ABSTRACT: The seasonal variations of temperature, dissolved organic carbon (DOC), chlorophyll a (chl a), and bacterial and protistan abundance were investigated in an enclosed Eastern Mediterranean embayment over an 8 mo period. DOC levels in the gulf were high, likely due to allochthonous input through freshwater discharge. However, after the end of spring, when allochthonous input was minimal, bacterial abundance was linearly related to chl a and DOC, suggesting that during this period the remaining DOC pool (probably autochthonous DOC) was important. Bacterial abundance was significantly correlated with the biomass of the phytoplankton at the end of spring and throughout summer. A correspondence of protistan abundance with bacteria, especially during the warm months, when the phytoplankton biomass was low, suggests that the microbial loop is the dominant component of the food web structure during the oligotrophic period of the year.

KEY WORDS: Phytoplankton · Bacteria · Protists · Microbial loop · Coastal waters · Mediterranean

Published in AME Vol. 15, No. 3 (1998) on August 31
ISSN: 0948-3055. Copyright © Inter-Research, Oldendorf/Luhe, 1998