Tintinnina (Ciliophora) and Foraminifera in plankton of hypersaline Lagoon Bardawil (Egypt): spatial and temporal variability

摘要

Lagoon Bardawil, belonging to the few hypersaline lagoons in the Mediterranean Sea, is located in the middle of the Sinai coast. Composition, distribution, and seasonal dynamics of large planktonic tintinnids and foraminifera at 12 stations in the lagoon were studied in 2009 and 2010. Fifteen species of Ciliophora (Tintinnina) and two species of Foraminifera were identified. The occurrence of different species varied greatly in the study period: two species were found in 42% to 49% of all samples, two species in 21% to 23%, 4 species in 10% to 20%, and 10 species in 1% to 5%. Only three species were found throughout the year. The average total number of all recorded protozoa varied from 2333 ind./m$^3$ (spring) to 13,733 ind./m$^3$ (winter): Tintinnina from 1250 ind./m$^3$ (spring) to 12,867 ind./m$^3$ (winter) and Foraminifera from 200 ind./m$^3$ (autumn) to 1083 ind./m$^3$ (spring). The distribution of total abundance of tintinnids and foraminifers in the lagoon area was close to random in summer and spring; during autumn and winter, it was aggregated. Tintinnid and foraminifera studies in Lagoon Bardawil were carried out previously (1985-2010); summarizing all data, it was found that interannual differences may be explained by stochastic causes and nondirected climate fluctuations.