Vertical distribution and seasonal variation in ice algae biomass in coastal sea ice off Zhongshan Station， East Antarctica

何剑锋，陈波ＶｅｒｔｉｃａｌｄｉｓｔｒｉｂｕｔｉｏｎａｎｄｓｅａｓｏｎａｌｖａｒｉａｔｉｏｎｉｎｉｃｅａｌｇａｅｂｉｏｍａｓｓｉｎｃｏａｓｔａｌｓｅａｉｃｅｏｆｆＺｈｏｎｇｓｈａｎＳｔａｔｉｏｎ，ＥａｓｔＡｎｔａｒｃｔｉｃａ￥Ｈｅｊｉａｎｆｅｎｇａｎ...

Vertical distribution and seasonal variation in ice algae biomass in coastal sea ice off Zhongshan Station, East Antarctica

the biomass of ice algal communities in coastal sea ice off zhongshan Station, antarctica were monitored from april to december 1992. The maximum Thickness of ice cover was 1. 74 m in november/december and covered-snow was less than35 cm in depth throughout the study period. Brown layers occurred in 2～5 cm of theIce bottom in late april and november, with chlorophyll a peak values of 360. 7 and2810 mg/m3 respectively. The integrated chlorophyll a values ranged from 1. 17 to59. 7 mg/m2 with the peak occurring in november when ice algae bloomed, and theValues never exceeded 6 mg/m2 before mid october except at one site, the highest valueOccurred in april and then decreased nuctuatedly throughout the year. The biomassWas concentrated mainly in the bottom of the ice, and might be also partly concentratedIn the interior sections where autumn bloom had occurred. The dominant diatoms wereComposed of nitzschia lecointei, n. Barkleyi, n. Cylindrus in austral autumn and Amphiphiprora kjellmanii, berkeleya rutilans, nitzschia lecointei in austral spring, andShowed some difference at sites owing to the environmental conditions.