WAIKIKI AQUARIUM / 2007
Rice coral spawn at the Waikiki Aquarium.
Coral couplings at core of special aquarium night
Hanau ka Uku-ko alo a
Hanau kana, he Alo-alo a puka
Born the coral polyp
Born of him a coral colony emerged ...
- The Kumu Lipo
The sandy shores of Waikiki Beach will fill with human life again this Memorial Day as sunset approaches, to remember family and friends no longer with us. As the brilliant pinks, blues, purples and oranges of sunset fade into darkness, a sea of candles will be seen, quietly sailing out beyond the reef, each floating candle representing a loved one remembered.
As the sky darkens, only the candles will be seen, quietly bobbing along on a journey we cannot join, creating a mesmerizing goodbye.
‘Coral Spawning and Reef Romance’
» When: 8 to 10 p.m. June 6
» Place: Waikiki Aquarium
» Cost: $16; $12 aquarium members. Minimum age 14.
» Call: 923-9741
And just in time to remind us of the continuity of life, the corals beneath those waves will bring us back to Waikiki again in a little more than a week to celebrate the coral spawning that will repopulate the coral reefs.
When the time is right - most experts say two to four days after a new moon in June or July - tiny bubbles containing coral egg and sperm can be seen floating upward to the ocean's surface in the waters around our islands. As the sperm break free of their "space bubbles," they somehow find and pair with eggs of other coral within their species, and the next generation of coral begins.
We know this because each year marine biologists learn a little more and share it with the rest of us at the Waikiki Aquarium's annual "Coral Spawning and Reef Romance" event.
It seems rice corals spawn two to four days after the new moon all over Hawaii. Lucky for us, this includes the rice corals in the "Edge of the Reef" exhibit on the aquarium grounds.
Robert Richmond and his colleagues at the University of Guam Marine Laboratory have posted their research online, suggesting that coral eggs can distinguish among the different kinds of sperm present in the waters during mass spawning.
"They usually reject sperm which originates from their own parent colony, but readily accept sperm from different individuals of the same species," he reports. The team has been able to get sperm from one species of coral to fertilize eggs of related but different species.
"Such crosses may be one reason for the wide variety of coral forms on the reef," Richmond explains.
But he adds, "On the pollution front, we've found that freshwater runoff alone can have disastrous effects on coral fertilization rates - with a 15 percent drop in sea-water salinity causing nearly a 90 percent drop in coral fertilization rate.
"Add red soil to the runoff, and the situation gets worse. We are also beginning to test the effects of pesticides on coral reproduction as we need to know if these chemicals will be a problem, based on our present knowledge that chemical cues are very important to the success of corals during their once-a-year breeding period."
This is a sobering reality since the reefs surrounding our islands provide a home for a wide diversity of marine life, from microscopic organisms to whale-size mammals.
This year's "Coral Spawning" event will be held at the Waikiki Aquarium June 6.
It's a great opportunity to learn a little coral biology and join a tour of the exhibits with aquarium biologists. Courtship and nesting behaviors of many of the fish will also be observed on this special night.
Longtime residents might notice that many of the landscape plants around the aquarium are native Hawaiian plants. This evening will be a good opportunity to see which native plants might thrive in seaside landscapes in other places around the islands.
teaches botany, ethnobotany and environmental science at Chaminade University. Her column runs on the last Monday of the month. E-mail her at firstname.lastname@example.org