[The influence of salinity on the rate of dark respiration and structure of the cells of brown algae thallus from the Barents sea littoral].

We studied the changes in the rate of dark respiration (DR) and structure of the cells in Ascophyllum nodosum and Fucus vesiculosus thalluses during the incubation at 40, 34, 20, 10, and 2@1000 salinity for 14 days. The changes in salinity affect the rate of DR and the structure of the thallus apical cells: the organelles swell and later are destroyed. The effect of decreased salinity on the algae was more pronounced as compared to the increase. The stress intensity directly increased with the rate of desalination. Further adaptation of the algae to low salinity enhanced DR and, hence, was an energy-dependent process. Despite higher DR rates (during the stress and adaptation) in F. vesiculosus as compared to A. nodosum, the seaweeds had similar pattern of adaptation to the changed salinity. Different primary response of the seaweeds to 20@1000 salinity was an important exception; apparently, the salinity around 20@1000 is the limit of these species distribution in desalination zones.