146 Methodological Problems of Marine Macroalgae Age Estimation

• Published in: Journal of Phycology
• Main Author: Selivanova, O. N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2003
• Subjects: Kamchatka
• Online Access: http://dx.doi.org/10.1111/j.0022-3646.2003.03906001_146.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-3646.2003.03906001_146.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-3646.2003.03906001_146.x

To know the birthdate of any organism is the best way to estimate its age. Unfortunately direct chronometric method, being the most reliable, can't be generally applied. In these cases indirect methods are used. One of them – morphobiometric – is used to estimate age of trees by the number of year rings in the stem or fucoid algae by the number of dichotomic branching. Both methods are widely used however the data obtained may deviate considerably from the true age of the plants. In this study I compared chronometric data on algal age to those obtained by calculation of the number of dichotomic branching in Fucus evenescens growing in Kamchatka, Russia. Field experiments were carried out from 1999 to 2002. No marked with plastic lables plants survived for 3 years. The comparison showed that morphobiometric data exceeded true age of algae at least in 2–3, sometimes even in 5 times. The first year plants can produce up to 5 dichotomous branching per season and can become fertile in the first months of their life. There is information in Russian literature that Kamchatka's F. evenescens age can reach 12–15 years. I consider these data erroneous and suppose underestimation of the number of branches in the early stages of Fucus development to be the cause of overestimation of its true age. In my opinion it is not more than 4–5 years. Application of morphobiometric method is more problematic in case of polytomy. Besides that this method usually causes damage or death of the plant. So I consider that only chronometric method can give the researcher exact information on the age of macroalgae.