Analysis of Recruitment of Pocillopora damicornis under climate change scenarios

Abstract

Ocean warming and acidification are among the greatest threats to coral reefs, and severe bleaching events have become more common in recent decades, putting coral reefs at risk of extinction. The loss of coral reefs would have a catastrophic cascading effect on all marine life and would mean a loss of one the world’s largest pools of biodiversity. There have been many studies conducted on the individual effects of warming and acidification on coral response, but not as many that attempt to assess the combined effect, which could possibly be synergistic. This study looks at the individual and combined effects of warming and acidification on Pocillopora damicornis under four different treatments: ambient, heated, acidified, and heated/acidified, in a multi-annual mesocosm experiment. P. damicornis were able to recruit under these stressors, and the recruits were measured for size, condition, and abundance during two separate assessments and the differences across treatments and within treatments were analyzed. The results showed that more bleaching occurred in the heated treatments than in the nonheated treatments, and that mean size significantly increased in the treatments with acidification from July to October.