MEPS 293:69-76 (2005)  -  doi:10.3354/meps293069

ABSTRACT: The growth rate of Acropora cervicornis branch tips maintained in the laboratory was measured before, during, and after exposure to elevated nitrate (5 and 10 µM NO₃^–), phosphate (2 and 4 µM P-PO₄³) and/or pCO₂ (CO₂ ~700 to 800 µatm). The effect of increased pCO₂ was greater than that of nutrient enrichment alone. High concentrations of nitrate or phosphate resulted in significant decreases in growth rate, in both the presence and absence of increased pCO₂. The effect of nitrate and phosphate enrichment combined was additive or antagonistic relative to nutrient concentration and pCO₂ level. Growth rate recovery was greater after exposure to increased nutrients or CO₂ compared to increased nutrients and CO₂. If these results accurately predict coral response in the natural environment, it is reasonable to speculate that the survival and reef-building potential of this species will be significantly negatively impacted by continued coastal nutrification and projected pCO₂ increases.

KEY WORDS: Acropora cervicornis · Nutrient enrichment · pCO₂ · Growth rate