Abstract:

The distribution and abundance of euphausiid larvae and salps were studied based on zooplankton samples collected in 2002 and 2006 from Prydz Bay, Antarctic. Larvaes of Thysanoessa macrura and Euphausia superba mainly distributed in the north of the continental shelf. Thysanoessa macrura was more abundant with relatively wider distribution area. In the year 2006 with earlier ice retreating, higher seawater temperature and chlorophyll a level, Euphausia superba and Thysanoessa macrura presented higher abundance and older developmental stage. Euphausia crystallorophias was mainly distributed in the neritic region. In the year 2002 with serious ice conditions in the neritic region, the abundance of Euphausia crystallorophias was only 95.6ind/1000m3. In the year 2006 when polynya existed, the abundance of Euphausia crystallorophias reached to 43966.6ind/1000m3, and the population was mainly composed of metanauplius (MN) and calyptopis I (CI). Salps, mostly composed of Salpa thompsoni, had a low abundance in the Prydz Bay. In 2002, S. thompsoni was only found at one station of the north of the bay with the abundance 10ind/1000m3. In 2006, S. thompsoni was found at three stations located near continental slope and average abundance reached to 146.7ind/1000m3. The research suggested that the distribution and abundance of euphausiid larvae and salps have good accordance with the environmental factors.

Key words: distribution