Clean water is vital for coral reefs and humans. Around the world, wastewater and polluted runoff cause severe damage to coral reefs, pose risks to human health, and threaten the tourism industry.

The Challenge
Honolua, Maui, Hawaii algae covering coral
Photo credit: Renee Capozzola

Land-based sources of pollution can easily—and often invisibly—harm coral reefs.

Directly discharged sewage and inadequately treated wastewater from cesspools and septic tanks carry high levels of nutrients, bacteria, chemicals, and pathogens into the marine environment. Activities like farming, logging, road construction, animal husbandry, and mining can produce pollutants such as sediments, fertilizers, and pesticides that run into the ocean when it rains.

An overabundance of either nutrients or sediment upsets coral reef ecosystems, promoting the growth of excess algae and bacteria and blocking the sunlight reefs need to survive.

Our Solution

We utilize science-based conservation strategies to ensure coral reefs have the clean water they need and to protect our coastal environments for people and wildlife:

  1. We scientifically monitor water quality to understand the nature of the problem (e.g., its source and magnitude) and identify solutions.
  2. We build and update sustainable wastewater treatment infrastructure by collaborating with governments and communities.
  3. We educate community members, local governments, and the tourism industry about the detrimental effects of poor water quality on human health, and coral reefs.
  4. We reduce sediment and nutrient delivery to coastal waters by motivating shoreline property owners to employ reef-friendly best practices.
  5. We restore and reforest streams and watersheds to create healthy landscapes that capture and stabilize nutrients and sediments before they reach the ocean.

Coral vs Seaweeds: Maintaining Balance
on Coral Reefs

Corals need clean, clear water to thrive. But what happens on a coral reef with overfishing and poor water quality?

Clean Water for Reefs in Puako, Hawai‘i

Clean Water for Reefs Puakō is a community-driven project that seeks to address wastewater pollution on the Puakō Reef on the north west Kohala coast of Hawaii Island. Wastewater pollution is found off the entire coast of Puakō and causes serious damage to corals, negatively affects marine wildlife and poses human health risks.


Wastewater Do’s and Don’ts

While this was designed for the residents of Puakō, Hawai’i, this infosheet is applicable to residents of or tourists visiting coastal communities where cesspools are in use around the world. Read through these best practices to make sure you’re doing your part to protect coral reefs.


Clean Water for Reefs Puakō Citizen Science Report

CORAL teamed up with The Nature Conservancy (TNC) and other experts to develop a monitoring plan designed to measure the impact of the wastewater infrastructure transition. Read the 2018 report water quality report to learn more about the program and its initial results.


Recycled Water For Reefs

This resource guide was developed to assist West Maui’s resort and condominium properties in transitioning to recycled water for irrigation.

Support CORAL

Our work to ensure clean water for reefs couldn’t happen without your support. Give today to help coral reefs survive.

Close flyout widget area

Help save the world’s coral reefs