KAILUA-KONA — Kahaluu Beach Park will be closed on May 20-21 due to anticipated coral spawning events, the Hawaii County Department of Parks and Recreation announced in a release Friday.
According to the Division of Aquatic Resources and Eyes of the Reef Network, cauliflower coral was once abundant on shallow coral reefs along West Hawaii, including Kahaluu Bay. However, catastrophic conditions in recent years tied to environment stressors and high ocean temperatures resulted in the bleaching and mortality of more than 90 percent of the regional population of cauliflower coral.
To recover from this loss in the coral population, natural reproduction events are critically important, the release continued. 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 into the water column, which are carried by the tides to mix and generate planktonic coral larvae, the release said.
The high volume of daily visitors to Kahaluu Bay may cause harm to larval corals due to physical and chemical disturbances in surface waters of the bay. In recent studies, oxybenzone chemicals in sunscreens were shown to cause damage to larval corals and prevent successful settlement on the reef, the release stated.
After many years of unsuccessful cauliflower coral larvae settlement within a laboratory setting, the very first successful settlement occurred last year at the Natural Energy Laboratory of Hawaii Authority (NELHA) on Hawaii Island, Parks and Rec wrote in its release. Undisturbed by pollutants and human activity, it took as little as 24 hours for coral gametes to find proper colony areas within the tanks.
Minimizing pollutants and physical disturbances within the spawning period in their natural environment will help ensure that corals are able to successfully reproduce and settle properly.
For more information, please contact the Kahaluu Bay Education Center at 895-1010.