New UVI study has far-reaching implications for coral worldwide
CHARLOTTE AMALIE – Caribbean corals have declined by about 50 percent in the past 50 years. In 2005, coral reefs in the Virgin Islands were severely impacted by high temperatures and disease.
“Coastal pollution, storms, and warm water can stress a coral out, which is why we’re looking at what’s going on in deeper offshore habitats,” said Daniel Holstein, one of the researchers, in a news release. “These deeper habitats tend to be cooler and less strenuous for corals-and thus, coral spawning may be more spectacular.”
In this latest study, the researchers focused on mountainous star corals, which reproduce by broadcast spawning. This means that the corals release their eggs and sperm in the water during a highly synchronized event.
The researchers used remote cameras at a field site off of the island of St. Thomas and laboratory observations during broadcast spawning events. This revealed the corals that lived in waters between 98 and 492 feet released their eggs in near synchrony with shallow-water corals. However, the deeper corals seemed more successful.
“The reefs that produce more larvae are more likely to be successful in seeding the reefs with their offspring,” said Clair Paris, one of the researchers. “Protecting these potent reproductive deep refuges could represent the key to the survival of coral reefs for future generations.”
The findings reveal that these deep reefs may represent a way for corals to survive a warming world. With the deeper water, the corals don’t have to deal with as much heat stress as corals in shallower waters.
The findings are published in the journal Scientific Reports.