Accumulation of Heavy Metals in Zooplanktons from Iraqi National Waters

Abstract

Samples of zooplankton's were collected by special net from 8 sites within Iraqi national waters represented by stations: 1- Shatt Al-Basrah cannal, 2- Khour Al-Zubair, 3- Buoy 29, 4-Buoy 13, 5-Buoy 5, 6-Al-Musab, 7- Ras Al-Bisha, and 8-Al-Fao. Samplings were conducted during the period June 2009 and Feb. 2010. Zooplankton's were classified in groups: Copepods, Rofifera, Cirriped larvea, and some other minor species. Major abundant zooplankton's were Copepods, Rotifera, Cirriped larvea, Polychates, and Bivalves, while other zooplankton's which appear in minor abundance were Appendicularea, Castropod, Forminilifora, and Megalopa. Selected heavy metals Cd, Co, Cu, Fe, Hg, Ni, Pb, U, and Zn were determined in the collected samples by adopting a highly sophisticated ICP/MS at Maxxan Analytical Inc., Canada. Levels estimated of heavy metals in µg/g were high for most of studied metals due to two main reasons: 1- the marine vessels sank in the water ways, and 2- discharging of waste water from Basrah City and certain industrial estate around. Trend of descanding concentrations of heavy metals accumulated in zooplankton's at southern Iraqi Waters were in the order: Fe> Zn> U > Cu > Co > Pb > Cd > Hg. Highest levels in µg/g for toxic heavy metals Co (1.91±6.62), Hg (0.40±1.100), Ni (15.52±40.15), Pb (1.013±2.030), and U (88.6±156.55), were reported at site 7 the Ras Al-Bishah station at the top of the Northern West Arabian Gulf due to waste discharge from the Iranian idustrial estate.