VIDEO: Coral Spawning Observed After Popular Beaches Closed

New life is developing in West Hawai´i waters.

The DLNR Division of State Parks and Hawai´i County have announced the closures of parking lots to multiple popular beach areas over the coming week to aid the natural process of coral spawning in the accompanying bays. Information specialists have also been at those sites to discourage people from entering the water at specific times.

On Friday, May 28, Project Director for Kahalu`u Bay Education Center and Outreach Coordinator at The Kohala Center Cindi Punihaole said she has already seen evidence of the effort’s success.

“Coral spawning (was) observed yesterday at Kahalu´u and Waialea. (I’m) thankful that (the) county and state allowed park closures,” Punihaole said. “This week is a very sensitive time for cauliflower corals. Community and visitors are (being) very respectful, too.”

Waialea Bay was closed for half-days on Friday and Saturday, while Kahalu´u Bay was closed down Friday and will remain so until June 5.

DAR Observes Spawning Process on Kohala Coast

Shortly after dawn on both Friday and Saturday, a trio of aquatic biologists with the DLNR Division of Aquatic Resources (DAR) carefully watched coral colonies at Waialea Bay at Hāpuna Beach State Recreation Area (SRA). 

Once a year, with spring tides and the full moon, corals spawn and send millions of tiny gametes into the water column. However, the annual cycle can be broken. 

“A lot of factors come into play,” said DAR Fish and Habitat Monitoring Planner Lindsey Kramer. “Water temperature and salinity are important. Rain events can cause the colonies to wait until the next lunar cycle. The moon cycles are the primary drivers of these spawning events of cauliflower corals.”  

She and her colleagues hope the gametes will fertilize with nearby colonies, float to the surface, and within 24-48 hours produce larvae to reseed reef structures with new corals. 

Cauliflower coral (Pocillopora meandrina) reefs in west Hawai‘i waters were heavily impacted by a 2015 mass coral bleaching event.

“We’re down to about 5% of the population of this species in West Hawai‘i,” Kramer said. “Cauliflower coral are especially susceptible to bleaching, so with that 95% loss of cover these spawning events are vitally important. We need to do everything possible to help these reefs recover through this natural reproductive cycle.”  

Researchers have now recorded active spawning over the past five years. To give the coral recovery even more of an advantage, this year, in cooperation with the DLNR Division of State Parks, the parking lot at the bay was closed and people were asked to avoid going into the water before noon each day. 

At the entrance State Parks Outreach Specialist Dena Sedar explained the reason for the closure to would-be snorkelers.

“Everyone really understood the reasons not to interrupt the coral spawning. One of the biggest is to keep personal care products out of the water,” she said.  

Scientists say sunscreens form a surface on the water that interact with the coral larvae. Reef-safe sunscreen dispensers are scheduled to be installed at the Waialea Bay Section of the SRA later this year. 

“It’s good to let them do their thing without people around as hopefully that allows more settling later on,” DAR Aquatic Biologist Chris Teague said, adding that observing results of spawning is tricky. “Some are carried off-shore and it could be a couple of months before they’re back down on the reef. They might settle back at Waialea, but the spawn could go elsewhere within the region or even across the state.”

With the resurgence in tourism, coral experts are renewing pleas to ocean-goers to be aware of their personal impacts on marine environments. Do not touch, sit, or walk on corals. Use sun-protective clothing and head wear and use only reef-safe sunscreens.