ORGANISM INCORPORATION INTO NEWLY FORMING ARCTIC SEA-ICE IN THE GREENLAND SEA

New ice formation, protist incorporation and enrichment in different s tages of young Arctic sea ice (grease, nilas and pancake ice) were stu died in the Greenlanc Sea in autumn 1995. Nutrients (nitrite, nitrate, phosphate and silicate), salinity and abundance estimates of organism s were analysed from surface water and new ice samples. The abundances of bacteria, diatoms, and photo-and heterotrophic flagellates in the ice and water column were determined using epifluorescence microscopy. An enrichment index was calculated to compare the abundance of organi sms in the water column with different stages of young sea ice. The re sults clearly show that (i) protist incorporation already begins durin g the first stages of new sea ice formation, (ii) incorporation of pro tists is selective, showing preference for diatoms with a relatively l arge cell size and (iii) enrichment of organisms, in particular diatom s, takes place in young sea ice in the Greenland Sea. The selectivity df the incorporation process and the evident preference for diatoms ar e presumably a result of the larger cell size and/or certain propertie s of the cell surface (e.g. stickiness) that enhance their incorporati on. The calculated enrichment indices were relatively low for bacteria and flagellates.