Research note: Salinity tolerance of Arctic kelps from Spitsbergen

Abstract

SUMMARYThe effect of hypo‐ and hypersaline treatments on the effective quantum yield of photosystem II was comparatively studied with a pulse amplitude modulated fluorometer (PAM) in the brown algal speciesAlaria esculenta,Fucus distichus, Laminaria digitata,Laminaria solidungula,Saccharina latissima(formerlyLaminaria saccharina) andSaccorhiza dermatodeacollected in the Arctic Kongsfjorden (Spitsbergen). While the euryhalineF. distichuswas not affected at all by salinities ranging from 5 to 60 psu,A. esculenta, S. latissimaandL. solidungulaexhibited under hyposaline conditions strong loss of pigments (bleaching) or even high mortality reflecting stenohaline features. In contrast to the latter species,L. digitataandS. dermatodeasurvived all salinities, but showed reduced photosynthetic activities at the lowest and highest salt treatments and hence, can be characterized as stenohaline‐euryhaline organisms. The data are discussed in terms of vertical zonation (eulittoral versus sublittoral habitat), in terms of interactive effects with other abiotic factors such as temperature and in terms of the species‐specific acclimation potential.