My first Deep-Sea Coral study
Age and growth of Red Tree Coral from Alaska
Biology of cold water corals - Published 2002
Age and growth and radiometric age validation of a deep-sea, habitat-forming gorgonian (Primnoa resedaeformis) from the Gulf of Alaska.
Sustainable fisheries require (1) viable stock populations with appropriate harvest limits and (2) appropriate habitat for fish to survive, forage, seek refuge, grow and reproduce. Some deep-water habitats, such as those formed by deep-water stands of coral, may be vulnerable to fishing disturbance. The rate at which habitat can be restored is a critical aspect of fishery management. The purpose of this study was to characterize growth rates for a habitat-forming deep-sea coral. Two nearly complete colonies of red tree coral (Primnoa resedaeformis) collected from waters off southeast Alaska were used for an analysis of age and growth characteristics. CAT scans revealed that colonies consisted of multiple settlement events, where older basal structures provided for settlement of new colonies. The decay of 210Pb over the length of the colony was used to validate age estimates from growth ring counts. Age estimates were over 100 yr for sections near the heavily calcified base. Based on validated growth ring counts, growth of red tree coral ranged from 1.60 to 2.32 cm per year in height and was approximately 0.36 mm per year in diameter. These growth rates suggest that the fishery habitat created by red tree coral is extremely vulnerable to bottom fishing activities and may take over 100 years to recover.
NOTE: Since the time of publication, red tree coral from the eastern North Pacific Ocean has been reclassified as Primnoa pacifica (Kinoshita 1907) from western North Pacific descriptions.
Andrews, A.H., Cordes, E., Mahoney, M.M., Munk, K., Coale, K.H., Cailliet, G.M., and Heifetz, J. 2002. Age and growth and radiometric age validation of a deep-sea, habitat-forming gorgonian (Primnoa resedaeformis) from the Gulf of Alaska. In: Biology of cold water corals. Eds: L. Watling and M. Risk. Special issue of Hydrobiologia. 471: 101-110
Above is Figure 3 from the publication showing the full coral colony (provided by Dave Sommerton, NOAA-AFSC) and the aged sections taken from the colony at the locations noted. The growth zone counting matched the lead-210 dating and validated the age and growth of this species.
