Recovery of reef-scale calcification following a bleaching event in Kāne'ohe Bay, Hawai'i

Abstract

Increasing anthropogenic disturbances have driven declines of many coral-dominated reef states, threatening critical ecosystem functions such as reef-scale calcification and accretion. Few studies have investigated the effect of coral bleaching on reef-scale calcification. In this study, we monitored bay-wide alkalinity anomalies in Kāne'ohe Bay, Hawai'i along an inshore-offshore transect as a proxy for net calcification during the 2015 coral bleaching event and following recovery over a full seasonal cycle. We observed no net calcification in October 2015 during the bleaching event followed by a recovery to significant, positive net calcification rates in June 2016, November 2016, and February 2017 across a range of seawater temperatures and hydrodynamic conditions. Post-bleaching net calcification rates were not significantly different between survey dates and agreed with the range of pre-bleaching net calcification rates from a previous study suggesting that net calcification in Kāne'ohe Bay had fully recovered following the 2015 bleaching event.