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CRITTER: Meet the ocean’s natural seawall ‘ako ‘ako ‘a the cauliflower coral

Let’s go surfing today and ride a perfect 10-foot wave at Sunset Beach, then afterwards hang out in the sun on the beautiful, wide, sandy beach for the afternoon. At times in the past we could say this, but now things have changed. There are very few perfect 10-foot waves at Sunset Beach anymore, and there is no wide, sandy beach to relax on!

Back in the old days when Sunset Beach was called by its Hawaiian name, Paumalu, the reef was covered in cauliflower coral, which are known in Hawai‘i as ko‘a or ‘ako ‘ako ‘a. This rock-hard coral grows upwards about a foot high, and causes a drag on the underside of the waves, making the waves break hollow and a good shape for surfing. The corals shape the waves, but they also protect the beach from erosion!

A 10-foot wave at Sunset Beach has over 3,000 pounds of energy! You know this quite well as a surfer if you get caught inside when a set comes and you break your surfboard or your back! The energy of the waves should be driven into the rock-hard reef. Cauliflower corals are one of the only corals in Hawai‘i that can grow in the wave impact zone, as they have a rock-hard calcium carbonate skeleton and branches that let the waves’ energy pass through the coral and on into the reef. The problem is if the cauliflower corals die, the energy of the waves bypasses the reef and directly hits the beach, removing the sand and causing homes to fall into the sea.

Cauliflower corals grow quickly. We have measured their growth over the past five years, which surprised us scientists, as some of the ko‘a grew upwards of three inches a year. So, theoretically, the corals should grow upwards faster than sea-level rise, which would help keep beach erosion to a minimum.

Cauliflower corals do not live very long, and when the soft coral polyp tissue dies the coral skeleton remains behind, and new corals will grow on top of the old, dead coral. This is how coral reefs build over many years.

Cauliflower corals come in many different colors, from brown, pink, purple, yellow and green. The colors are caused by algae that grows in the coral tissue that produces sugars the coral polyps feed on. Different corals have different-colored algae farms growing in their tissue.

The corals must grow in shallow water because they need sunshine to grow their algae farm.

Over the past 10 years the corals at Sunset Beach died, but what was very odd is when they died their hard skeleton dissolved.

As a career marine biologist who has done over 3,000 scuba dives studying corals, I have never seen a rock-hard coral dissolve into nothing but mud, but that is exactly what I filmed going on out on the reefs along O‘ahu’s North Shore over the past 10 years. When the coral disintegrated, the beach started to erode faster and, sure enough, a few homes fell into the sea. In physics we simply call this “cause and effect.”

What killed the cauliflower corals along O‘ahu’s North Shore over the past 10 years? It wasn’t sea temperatures, because on other islands that had an increase in sea temperatures the corals grew and continue to be healthy. It wasn’t sunscreen, because the currents along O‘ahu’s North Shore are strong and sunscreen washes away quickly. Leaking cesspools are definitely causing some corals to die, but that is usually very close to shore, and the ko‘a at Sunset Beach died way out on the outer reefs at 40 feet deep, which could not be affected by sunscreen or sewage. We do have lots of evidence that military submarines and helicopters discharge an electrical current into the sea that can cause the corals to dissolve. This is called “marine corrosion.” The corals started to die at the same time the Navy started their electromagnetic-weapons training near shore on O‘ahu in 2014, so there is a timeline, and the Navy has NEVER disagreed with this timeline or its possible effects on the reef.

Along Kaua‘i’s North Shore, our cauliflower corals also died in huge numbers from 2012 to 2015, and that was the same time the Navy was conducting their microwave-weapons training near shore. In 2015 we challenged the Navy about this issue, and they agreed to move their submarine and helicopter training way offshore. And guess what?

All the cauliflower corals grew back, and the reef has now grown two feet upwards, which is once again protecting the beach! The Kaua‘i corals were growing super fast at the same time people were claiming that all the corals were dying due to “climate change” and a two-degree rise in sea temperatures! Sometimes simple direct observation is better than scientific theory.

Recently, we got the military along O‘ahu’s North Shore to stop most of their helicopter and submarine war games, which has made our neighborhoods much more peaceful, and we will see if our corals start to grow back like they did in Kaua‘i! We now know that there is no need to captive-produce or engineer “super corals” or make artificial reefs because if you remove the stress that was killing the original corals the reef will grow back all on its own quite quickly! We have documented an entire mile-long reef on Kaua‘i growing back in six years to the height it was in 2010 before the corals started to die! Nature is pretty darn responsive if we just give her a chance!

I am doing a full documentary movie about the life, death and rebirth of our Kaua‘i North Shore corals that will be quite dramatic! It will be out on my YouTube channel soon so please sign up for all the free worldwide underwater movie series at underwater2web.


Terry Lilley is a marine biologist living in Hanalei Kaua‘i and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawaii go to
Source: The Garden Island

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