Assessment of net community production and calcification of a coral reef using a boundary layer approach. Issue 8 (10th August 2016)

• Record Type: Journal Article
• Authors: Takeshita, Yuichiro; McGillis, Wade; Briggs, Ellen M.; Carter, Amanda L.; Donham, Emily M.; Martz, Todd R.; Price, Nichole N.; Smith, Jennifer E.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 8(2016:Aug.)
• Page Start: 5655
• Page End: 5671
• Publication Date: 2016-08-10
• Subjects: coral reef -- net community calcification -- net community production -- benthic boundary layer -- pH -- oxygen; Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/2016JC011886
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: Coral reefs are threatened worldwide, and there is a need to develop new approaches to monitor reef health under natural conditions. Because simultaneous measurements of net community production (NCP) and net community calcification (NCC) are used as important indicators of reef health, tools are needed to assess them in situ. Here we present the Benthic Ecosystem and Acidification Measurement System (BEAMS) to provide the first fully autonomous approach capable of sustained, simultaneous measurements of reef NCP and NCC under undisturbed, natural conditions on time scales ranging from tens of minutes to weeks. BEAMS combines the chemical and velocity gradient in the benthic boundary layer to quantify flux from the benthos for a variety of parameters to measure NCP and NCC. Here BEAMS was used to measure these rates from two different sites with different benthic communities on the western reef terrace at Palmyra Atoll for 2 weeks in September 2014. Measurements were made every ∼15 min. The trends in metabolic rates were consistent with the benthic communities between the two sites with one dominated by fleshy organisms and the other dominated by calcifiers (degraded and healthy reefs, respectively). This demonstrates the potential utility of BEAMS as a reef health monitoring tool. NCP and NCC were tightly coupled on time scales of minutes to days, and light was the primary driver for the variability of daily integrated metabolic rates. No correlation between CO2 levels and daily integrated NCC was observed, indicating that NCC at these sites were not significantly affected by CO2 . Key Points: We present an autonomous approach to measure coral reef net calcification and production rates Net community production and calcification are coupled on time scales from minutes to days Available light is the primary driver for net community calcification (NCC); no relationship between Ω and NCC was observed