Dimethylsulphoniopropionate (DMSP) has been proposed to be a compatible (os
motic) solute in marine macro-algae, allowing adaptation to changes in the
osmotic pressure of the growth medium. However, whilst DMSP undoubtedly doe
s contribute substantially to the overall osmotic pressure of the cytoplasm
, several studies have demonstrated that its intracellular concentration is
not directly regulated by the osmotic pressure of the growth medium. Thus,
DMSP does not behave as a compatible solute sensu stricto and therefore it
s role may not be strictly osmotic.
Recently, HAMILTON & LENTON (1998) proposed that DMS emissions associated w
ith blooms of DMSP accumulating marine phytoplankton may be linked to an ae
rial mode of dispersal via the induction of cloud formation and local conve
ctive winds. Only micro-algae were discussed. All macro-algae, however, als
o have unicellular stages as gametes or spores which could become windborne
.
In this paper, we review the literature on the life histories, growth cycle
s and ecology of marine DMSP synthesising chlorophycean macro-algae, in ord
er to assess whether a similar dispersal mechanism may exist within this gr
oup. Whilst only direct experimental evidence can resolve if these macro-al
gae are dispersed or not by an aerial mechanism, many features of their gro
wth, reproductive and life cycles are consistent with such a mechanism. Suc
h an aerial dispersal mechanism might represent an especial ecological adva
ntage in this group, allowing colonisation of areas separated by land masse
s or denied to normal waterborne dispersal routes by directional currents.