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

• Published in: Journal of phycology Vol. 33; no. 4; pp. 585 - 595
• Main Authors: Stoecker, Diane K., Gustafson, Daniel E., Merrell, Jeffrey R., Black, Megan M. D., Baier, Christine T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.1997
• Subjects: archaeomonads; Brackish; brine; Chrysophyta; chrysophytes; cryotolerant; cysts; dinoflagellates; Dinophyta; halotolerant; ice algae; Key index words: Antarctica; Marine; McMurdo Sound; sea-ice; statocysts; stomatocysts; PSE, Antarctica, Victoria Land, McMurdo Sound
• ISSN: 0022-3646; 1529-8817
• DOI: 10.1111/j.0022-3646.1997.00585.x

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 secondyear land-fast sea-ice exposed to temperatures of -20 degree C or lower. In early November, when temperatures in the upper ice are <-8 degree 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 degree C, at brine salinities as high as 129 psu, and at average photon flux densities as low as 5 mu mol photons super(.)m super(-2) super(.)s super(-1). Dinoflagellate densities were >10 super(6) vegetative cells super(.)L super(-1) of ice while temperatures in the upper ice were between -6.8 and -5.8 degree C and brine salinities were similar to 100 psu. Chrysophyte densities reached >10 super(6) super(.)L super(-1) of ice by early December. High densities of physiologically active cryo- and halotolerant algae can occur in the upper land-fast sea-ice under extreme conditions of temperature and salinity.