Welcome to Maui’s Unique and Remarkable Undersea World
We invite you to explore Maui’s coral reefs – with care and respect, for your safety and the protection of these diverse and beautiful marine ecosystems.
As you snorkel or dive here, youʻll encounter rare and unique marine life. Because Hawaiʻi is surrounded by thousands of miles of ocean, the species that found their way here evolved in isolation. As a result, about 25% of our corals, fish and marine algae are endemic, found nowhere else on earth.
Coral reefs are valuable for many reasons: in addition to their beauty and diversity of life, they support about 25 percent of Hawaiiʻs marine life. Corals also protect our shorelines and beaches from storm surges, big waves, erosion and storms. Unfortunately, coral reefs are among the most threatened ecosystems on the planet due to climate change, warming oceans, ocean acidification and pollution. Help our reefs survive by taking care when you snorkel, swim, dive, paddle or surf near coral.
Corals are Living Animals
Coral reefs may look like rock but they are actually living animals. Coral reefs are formed by compact colonies of tiny soft-bodied animals known as coral polyps. Coral polyps have tiny tentacle-like arms that extend to sweep food into their mouths. Each polyp secretes a hard outer skeleton of limestone (calcium carbonate) that either attaches to rock or to the dead skeletons of other coral polyps. Over time, these limestone skeletons build up and create the hard structure of the reef. Some of Hawaiiʻs local coral reefs are hundreds of years old.
Take Care Around Corals
Please remember that the coral polyps are delicate. Each polyp is no thicker than a nickel, and they can be crushed and killed when you stand or walk upon them. Once a polyp dies, it can no longer build the reef. If the entire colony perishes, the reef structure breaks down and disappears.
- If you must stand, do so only on sand.
- Keep your fins up — a flotation device helps. - Avoid standing, walking upon or kicking coral.
- Never touch corals. They are sharp and can cut you. - Viruses, bacteria and stinging cells living within the corals can also cause serious infections. If you are cut by coral, leave the water immediately and care for your wound. Click here to learn how to treat coral cuts.
Coral Bleaching Threatens our Reefs
Most corals obtain energy from beneficial algae called zooxanthellae (pronounced zo-UH-zan-thuh-lay) that live within their bodies. The algae produce energy from sunlight; this energy helps nourish the corals. The algae also give corals their color.
Corals can become stressed by warming ocean water, too much freshwater, sedimentation or pollution. When this stress occurs, the beneficial algae leave the coral tissues. This causes the corals to turn white, which is known as coral bleaching. Corals can survive without the algae (and the energy it produces) temporarily, but eventually, the corals die.
Ocean warming caused by climate change has caused significant coral bleaching and coral deaths in Hawaiʻi.
- Be an advocate for the reefs. Speak out and help fight climate change.
- Reduce your use of household and landscape chemicals.
- Support programs that protect ocean water quality and prevent sediment runoff into the sea.
Does Your Sunscreen Harm Corals?
Researchers have found that common sunscreen chemicals can harm or kill corals, even in small concentrations. Hawaiiʻs sunscreen law, which bans products containing reef-harming oxybenzone and octinoxate, goes into effect on January 1, 2021, but why wait? Get a jump on protecting our local coral reefs by making the sunscreen switch today.
- Avoid sunscreen and body care products containing oxybenzone and octinoxate.
- Choose zinc or titanium-dioxide based products instead.
- Skip spray-on products which leave residues on the sand that can get washed into the ocean.
- Reduce your need for sunscreen by covering up with a rash guard, hat, umbrella or swim tights.
- Get more info about reef-safe sunscreen choices. Click here.
It’s easy to make the switch to safer-for-the-reef alternatives. Check out our short video.
Learn More About Hawaii’s Coral Reefs
The most common corals found in Hawaii’s nearshore reefs are Porites (smooth coral), Montipora (rice coral) and Pocillopora (small branching coral). Visit Eyes on the Reef – Hawaii to learn to identify our local coral reef species.
Hawaii’s Reef Fish
Hawaii’s Sea Turtles
The most commonly sighted sea turtle in Hawaiʻi is the green turtle, a species listed as threatened under federal and state law. Youʻll find green turtles swimming among our nearshore coral reefs or basking on shore at some of our island beaches. Hawksbill turtles are also found here, but sightings are infrequent. Hawksbill turtles are listed as endangered. It is illegal to harm, harass or kill these marine reptiles.
- Always give turtles at least 10 feet or more of space. - Never touch or attempt to feed sea turtles.
- Call (888) 256-9840 to report stranded, injured or entangled sea turtles.
Hawaii’s Monk Seals
Itʻs a special treat to see a Hawaiian monk seal. There are critically endangered, with only about 1,200 of these seals alive today.
- If you see a monk seal in the water, exit the water immediately for your safety.
- Hawaiian monk seals also haul out on our beaches to rest, give birth and care for their pups. Keep your distance and also keep your pets away. Stay behind any signs or barriers.
- Use the “rule of thumb” to determine a safe distance (if no signs or barriers are present)
◦ Make a “thumbs up” gesture and extend your arm straight in from of you.
◦ Turn your thumb parallel to the ground in your line of sight of the seal.
◦ If your thumb covers the entire seal, you are far enough away (about 50 feet or 15 meters).
- Learn more about viewing monk seals, dolphins and whales of Hawaiʻi.
- Call (888) 256-9840 to report stranded, injured or entangled monk seals, dolphins and whales.