Aquatic biologists from the State Department of Lands and Natural Resources observed spawning of light coral at the Hapuna Beach State Recreation Area in Waialea Bay today and Friday.
Each year, with high tides and a full moon, corals reproduce by sending millions of gametes into the water column. The gametes fertilize neighboring colonies, float on the surface of the water, and produce larvae within a day or two. The larvae then help reseed the reefs with new corals.
Scientists have observed active spawning for the past five years, but the annual event can be disturbed.
“There are many factors at play,” said Lindsey Kramer, fish and habitat monitoring planner for DLNR’s aquatic resources division, in a statement. “The temperature and the salinity of the water are important. Rainy events can make colonies wait until the next lunar cycle. Lunar cycles are the primary drivers of these cauliflower coral spawning events. “
Biologists were monitoring spawning of cauliflower corals, which were heavily affected by the 2015 coral bleaching in Hawaii.
“We have dropped to about 5% of the population of this species in western Hawaii. Cauliflower corals are particularly susceptible to bleaching, so with this 95% coverage loss, these spawning events are vitally important, ”Kramer said. “We need to do everything we can to help these reefs recover through this natural reproductive cycle.”
The DLNR worked with Hawaii County and the Kahuluu Bay Education Center to close the bay parking lot from Friday to June 5 to help with coral recovery.
The public was also asked to avoid entering the water before noon.
“It’s good to let them do their job without anyone, as I hope that will allow more to settle down later,” Chris Teague, DAR aquatic biologist, said in a statement.
It can be difficult to see the coral spawn.
“Some are being transported offshore and it may take a few months before they get back down to the reef. They could settle in Waialea, but the spawning could go elsewhere in the region or even across the state, ”Teague added.
As tourism picks up in Hawaii, coral experts are asking those who use the ocean to be aware of their impacts on marine environments.
Touching, sitting or walking on corals and using harmful sunscreens can harm them.