By Pacific Island Times News Staff
Some types of corals recover from decimation faster than others, scientists discovered in a new study released this week by the Palau International Coral Reef Center.
The PICRC study looked into the Ngetngod reef, which was wrecked by Super-Typhoons Bopha and Haiyan that pounded into Palau in 2012 and 2013 and caused catastrophic loss of corals on some eastern outer reefs.Â
The center said several sites where corals were previously abundant were left bare, but some reefs have started to recover in the decade since.
The decimation of coral colonies in Ngetngod reef provided scientists an opportunity to measure the post-disaster recovery time for marine invertebrates, PICRC said.
Led by Dr. Piera Biondi of PICRC and Dr. Liam Lachs of Newcastle University, the study focused on the three most common branching coral genera-- Acropora, Pocillopora and Stylophora-- which were found to have recouped at varying rates.
“By 2020, Pocillopora colony density far exceeded pre-typhoon levels. However, despite the recovery of Acropora colony density by 2020, populations remained dominated by smaller colonies," PICRC said.
Scientists found that demographic recovery varies depending on the life history of the coral.
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The research indicates that it takes around four years for pocilloporids to recover because this coral genus spawns year-round, but Acropora, which typically has only one spawning event per year, requires more than eight years to recover.
The study also demonstrates that tracking coral colony density (such as the number of colonies per m2 of seabed) instead of coral coverage can predict recovery two to four years earlier.
While the usual approach to monitoring reef health is to track the percentage of seabed covered with live corals, this study, recently published in the scientific journal, Coral Reefs, went a step further by also measuring the size of each coral colony as part of a long-term dataset that PICRC has gathered since 2001.
This analysis gave further insights into the coral populations, such as the density of corals and the distribution of different coral sizes.Â
