You may not have seen one of these beautiful, bright-orange Hawai‘i cup corals, but if you have ever been on a boat along the coastline here in Hawai‘i, you have been right above thousands of them
Most Hawai‘i stony (hard) corals grow on top of the shallow lava reefs because the coral grow algae in their tissue for food. This algae needs sunlight to photosynthesis and produce sugars to stay alive. This is why most hard corals do not grow any deeper then about 80 feet deep because the sunlight won’t get down that deep to be used by the algae growing within the coral polyps.
On the other hand, the orange cup coral grows in the dark where there is no sunshine. You can find thousands of these small, inch-long corals clustered together on the roof of caves or in deep cracks in the reef. Since the lava reef here in Hawai‘i have lots of lava tubes running through them, there are millions of these beautiful cup corals growing in the dark lava tubes. Sometimes I will be scuba diving right under large tour boats going by overhead and I will enter a dark, black cave, turn on my bring video lights and be surrounded by bright orange and red walls. It is totally an amazing site that the folks above do not even know they are traveling right over.
These cup corals feed by being in high current areas where they put out their soft tentacles and filter small organisms that float by in the sea water. If the cup corals are disturbed by a diver or a predator then they will retract their soft tentacles into their little orange hard shell that looks like a little orange tea cup.
Who eats these beautiful little hidden animals? Not much, because they have stinging cells in their tentacles, but your new IPhone or computer you purchase just may wipe out this entire species from the sea.
The human need for electronics these days causes the companies who build the equipment we purchase to have a great need for rare metals and minerals. All of these fun new electronic devices have rare metals in them to work. So where do these rare metals come from? Up until recently the metals were mined on land, but the mineral deposits that were easy to get to are running out. So now the companies are starting to mine the sea floor to get deposits of minerals that are just sitting out in the open on the bottom of the sea.
Orange cup corals along with most of the sea creatures that live in the deep ocean need the minerals in the sea water to develop their colors and also maintain their feeding and reproduction. The minerals sitting on the sea floor act like food for these creatures, and if they are removed to be used in electronics, then the sea creatures will die.
What goes on at the bottom of the sea is very important because the sea creatures absorb carbon from the atmosphere and produce much of the oxygen we breath. So it is important to understand this living cycle on earth and make sure we do not disturb the sea floor in any way, as that could lead to our own self-destruction.
You may not see these orange cup corals, but they are helping you breath clean air and stay alive. Nature is pretty darn amazing.
You can see the beautiful orange cup corals in their dark caves under the reef in the video “The World’s Guide to Hawaiian Reef Creatures” at underwater2web.com, and also follow my marine-life Instagram post at terry.lilley
Hopefully, soon we will also have a full online marine life educational series for the students who are at home due to the Coronavirus outbreak.
Aloha from under the waves.
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Terry Lilley, a marine biologist, lives in Hanalei.
His websites include underwater-2web.com and www.gofundme.com/5urrm4zw.
