Black coral of the Azores
2300 year old black coral - Azores
Published in Marine Ecological Progress Series 2013
Variability in growth rates of long-lived black coral Leiopathes sp. from the Azores
Five colonies of black coral Leiopathes sp. were collected as bycatch from depths of 293 to 366 m from the Condor, Açor, and Voador seamounts (Azores region). The colonies had axial diameters between 4.9 and 33.1 mm and heights between 43 and 175 cm. Their ages and radial growth rates were estimated using radiocarbon dating. Results indicated that the smallest and largest colonies had similar radial growth rates of 5 to 7 μm yr−1, whereas the other 3 colonies had grown more rapidly by a factor of 3 to 5 at ~20 to 30 μm yr−1. Colony lifespan ranged between 265 ± 90 and 2320 ± 90 yr. Fine-scale sampling along a radial transect from the edge to the center of the 2320 yr old Leiopathes sp. revealed variable growth rates throughout the colony lifespan. Slower radial growth rates of ~4 to 5 μm yr−1 were recorded over the initial 1600 yr and the last 300 yr of its life span, and a period of more rapid growth (20 μm yr−1) over the intermediate 400 yr of its life. Variability in radial growth rates among colonies resulted in colony ages that were not linearly correlated to colony axis diameter or height. Our findings of great longevity and slow growth rates for Leiopathes sp. agree with other Leiopathes sp. age and growth studies, indicating that colony and population recovery from damage or removal may take centuries to millennia.
Leiopathes sp. (A) Complete type-specimen (height: 62 cm; axis dia- meter: 18 mm) assigned to morphotype 3 (DOP reference collection). Esti- mated age is 300 to 1700 yr based on the growth rates provided in this study. (B) Colony section used in sample extractions for DOP-1985. (C) Frame grab from the New Wave Research micromill computer showing the sample series taken from the edge of DOP-1985, with an overlap of extraction paths (0.5 mm bit width). (D) Post-ex- traction surface of the coral section showing the narrower sample series at the edge, 3 intermediate radial samples (full bit width at 0.5 mm), and the axial core extraction. The serial extractions were performed with New Wave Research micromilling machine (Elemental Scientific Lasers, Bozeman, MT, USA; http://www.nwrlasers.com/milling/micromill/) with a 300 um bur from Brasseler USA.
Pictured at the top is a photograph of a large black coral colony collected by Jorge Gonçalves Beijinhos (right), a fisherman of many years in the Azores. This colony is estimated to be 2800-3000 years old based on the measured rates from smaller colonies presented in our paper below. Pictured with Jorge and me are Marina Carreiro Silva, Andreia Braga Henriques and Valentina de Matos of IMAR - Instituto do Mar - Institute of Marine Research.
Photograph of a living black coral colony taken from a submersible on one of the seamounts of the Azores.
