Radiocarbon-based ages and growth rates of Hawaiian deep-sea corals

• Published in: Marine ecology. Progress series (Halstenbek) 2006-12, Vol.327, p.1-14
• Main Authors: Roark, E. Brendan, Guilderson, Thomas P., Dunbar, Robert B., Ingram, B. Lynn
• Format: Article
• Language: English
• Subjects: Age; Animal age determination; Corals; FEATURE ARTICLE; Oceans; Radiocarbon; Radiocarbon dating; Skeleton; Specimens; Surface water; Sustainable fisheries management
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps327001

The radial growth rates and ages of 3 different groups of Hawaiian deep-sea ‘corals’ were determined using radiocarbon measurements. Specimens ofCorallium secundum,Gerardiasp., andLeiopathes glaberrimawere collected from 450 ± 40 m depth at the Makapuu deep-sea coral bed off the southeast coast of Oahu, Hawaii, USA, using a submersible vessel (PISCES V). Specimens ofAntipathes dichotomawere collected at 50 m depth off Lahaina, Maui, Hawaii. The primary source of carbon to the calciticC. secundumskeleton isin situdissolved inorganic carbon (DIC). Using ‘bomb14C’ time markers we calculated radial growth rates of ~170 μm yr–1and ages of 67 to 71 yr for specimens ofC. secundumup to 28 cm tall.Gerardiasp.,A. dichotoma, andL. glaberrimahave proteinaceous skeletons, and labile particulate organic carbon (POC) is their primary source of architectural carbon. Using14C we calculated a radial growth rate of 15 μm yr–1and an age of 807 ± 30 yr for a live collectedGerardiasp., showing that these organisms are extremely long lived. Radiocarbon measurements taken from the inner and outer portions of basal cross sections of 4 sub-fossilGerardiasp. samples showed growth rates (range 14 to 45 μm yr–1) and ages (range 450 to 2742 yr) similar to that of the live collected sample. Similarly, with a growth rate of