Melting sea ice for taxonomic analysis: a comparison of four melting procedures

The influence of four melting procedures on the taxonomic composition of the sea-ice algal community in Kobbefjord, south-west Greenland, was investigated in April 2008. Direct melting (at 4 and 20 degrees C) was compared with melting in buffering seawater (with salinities of 10 and 30). The sea-ice algal community consisted of diatoms, cysts and several flagellate groups. Direct melting at 20 degrees C differed significantly from one or more of the other melting procedures regarding the flagellate groups chrysophytes, chlorophytes, dinoflagellates and unidentified flagellates, whereas diatom, cyst and cryptophyte abundance was similar, regardless of the melting procedure. Apart from chrysophytes, the three other melting procedures (direct melting at 4 degrees C and buffered in seawater with salinities of 10 and 30) were not statistically different. It is recommended that direct melting at 20 degrees C is avoided, whereas the three slow melting procedures are all comparable. This will enable the future comparison of data from a wide geographic and historical range, thereby increasing our knowledge of sympagic algal communities.