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Why is there so much broken coral on the beach lately?

Coral on the beach in Maui

Recently, many people have been asking  why there is so much broken coral on our usually smooth sandy beaches here in Maui.  The answer comes from a domino effect of ocean conditions that includes weather, water temperature, and waves.

Coral Bleaching

Perhaps you’ve read or heard about  coral bleaching in many parts of the world. Coral bleaching occurs when a small rise in water temperature stresses corals.  Recent coral bleaching is caused by an increase of water temperature triggered by El Niño.  The National Oceanic and Atmospheric Association has announced that we are in the third recorded global bleaching event since record taking began.

Coral bleach

According to Darla White, of the DLNR Divison of Aquatic Resources “When water temperatures rise, corals expel the zooxanthaellae, a symbiotic algae that lives in their tissues that gives them their color, leaving them either white or much lighter/brighter in color such as blue or yellow.  These algae provide up to 90% of their nutrition and energy from sugars produced during photosynthesis, so once they are expelled the corals have lost their primary food source and over time will weaken from starvation.”

Stressed coral

Though it happens in steps, the bleaching effects can be seen in a relatively quick period of time and can be seen all around the Hawaiian Islands.

Yellow coral

Without a doubt we are experience an epidemic of Coral bleaching.

Coral BleachingWhite also states “Corals can recover if the environmental conditions return to normal, but the stress from bleaching takes a huge toll on other energetic processes of growth and reproduction and leaves them vulnerable to disease.”

Coral Breakage

The corals that do not recover will be broken up by waves and large surf which will in turn  place them on the shoreline.

Waves move coralAlong with pieces of coral you may find sticks, coconuts or even shells on the beach.  Most shells  have been broken up by their rough journey through the waves and rocks to the sand as well.

coral rocks


Heart shaped coral

While you are out in the water snorkeling, please take pictures and report your findings to the Eyes of the Reef Hawaii.  Easy-to-follow instructions can be found on their website, but also here: Coral Reporting Instructions.

Coral Breakage

Also, keep in mind many people consider it bad luck to take rocks, coral or anything natural originating from the Hawaiian Islands.  (Remember that Brady Bunch episode?)  Consider leaving the coral right where it lays!

You can also help protect the reef by using a reef safe sunscreen, that does not contain  Oxybenzone.  Consider swimwear that already has sun protection built in.

heart arrow

Water temperatures are already cooling and we are staying hopeful that there will be a high recovery rate of the coral that has not already perished.

 If you have any questions about the coral or marine life, give us a call, or better yet, join our Hawaii Wildlife Fund certified naturalists aboard Kai Kanani 2.

For more things you can do, check these links out:

For more information on coral reef threats, great info here: