Abstract:
Photosynthesis at high latitudes demands efficient strategies of light utilization
to maintain algal fitness and performance. The fitness, and physiological
adaptation, of a plant or algae species depends in part on the abundance and
efficiency of the pigments it can produce to utilize the light resource from its
environment. We quantified pigment composition and concentration in six
species of the brown macroalgal genus Desmarestia, collected from sub-
Antarctic sites (Strait of Magellan, Beagle Channel Cape Horn Province) and
sites on the Antarctic Peninsula and adjacent islands. Sub-Antarctic Desmarestia
species exhibited lower concentrations of chlorophyll a, chlorophyll c and
fucoxanthin than endemic Antarctic species. Antarctic samples of D. menziesii
and D. antarctica collected along a decreasing latitudinal gradient showed
spatial and interspecific differences in light-harvesting pigment composition.
Our results suggest distinct physiological adjustments in Desmarestia species in
response to heterogeneous abiotic environmental conditions. The marine sub-
Antarctic and Antarctic ecosystems are characterized by harsh environments
(e.g., extreme irradiance, photoperiod, temperature, salinity) to which the
physiology of macroalgal species must adapt.