'Tis the season: More daytime spawning in Hawaii!
Spawning cauliflower coral (Pocillopora meandrina) within the Shark Island lagoon, French Frigate Shoals, part of the Hawaiian Islands National Wildlife Refuge and the Papahanaumokuakea Marine National Monument. Image credit: Mark Sullivan/ USFWS
Last month was filled with wonderful reports about coral spawning:
- Dana Riddle writes for Advanced Aquarist about the daytime spawning of Porites lutea.
- Matt Wandell blogs about the Steinhart's expedition to the Philippines where they record videos of nighttime spawning of Acropora sp.
- During the same expedition, soft coral spawning ... in more than one way.
- And now ...
Daytime Spawning in Hawaii of Pocillopora meandrina
Video credit: Lindsey Kramer/ USFWS
"On May 19th and 20th, just after sunrise, USFWS staff and volunteers observed a broadcast spawning event for the coral species Pocillopora meandrina (cauliflower coral) within the Shark Island lagoon, French Frigate Shoals, part of the Hawaiian Islands National Wildlife Refuge and the Papahanaumokuakea Marine National Monument. Gamete release must be synchronous among the population to ensure fertilization success, and timing cues are likely related to the lunar cycle.
Beginning in 2000, UH Sea Grant's ReefWatchers, led by Sara Peck and volunteer Joan Prater, began observing broadcast spawning of cauliflower coral on Hawai’i Island. Broadcast spawning events have since been observed annually on the Big Island by ReefWatchers, and a predictive model is being developed based on oceanographic conditions, seasonality, water temperature and lunar cycles. Lindsey Kramer adjusted the 2011 predictions for the Big Island spawning to fit the later sunrise and moonset at the French Frigate Shoals."
The first spawning activity was observed on May 19, when observers monitored 50 coral colonies, and approximately 30% of the observed colonies spawn in a matter of minutes. On May 20, observers monitored 70 coral colonies, and 95% of the observed colonies spawn in less than 15 minutes.