COMPARISON BETWEEN DIFFERENT ZOOPLANKTON SAMPLING EQUIPMENT BASED ON BERING SEA DATA

On the base of the simultaneous zooplankton catchs by the 30-litres bo ttles and 2 types of plankton nets a comparison of their catchability was done. An Ocean Judey Net (OJN) with net opening square 0.5 m(2) an d mesh size 180 mu m; and Big Judey Net (BJN) with net opening square 0.1 m(2) and mesh size 180 mu m were used. The water samples from the bottles were filtered through the net with mesh size 64 m mu m. The ca tchability of the sampling equipment was examined concerning the follo wing groups of animals: nanofagous (<1 mm), small eurifagous (1 - 3 mm ), small carnivorous (1 - 3 mm), large eurifagous (>3 mm) and large ca rnivorous (>3 mm). The abundance of the small animals (nanofagous and small carnivorous) catched by bottles is almost uncomparable with the one obtained by nets (the abundance in bottles is 1.5 - 2 orders of ma gnitude higher). The abundance of both small and large eurifagous in O JN is not far from the one in bottle catches, while in BJN it is 2 - 3 times lower. There were almost no large carnivorous in the bottles, a nd in BJN their number was 3 times lower than in OJN; their average we ight in BJN was twice lower than in OJN. The ratio of mesozooplankton catches by bottles and by two types of nets significantly decreased wi th the growth of animals size.