Phytoplankton and Primary Production in Iraqi Marshes

Abstract

Mesopotamian marshes were once quite famous by their biodiversity and cultural richness. In fact, the area is an important stopover along the flyway of millions of migratory birds between Europe and Africa. However southern Iraqi marshes had faced a deliberate drainage by previous regime in Iraq, and there are several efforts to restore it again. Theses marshes consist of eastern, central, and southern part that is fed with different sources of water from Tigris, Euphrates, and Shatt al-Arab Rivers. The most obvious feature of algal vegetation in this area is the dominance of filamentous epiphytes with other free floating filamentous algae. Algal habitats include reed stems, lime-encrusted algal felt, and submerged parts of wood and boats. In such habitats, Chaetophora incrassata, Lyngbya, Calothrix, Aphanocapsa, Tolypothrix, and Schizothrix are found, besides heterocystous blue-green algae which are common epiphytic flora. On the other hand, diatoms are dominant followed by Cyanophyta, Chlorophyta, Cryptophyceae, Pyrrophyceae, and Euglenophyceae. Generally, there are two peaks of phytoplankton bloom that have been recorded: one in autumn and the other in June–July. Chlorophyll a concentration had shown different values at different stations; generally it ranges between 0.15 and 21.2 μg/l. The Iraqi marshes are oligotrophic-mesotrophic before 2004, while these marshes are being toward eutrophic according to chlorophyll a concentration. Almost all primary productions within marshes are originated from the role of algae and macrophytes, with slight role played by phytoplankton. Primary productivity in Mesopotamian marshes had been estimated to be between 132 and 407 mg/carbon/m3/day estimated by light and dark bottle method. It seems that there are a lot of research to be done in the future regarding the Mesopotamian marshes particularly after the re-flooding process, which the job of the scientists in the near future.