EXCYSTMENT AND GROWTH OF CHRYSOPHYTES AND DINOFLAGELLATES AT LOW TEMPERATURES AND HIGH SALINITIES IN ANTARCTIC SEA‐ICE 1

• Published in: Journal of Phycology
• Main Authors: Stoecker, Diane K., Gustafson, Daniel E., Merrell, Jeffrey R., Black, Megan M. D., Baier, Christine T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Antarc*; Antarctic; Antarctica; McMurdo Sound; Sea ice
• Online Access: http://dx.doi.org/10.1111/j.0022-3646.1997.00585.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-3646.1997.00585.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-3646.1997.00585.x

ABSTRACT Extreme environmental conditions have been thought to limit algal growth in the upper sea‐ice. In McMurdo Sound, Antarctica, chrysophyte statocysts (stomatocysts) and dinoflagellate hypnozygotes (resting cysts) overwinter in first‐ and second‐year land‐fast sea‐ice exposed to temperatures of ‐20° C or lower. In early November, when temperatures in the upper ice are < −8°C and brine salinities are >126 psu, dinoflagellate cysts activate and shortly thereafter excyst. During early November, chrysophyte statocysts also begin to excyst. Net daily primary production occurs in the sea‐ice brine at temperatures as low as −7.1° C, at brine salinities as high as 129 psu, and at average photon flux densities as low as 5 μmol photons.m −2 .s −1 . Dinoflagellate densities were >10 6 vegetative cells.L −1 of ice while temperatures in the upper ice were between −6.8 and −5.8° C and brine salinities were ∼100 psu. Chrysophyte densities reached >10 6 .L −1 of ice by early December. High densities of physiologically active clyo‐ and halotolerant algae can occur in the upper land‐fast sea‐ice under extreme conditions of temperature and salinity.