Desiccation Resistance of Intertidal and Subtidal Algae

Abstract

A comparative study of various species of marine algae [Ecklonia radiata, Durvillea antarctica, Codium fragile novae-zelandiae, Hormosira banksii, C. fragile tomentosoides, Pachymenia himantophora, Carpophyllum maschalocarpum, Cystophora retroflexa, Tylotus proliferus, Gigartina alveata, Scytothamnus australis, Sargassum sinclairii and Porphyra columbina] indicates that under standard evapo-transpiration conditions the rate of dehydration is determined primarily by the ratio of evaporating surface area to volume of the organs and to a lesser extent by the water content. Factors such as mucilage content and cell wall thickness do not appear to contribute to species differences in desiccation resistance. The relationship between moisture content and tissue water potential varies with species and is a contributing factor to desiccation resistance only at high levels of water loss. There is no clear relationship between rate of dehydration of different species under standard conditions and their bathymetric position.