Hawaiʻi County Department of Parks and Recreation informs the public that Kahaluʻu Beach Park will be closed from May 16 – 21 due to anticipated coral spawning events.

According to the Division of Aquatic Resources and Eyes of the Reef Network, cauliflower coral (Pocillopora meandrina) was once abundant on shallow coral reefs along West Hawai’i, including Kahaluʻu Bay. However, environmental stressors and very high ocean temperatures impacted West Hawai’i in 2015 and again at the end of 2019, leading to catastrophic bleaching and mortality of more than 90% of the cauliflower coral population in Kahaluʻu Bay.

Natural reproduction events are essential to recovering from the loss in the coral population. For more than a decade, researchers have observed annual broadcast spawning events for cauliflower corals and can now accurately predict when they will likely occur based on season, solar, tidal, and lunar cycles.

During broadcast spawning events, corals emit reproductive cells (“gametes”) into the water column, which the tides carry to mix and generate planktonic coral larvae. The high volume of daily visitors to Kahaluʻu Bay may cause harm to larval corals due to physical and chemical disturbances (e.g., sunscreens and other personal care items) in the bay’s surface waters. In recent studies, oxybenzone chemicals in sunscreens were shown to cause damage to larval corals and prevent successful settlement on the reef.

Minimizing pollutants and physical disturbances within the spawning period in their natural environment will help ensure that corals can successfully reproduce and settle properly.

The Department of Parks & Recreation and the Kahaluʻu Bay Education Center appreciate the public’s understanding and respect for this critical coral recovery and replenishment process at Kahaluʻu Bay. We also apologize for any inconvenience the temporary closure may cause.

For more information, please contact the Kahaluʻu Bay Education Center at (808) 895-1010.