HORIZONTAL PATCHINESS IN SYMPAGIC ORGANISMS OF THE ANTARCTIC FAST ICE

Patchiness in the horizontal distribution of sympagic organisms was st udied at an Antarctic coastal site during autumn. A hierarchical sampl ing design (nested ANOVA) was used to assess variation in the biota on scales from metres to kilometres. Metazoan abundance, chlorophyll con centration and salinity were measured in 54 sea ice cores. The metazoa n fauna was dominated by nauplii of the copepod Paralabidocera antarct ica (6 x 10(4) to 4 x 10(5) m(-2)). Other copepods present included St ephos longipes, Oncaea curvata, Oithona similis, Ctenocalanus citer, a nd unidentified harpacticoid copepods. Chlorophyll a concentrations we re generally much higher than values recorded at other sites at the sa me time of the year, reaching a maximum of 78 mg m(-2). Metazoan abund ances did not correlate strongly with chlorophyll or salinity. Signifi cant variability in abundance of P. antarctica and O. similis, and chl orophyll concentration occurred at the scale of kilometres, whereas sa linity and other metazoan abundances were not significantly variable a t any of the scales examined. Considerable variation was evident at sc ales of less than one metre.