom line
Marine climate refugia are not a substitute for cutting emissions, but they are the foundation for ocean survival. As the 2025 global study concludes, they represent “the last hope for marine life amid impending global changes”.
For Nigeria, protecting these climate-stable pockets in the Gulf of Guinea is about more than biodiversity. It is about food security, coastal protection, jobs in the blue economy, and cultural heritage.
NIMEPA believes that by identifying, managing, and conserving refugia now, we give the ocean – and ourselves – a fighting chance.
Want to get involved? Join NIMEPA’s membership network for individuals, corporates, and affiliates working on marine protection in Nigeria. Visit nimepa.org to learn about our next coastal resilience workshop.
