The Survival Secrets of “Super Reefs”

Coral Reefs Are Essential but Declining Rapidly

Coral reefs have evolved over hundreds of millions of years, and most of the established shallow-water reefs around today are older than the Pyramids of Giza. A healthy reef is an incredibly complex ecosystem.

“Ironically,” says Aldo Croquer, a marine program manager for TNC who coordinates reef restoration in the Dominican Republic, “that complexity comes from simplicity, because if you see a coral, it’s the most simple thing that you could ever imagine.” Tiny, sack-like and tentacled organisms, each farming glucose from microscopic plants within it, build underwater fortresses that teem with life.

The reefs that cover less than 1% of the world’s surface area support 25% of all marine life. They draw tourists to enrich the economies of coastal communities. They provide protection from the full force of waves that could otherwise damage homes and erode shorelines. Over 1 billion people around the world rely on them for food, livelihoods and, in some cases, the very land upon which they farm and live.

Yet reefs are in dramatic decline. “Globally, we have already lost 50% of coral reefs,” says Dr. Elizabeth McLeod, TNC’s global reefs lead. “Some scientists predict that we could lose up to 90% by 2050 unless bold actions are taken to reduce climate change impacts and improve marine management.” 

Working Together in the Race to Save Reefs

Traditional reef conservation strategies are not enough in the face of climate change. An ecologically significant reef, shielded from overfishing and pollution in a carefully managed marine protected area, can still be devastated by ocean warming. A reef slated for demolition to make way for a new airport might actually be a heat-resistant super reef, whose billions of coral offspring could resettle degraded reefs if it were protected.

So a targeted, coordinated effort—like the joint super reefs partnership between TNC, WHOI and Stanford, with the participation of local conservation and government partners—is needed to locate and protect the world’s super reefs before they are lost.

“We don’t have a decade to get it right,” says McLeod. “And we need to be bringing our collective skills together. Time and funding are finite. This partnership allows us to prioritize our limited resources in the places that have the best chance of survival and support governments and communities leading the charge to save their reefs.”

First, the super reef partners engage community leaders, researchers, local groups and governments, building on TNC’s global network of coral reef projects to identify potential sites for reef conservation where there is local support and capacity.

Then, Dr. Cohen and the WHOI team develop meter-scale, three-dimensional, hydrodynamic models of reef temperature and flow to predict where super reefs might be. Using survey data model output, the team evaluates how corals in target areas responded to, and recovered from, prior heatwaves. Areas that experienced intense heat with higher survival rates are good candidates for heat tolerance evaluation.

This is where the work of Dr. Stephen Palumbi, a marine geneticist from Stanford University, and teams of local students and conservation leaders comes in. They test multiple species of corals for heat resistance, quantifying the corals’ ability to withstand heat and future heatwaves and generating crucial data for super reefs research.

The WHOI team then runs larval dispersal simulations to quantify connectivity between super reefs sites and other reef areas. Areas that exhibit both high heat tolerance and an ability to reseed neighboring reefs are prioritized for the next step. Dr. McLeod works with TNC colleagues and local partners to validate the model outputs with local data and support the protection and restoration of super reefs. 

Democratizing Science to Improve Research, Protection and Restoration

The key to reefs’ survival is not about a single, cure-all solution. “It is about the complex set of ecological conditions, human settings and situations that come together in the end,” says Palumbi. The science is one part of the story. The collaboration needed to expand its reach and put its conclusions into action is another.

A key feature of the super reefs project is the use of low-cost methods to identify heat-resistance in corals that can be replicated across multiple geographies, thus increasing the work’s pace and scale. Successful learnings can be rolled out through global knowledge-sharing networks, like the Reef Resilience Network initiated by TNC and NOAA’s Coral Reef Conservation Program, which connect marine practitioners around the world to the latest science and management approaches.

Ultimately, the best way to help reefs is to prevent their destruction in the first place. Reducing greenhouse gas emissions, improving the management of the world’s marine protected areas, and reef restoration are all important parts of the solution. The super reefs partnership improves reef conservation efforts by making them more effective under future, warmer conditions.

“Our mission is to save as much as possible, so that when the world gets better—and it will get better, because this is going to be solved—then there’s something to grow back from,” says Palumbi.