Morphology and Ecology of Diatoms in Sea Ice from the Weddell Sea,
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
Pagination or Media Count:
Diatom species composition and relative abundances were determined for ice cores obtained from Weddell Sea pack ice during the October-November 1981 Weddell Polynya Expedition WEPOLEX. Ice thickness and salinity indicate that the ice was less than one year old. The predominant ice type 70 was frazil, which has the capacity to mechanically incorporate biological material through nucleation and scavenging. Diatoms were found throughout the length of the cores. Species showed down-core fluctuations in abundance that appeared to be correlated with changes in ice type. Pennate forms were more abundant than centrics, the average ratio being 161. Diatom frustules with intact organic material were more abundant 5 billion cellsliter. Differences in species abundances are attributed initially to incorporation of algal cells from a temporally changing water column and subsequently to diatom reproduction within the ice. Scanning electron micrographs illustrating the morphologic characteristics of the predominant species are included.
- Biological Oceanography