title: Continuous-flow complete-mixing system for assessing the effects of environmental factors on colony-level coral metabolism.
abstract: A small-scale chamber experimental system was designed to study the effects of temperature on colony-level coral metabolism. The system continuously supplies fresh seawater to the chamber, where it is mixed immediately and completely with the seawater already present. This continuous-flow complete-mixing system (CFCM system), in conjunction with theoretical equations, allows quantitative determination of chemical uptake and release rates by coral under controlled environmental conditions. We used the massive hermatypic coral Goniastrea aspera to examine variations in pH, total alkalinity, and total inorganic carbon for 16 days at 27 degrees C under controlled light intensities (300 and 0 micromol m(-2) s(-1)). We confirmed the stability of the CFCM system with respect to coral photosynthetic and calcification fluxes. In addition, we obtained daily photosynthetic and calcification rates at different temperatures (27 degrees C, 29 degrees C, 31 degrees C, and 33 degrees C). When seawater temperature was raised from 31 degrees C to 33 degrees C, the gross primary production rate (Pgross) decreased 29.5%, and the calcification rate (G) decreased 85.7% within 2 days. The CFCM system allows quantitative evaluation of coral colony chemical release and uptake rates, and metabolism.
authors.affiliation: Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan. fujimura@sci.u-ryukyu.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujimura
authors.forename: Tomihiko
authors.initials: T
authors.lastname: Higuchi
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Shiroma
authors.forename: Takemitsu
authors.initials: T
authors.lastname: Arakaki
authors.forename: Asha Mansour
authors.initials: AM
authors.lastname: Hamdun
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Nakano
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Oomori
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D001681:Biological Assay / Q000295:instrumentation* / Q000379:methods*; D002118:Calcium / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002254:Carbonates / Q000737:chemistry / Q000378:metabolism; D004777:Environment; D010777:Photochemistry; D012119:Respiration; D012996:Solutions; D013696:Temperature; D013997:Time Factors
chemical_list: D002254:Carbonates; D012996:Solutions; D002244:Carbon; D002118:Calcium