Radiocarbon (<sup>14</sup>C) measurements are an important tool for determining growth rates of bamboo corals, a cosmopolitan group of calcitic deep-sea corals. Published growth rate estimates for bamboo corals are highly variable, with potential environmental or ecological drivers of this variability poorly constrained. Here we systematically investigate the application of <sup>14</sup>C for growth rate determinations in bamboo corals using 55 <sup>14</sup>C dates on the calcite and organic fractions of six bamboo corals (identified as Keratoisis sp.) from the western North Atlantic Ocean. Calcite <sup>14</sup>C measurements on the distal surface of these corals and five previously published bamboo corals exhibit a strong one-to-one relationship with the <sup>14</sup>C of dissolved inorganic carbon (DI<sup>14</sup>C) in ambient seawater (r<sup>2</sup>=0.98), confirming the use of Keratoisis sp. calcite <sup>14</sup>C as a proxy for seawater <sup>14</sup>C activity. Radial growth rates determined from <sup>14</sup>C age-depth regressions, <sup>14</sup>C plateau tuning and bomb <sup>14</sup>C reference chronologies range from 12 to 78μmy<sup>-1</sup>, in general agreement with previously published radiometric growth rates. We document potential biases to <sup>14</sup>C growth rate determinations resulting from water mass variability, bomb radiocarbon, secondary infilling (ontogeny), and growth rate nonlinearity. Radial growth rates for Keratoisis sp. specimens do not correlate with ambient temperature, suggesting that additional biological and/or environmental factors may influence bamboo coral growth rates.
|Number of pages||15|
|Journal||Deep-Sea Research Part I: Oceanographic Research Papers|
|Publication status||Published - 1 Aug 2015|
- Bamboo coral
- Deep-sea coral
- Growth rates