At the Coral Reef Alliance (CORAL), we believe healthy coral reefs start on land. Our work on water quality across the Mesoamerican Reef (MAR) region—spanning Belize, Honduras, and Mexico—shows how science, community collaboration, and practical solutions can protect these ecosystems and the communities that rely on them.
Why Water Quality Matters for Coral Reefs
Clean water is vital for coral reef health.
Poor water quality fuels algae blooms, smothers corals, and increases disease, threatening the biodiversity and resilience of these ecosystems. Learn more about why water quality is so important for coral reefs >
Across the MAR, reefs are particularly vulnerable to pollution from untreated sewage, agricultural runoff, and tourism development. Our Regional Water Quality Monitoring Project, which collected data at 90 sites across Belize, Honduras, and Mexico, revealed alarming levels of turbidity, pathogens, nitrogen, and phosphorus—all of which can stress or kill coral reefs.
The good news? Now we know. And we can do something about it.
Collecting Data for Action
At CORAL, we gather solid data for meaningful action.
Our regional water quality work began with a protocol that ensured a coordinated study to pinpoint the major sources of pollution and identify priority areas for intervention. Here’s what we found:
The entire Mesoamerican Reef is impacted by high levels of nutrients, particularly ammonia, and these contaminants are found on the reef.
Honduras
30 sites revealed high nitrogen and pathogen levels, particularly around tourism hubs in the Bay Islands and sites close to river outflows from the mainland.
Belize
30 sites showed elevated turbidity, phosphorus, and pathogens.
Mexico
30 sites highlighted elevated ammonia and phosphorus.
Pollution sources for the region come from untreated sewage, poor update and management of septic tanks, urban runoff, and unsustainable agricultural practices.
What does this mean for the reef?
When pollution enters the ocean, it can fuel algae growth, smother coral, disrupt the delicate balance of reef ecosystems, and spread harmful pathogens that make corals more vulnerable to disease. Nutrient-rich runoff and untreated sewage can also cloud the water, blocking sunlight that corals need to thrive.
Over time, these impacts can reduce biodiversity, weaken reef resilience to climate change, and harm the communities that depend on healthy reefs for food, tourism, and coastal protection. Learn about other water quality issues plaguing coral reefs today >
What We’re Doing
It’s time for collective action to spark global changes.
Based on these findings, we’re working with local water associations, governments, and partners across the MAR to put real solutions in place. These actions are tailored to the unique challenges of each country and are designed to drive meaningful change.
Here’s what we’re doing to tackle water quality challenges head-on:
Investing in Wastewater Treatment
Advocating for infrastructure and governance investment that leads to improved sewage treatment infrastructure in tourism-heavy areas and urban centers, especially in Cozumel, Belize, and Honduras.
Community-Led Water Management
Strengthening local water associations—like the West End Polo’s Water Association in Honduras— and water and sanitation service providers across the region to manage water and sanitation sustainably.
Integrating Water Quality in Protected Area Management
Ensuring water quality standards are included in marine protected area management plans throughout the MAR.
Expanding Monitoring and Enforcement
Collaborating with local partners to build robust water quality monitoring and compliance systems to track improvements and guide action.
Our Recommendations
These recommendations are rooted in science, community collaboration, and a commitment to solutions that last. They’re designed to guide governments, communities, and private sector partners in taking meaningful action.
Upgrade and Expand Wastewater Infrastructure
Prioritize sewage treatment in high-tourism zones and urban centers in Belize, Honduras, and Mexico.
Strengthen Land-Use and Agricultural Policies
Develop land-use plans that consider water quality and quantity impacts, and promote sustainable agriculture to reduce runoff.
Modernize and Enforce Regulations
Invest in strengthening technical skills, update and enforce regulations to control discharges, and include water quality standards in protected area management plans, aligning with international standards.
Raise Awareness
Support education actions to engage communities and tourists in protecting water quality and reef health.
Secure Funding for Solutions
Advocate for funding from governments, donors, and the private sector to invest in sustainable water quality management.
Together, these actions can drive real progress—reducing pollution at the source, strengthening community resilience, and ensuring coral reefs remain a vibrant, life-sustaining resource for generations to come. By working collaboratively across the MAR, we can build a cleaner, healthier future for reefs and people alike.
Dive Deeper into the Policy Briefs
Want to explore the details? Read our policy briefs for Belize, Honduras, and Mexico.
📎 Download the Belize Policy Brief
📎 Download the Honduras Policy Brief
📎 Download the Mexico Policy Brief
The Power of Partnership
We know lasting change is built on collaboration.
That’s why our water quality efforts in the MAR region are rooted in partnership, trust, and the power of collective action. By working side by side with communities, governments, scientists, and tourism leaders, we’re transforming data into solutions that protect both coral reefs and the people who depend on them.
This work is more than a project—it’s an alliance. An alliance that unites local knowledge with global expertise and puts communities in the driver’s seat. This makes progress possible. All for the future of coral reefs.
We believe that everyone has a role to play in protecting coral reefs. Whether you’re a policymaker, a scientist, a business owner, or a visitor to these remarkable places, you are part of the solution. Join us in this alliance for clean water and healthy reefs. Together, we can turn the tide for the Mesoamerican Reef—and for our shared future.
Let’s build a cleaner, healthier world—together.
