TY JOUR TI CHARACTERISTICS OF PHYTOPLANKTON DEVELOPMENT IN MIDDLE CASPIAN IN SUMMER PERIOD KW phytoplankton KW Middle Caspian KW diatoms KW abundance KW biomass KW saprobicity JO Vestnik of Astrakhan State Technical University. Series: Fishing industry AU Zimina T, a.. AU Ardabyeva, A.. AU Kotelnikov, A.. PY 2021 IS 2021 PB Astrakhan State Technical University