Chronicles of the deep : ageing deep-sea corals in New Zealand waters

How old is a coral? Finding the answer requires some rather complex steps. We need to understand: the source of carbonate; the effects of climatic events; how to interpret growth zones; the effect of 14C and biological processes such as feeding and reproduction; and how to overcome the lack of deep-sea environmental data records. We also need to find out where on the coral we should be sampling to get the best estimates of age. At the moment we know little about how deep-sea corals deposit their calcite, but we will be exploring this further so that we can have greater confidence in our age estimates. To confirm and validate age and growth, it will be necessary to use a combination of some of the the possible methods for ageing coral. In addition to ageing the corals, this work should yield a high-resolution record of ocean temperature during the past 100 years by using stable-isotope signatures preserved in the corals' carbonate skeletons. (author). 4 figs