Calcification rates of crustose coralline algae (CCA) derived from Calcification Accretion Units (CAUs) deployed at coral reef sites in Batangas, Philippines in 2012 and recovered in 2015 (NCEI Accession 0162831)

Laboratory experiments reveal calcification rates of crustose coralline algae (CCA) are strongly correlated to seawater aragonite saturation state. Predictions of reduced coral calcification rates, due to ocean acidification, suggest that coral reef communities will undergo ecological phase shifts as calcifying organisms are negatively impacted by changing seawater chemistry. Calcification accretion units, or CAUs, are used by the NOAA Coral Reef Ecosystem Program (CREP) to assess the current effects of changes in seawater carbonate chemistry on calcification and accretion rates of calcareous and fleshy algae.

CAUs, constructed in-house by CREP, are composed of two 10 x 10 cm flat, square, gray PVC plates, stacked 1 cm apart, and are attached to the benthos by SCUBA divers using stainless steel threaded rods. Deployed on the seafloor for a period of time, calcareous organisms, primarily crustose coralline algae and encrusting corals, recruit to these plates and accrete/calcify carbonate skeletons over time. By measuring the change in weight of the CAUs, the reef carbonate accretion rate can be calculated for that time period.

The calcification rate data described here were collected by CREP from CAUs moored at fixed climate survey sites located on hard bottom shallow water (< 15 m) habitats in the Philippines, in accordance with protocols developed by Price et al. (2012). Climate sites were established by CREP to assess multiple features of the coral reef environment (in addition to the data described herein) from March 2012 to June 2015, and five CAUs were deployed at each survey site.

In conjunction with benthic community composition data (archived separately), these data serve as a baseline for detecting changes associated with changing seawater chemistry due to ocean acidification within coral reef environments.

实验室实验揭示，皮壳状珊瑚藻（CCA）的钙化率与海水方解石饱和状态密切相关。由于海洋酸化导致的珊瑚钙化率降低的预测表明，珊瑚礁群落将经历生态阶段的转变，因为钙化生物受到海水化学变化的负面影响。珊瑚礁生态系统项目（NOAA Coral Reef Ecosystem Program，CREP）使用钙化积累单元（Calcification Accretion Units，CAUs）来评估海水碳酸盐化学变化对钙化藻类和肉质藻类钙化及积累率的影响。CAUs由CREP内部构建，由两块10 x 10 cm的平坦、方形、灰色PVC板组成，板间间隔1 cm，并由潜水员使用不锈钢螺纹杆固定在海底生物上。这些单元在海底放置一段时间后，钙化生物，主要是皮壳状珊瑚藻和附着珊瑚，会附着到这些板上并随着时间的推移积累/钙化碳酸骨骼。通过测量CAUs重量的变化，可以计算出该时间段珊瑚礁的碳酸积累率。所描述的钙化率数据由CREP收集，这些数据来自菲律宾硬底浅水（< 15 m）栖息地上的固定气候调查站点处的CAUs，这些数据收集符合Price等（2012）制定的协议。从2012年3月到2015年6月，CREP建立了气候站点以评估珊瑚礁环境的多个特征（除本描述之外的数据），每个调查站点部署了五个CAUs。与海底群落组成数据（分别存档）相结合，这些数据为检测由于海洋酸化导致的海水化学变化与珊瑚礁环境相关的变化提供了一个基准。