Coral Reefs: A Vision for the Future

This article was originally published by El Coquí of Rincón Magazine in June 2025 (pages 48-49).

For anyone who has ever snorkeled above a living coral reef, the experience is unforgettable. The kaleidoscope of colors, the darting schools of fish, the silent sway of sea fans in the current—it’s like entering another world. But for those of us who work in marine conservation, coral reefs are more than just beautiful; they are vital. They are living, breathing systems that support coastal communities, feed millions, protect shorelines, and harbor a quarter of all marine species.

Over the past decade and then some, we at Isla Mar have witnessed Puerto Rico’s reefs—especially the iconic Tres Palmas Marine Reserve in Rincón—face mounting challenges. Warming waters. New diseases. Bleaching events. And yet, we’ve also seen communities rise up to protect what they love.

This article is both a reflection and a call to action. It begins with the basics: what coral reefs are and how they form. It then tells the story of Tres Palmas—how it became a reserve, what threatens it today, and why it matters. And finally, it looks forward: to the ambitious, hopeful work we’re undertaking this summer through the Caribbean Reef Project, where we aim to add over 40,000 coral microfragments back onto the reef.

It’s a story of loss—but more importantly, of resilience, science, and community care.

What Are Coral Reefs?

Coral reefs are often called the "rainforests of the sea"—and for good reason. These vibrant underwater ecosystems are among the most biodiverse environments on Earth. Built primarily by reef-building corals, they support more than 25% of all marine life, even though they cover less than 1% of the ocean floor.

But what exactly is a coral?

Corals are animals, specifically they are marine invertebrates related to jellyfish and sea anemones. The reef-building corals most people are familiar with are colonial animals composed of thousands of tiny polyps, each secreting calcium carbonate to form a hard skeleton. Over time, these skeletons build upon one another, forming the complex and expansive structures we call coral reefs.

Reefs grow slowly, often just a few centimeters per year, but over centuries they can create structures that buffer coastlines and provide critical habitat for fish, crustaceans, mollusks, and countless other marine species. Corals rely on a delicate partnership with photosynthetic algae called zooxanthellae, which live within their tissues and provide the majority of their energy through sunlight. Spectacular and life-giving, yet easily disrupted by human interactions. We have also created some ways to help protect coral reefs from us, including the strategy known as marine protected areas (MPAs).

The Birth of Tres Palmas Marine Reserve

Along the western shore of Puerto Rico lies one of the island’s most iconic and ecologically significant marine areas: the Tres Palmas Marine Reserve. Located in our backyard of Rincón, this marine protected area was officially established in 2004 following grassroots efforts by local residents, scientists, surfers, and environmental organizations who recognized the urgent need to preserve the area’s fragile coral ecosystems.

Tres Palmas was once home to one of the healthiest remaining stands of Acropora palmata, or elkhorn coral, a species once abundant across the Caribbean but now listed as threatened. The reef’s clear waters, consistent swell, and rich biodiversity also make it a draw for recreational snorkeling, surfing, and scientific research. The designation of the reserve not only protected the reef from further degradation, but it also served as a model for community-driven conservation in Puerto Rico.

Mounting Threats to Coral Reefs

Despite their ecological importance and cultural value, coral reefs around the world are under siege. Climate change, pollution, overfishing, and habitat destruction are placing unprecedented pressure on reef systems—and the reefs at Tres Palmas are no exception.

In recent years, two major threats have taken center stage in Puerto Rico and the wider Caribbean:

Stony Coral Tissue Loss Disease (SCTLD)

A few years ago, a new and deadly threat emerged in the form of Stony Coral Tissue Loss Disease (SCTLD), a fast-spreading illness first observed off the Florida coast in 2014. This bacterial disease affects over 20 species of hard corals, including many of the foundational species that build reef structure.

SCTLD reached Puerto Rico’s reefs in 2019 and has since swept through various parts of the island, leaving behind patches of dead and degraded reef. Its arrival at Tres Palmas a couple years later prompted rapid response efforts and further emphasized the need for resilience-focused reef restoration strategies.

Coral Bleaching

Even more recently, coral bleaching has taken a toll on the remaining, surviving corals in the reserve. Bleaching occurs when elevated ocean temperatures disrupt the symbiotic relationship between corals and their algae. When stressed, corals expel the algae, losing their color and their primary source of energy production. If high temperatures persist, the corals can die.

Tres Palmas experienced significant bleaching events during the last two summer/fall seasons. These episodes affected large swaths of coral, particularly the more sensitive branching species, and served as stark reminders of how even protected areas are vulnerable to global climate patterns.

A Vision of Hope: The Caribbean Reef Project

In the face of these challenges, hope lies in action—and that action is now underway.

This summer, as part of the Caribbean Reef Project, we will begin planting 40,000 coral microfragments at Tres Palmas Marine Reserve. Using state-of-the-art coral propagation techniques, scientists are growing small corals in land-based nurseries in La Parguera and Ceiba before carefully outplanting them to the reef. These microfragments—each just a few centimeters across—grow faster than whole colonies and have a higher chance of survival when planted in dense clusters.

This effort represents one of the largest coral restoration initiatives ever attempted in Puerto Rico, and it reflects a powerful coalition of local scientists, community leaders, NGOs, and international supporters.

The project also goes beyond planting corals. In fact, it’s more about habitat restoration overall. Led by the Institute for Socio-Ecological Research (ISER Caribe) and composed of numerous scientific organizations including Rincon’s own Isla Mar, the Caribbean Reef Project will also release herbivores – like sea urchins and crabs – to these restored coral reefs. Armed with allies to combat algal overgrowth, the outplanted corals and those still existing naturally on the reef will have a greater chance of survival with the help of these algae-eating animals by their side. Besides this, the project will also involve:

• Monitoring to track coral health, survival rates, and biodiversity changes.

• Community engagement to train volunteers, educate visitors, and empower local residents to become reef stewards.

• Adaptive management to evolve techniques based on real-time feedback from the field, including using high-resolution photography to observe coral growth in an “aerial” underwater view.

By restoring key coral species and increasing the genetic diversity of the reef, the Caribbean Reef Project aims not only to rebuild coral cover but also to strengthen the reef’s ability to withstand future stressors.

A Reef Worth Saving

Tres Palmas Marine Reserve is more than a beautiful snorkeling site—it’s a living classroom, a cultural touchstone, and a symbol of what's possible when communities come together to protect what they love.

As the threats facing coral reefs grow more intense, so too must our commitment to their protection and restoration. Through science, collaboration, and sustained care, we can give reefs like those at Tres Palmas a fighting chance.

And perhaps, decades from now, snorkelers and scientists alike will swim among thriving coral colonies that were planted by our hands, rooted in our shared vision for a better, bluer future.