During the SIBEX1' programme in December 1983/January 1984, 27 hauls were made from the "Profesor Siedlecki" with a 368 — mesh midwater sampling trwal. A total of 13 fish species at postlarval or juvenile stages was found in the catches. The greatest aboundance and species diversity of juvenile ichthyofauna was observed within shelf waters of the Peninsula. Postlarval and juvenile Pleuragramma antarcticum was the most common and most aboundant species there.
In pelagic catches of the Polish BIOMASS III Expedition 24 fish species belonging to 6 families were encountered. Pleuragramma antarcticum, Electrona antarctica and Protomyctophum bolini dominated in the Bransfield Strait. Pagothenia brachysoma was abundant in the region of Elephant Island. The presence of juvenile Channichthyidae was recorded in this area only in January. In comparison with observations in other seasons an increased frequency of Chaenodraco wilsoni and decreased frequency of Chaenocephalus aceratus was noted.