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Annual production to biomass (P/B) ratios of pelagic ciliates in different temperate waters

Rychert K., Kozłowska J., Krawiec K., Czychewicz N., Pączkowska M., Wielgat-Rychert M.

Oceanological and Hydrobiological Studies

2016

Vol. 45, No. 3

388--404

In aquatic environments, ciliates integrate the energy flowing through bacteria, smaller protozoa, and the prevailing fraction of algae and are further grazed upon by metazooplankton. Ciliates are incorporated into budgets and models describing ecosystem functioning. However, data for the parameterization and validation of models remain insufficient. In this study, annual production to biomass (P/B) ratios of pelagic ciliates were estimated in four lakes of different trophic status and at two sites located in the coastal zone of the Baltic Sea. All study sites were located in the temperate zone. The calculations were based on bulk data reflecting seasonal changes in ciliate production, which was estimated using an allometric equation. The annual ciliate P/B ratio for surface waters was 308 ± 81 yr-1 (mean ± standard deviation). There was no statistically significant relationship between the mean annual ciliate biomass in particular water bodies and the annual P/B ratio. In the near-bottom waters, the annual P/B ratio was 78 ± 39 yr-1. Because of the possible food limitation of ciliate growth and reconstructions of the community due to changes in environmental conditions, the ciliate P/B ratio applied in models of temperate waters should range from 50% to 100% of the P/B ratios estimated in this study.

Variations in organic matter bound in fluffy layer suspended matter from the Pomeranian Bay (Baltic Sea)

Pazdro K., Staniszewski A., Bełdowski J., Emeis K. C., Leipe T., Pempkowiak J.

Oceanologia

2001

No. 43 (4)

405-420

Fluffy layer suspended matter (FLSM) and surface sediment samples from the Pomeranian Bay were examined for fatty acid, lipid and organic matter contents. FLSM is a several-centimetre-thick layer of fairly concentrated particulate matter lying on the sea floor significantly affecting the flux of matter to depositional basins. Analyses of fatty acids were used to establish sources and decomposition rates of labile organic matter along a transect from the shallow, highly dynamic, Odra estuary to the Arkona Basin, a deep, low energy, depositional area. In FLSM and sediments respectively, the ranges of organic matter contents were 4.0-25.0% and 5.1-23.0%, those of lipids 0.1-5.4% and 0.30-1.67%, and those of fatty acids 50-991 žg g-1 dry wt. and 100-546 žg g-1 dry wt. In shallow waters, the contents of these compounds are very variable, mirroring variations in biological activity and hydrological conditions. The high percentage of polyunsaturated fatty acids in shallow areas indicates the presence of fresh, undegraded, labile organic matter of autochthonous origin. Fatty acids, the most labile components, are transported as suspended matter attached to minerals and finally accumulated in the depositional area in the form of condensed organic macromolecules. The intensity of bacterial decomposition of organic matter in this system is reflected in the high percentage of branched fatty acids. The low fatty acid content in the organic matter is attributed to the high rate of decomposition of the labile organic matter. No linear correlation was found between the contents of fatty acids and lipids.