Modal analysis of the deep-water solitary scleractinian, Desmophyllum dianthus, on SW Pacific seamounts: inferred recruitment periodicity, growth, and mortality rates

• Published in: Coral Reefs
• Main Authors: Thresher, R. E., Adkins, J., Thiagarajan, N.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer 2011
• Subjects: Demography; Deep-sea; Scleractinia; Modal analysis; Holocene; Southern Ocean
• Online Access: https://doi.org/10.1007/s00338-011-0806-7

Little is known about the demography of corals inhabiting deep-sea features due to the logistical difficulties of working at the extreme depths they inhabit. To obtain basic information about growth, mortality, and recruitment dynamics for such a coral, we applied modal analysis to the size frequency distributions of live-caught and sub-fossil specimens of the widely distributed solitary cup coral, Desmophyllum dianthus, collected on SW Pacific seamounts. Comparison of live-caught material collected in 1997 and 2007–2009 indicated modal progression over time and an implied maximum age of approximately 190 years, which is similar to ages determined previously for D. dianthus using radiometric techniques. A log-linear decline in the number of individuals with increasing size further implies a constant adult mortality rate, of 15.1% per annum in 1997 and 9.2% per annum in 2007–2009. The spacing of size modes in the 2007–2009 samples suggests regularly episodic recruitment events, at 22- to 32-year intervals, which may relate to periodic variability in large-scale Southern Ocean circulation. Preliminary analyses of size frequency distributions of the sub-fossil material suggest that the trophodynamics, growth, and adult mortality schedules of D. dianthus in the SW Pacific have remained basically similar throughout the Holocene. © 2011 Springer-Verlag. Received: 6 January 2011. Accepted: 19 July 2011. Published online: 3 August 2011. Communicated by Biology Editor Dr. Hugh Sweatman. We thank E. Anagnostou, A. Beck, W. Cho, A. Gagnon, K. Gowlett-Holmes, S. John, A. Kennedy, H. Kippo, N. Meckler, D. Mills, D. Staples, and A. Subhas, and the crews of the AUV ABE, the ROV Jason, RV Thomas T. Thompson, and RV Southern Surveyor for their professional assistance in the field. We particularly thank M. Haddon for his assistance with the modal analysis and comments on a draft manuscript. We also thank R. Waller, N. Bax and two anonymous referees for useful comments on the ms. Components of this work were supported by ...