Aquatic macrophytes and benthos are unchangeable biological filters and they carry out purification of the water bodies by accumulating dissolved metals and toxins in their tissues. In view of their potential to entrap several toxic heavy metals, 3 groups of benthos and 6 macrophytes (submerged species: Potamogeton pectinatus, Ceratophyllum demersum and Najas armata); (floating species: Lemna gibba and Eichhornia crassipes root and shoot) and (emergent species: Phragmites australis shoot) were collected from 15 different locations on Lake Burullus and analyzed for determination of 6 heavy metals (Fe, Zn, Ni, Cu, Pb and Cd) contenets.  The study was aimed at understanding the importance of these benthos and macrophytes in accumulation of toxic metals and suggesting preservation and restoration of Lake Burullus ecosystem. The distribution of the investigated metals in water, sediments, benthos and aquatic plants of the lake showed that, the eastern and eastern southern parts of the lake have generally higher concentrations of heavy metals than the western and middle one. Potamogeton pectinatus showed high contents of Pb, Cd and Zn respectively. On the other hands Eichhornia crassipes showed high level of copper while in Ceratophyllum demersum high concentration of Iron was detected. The present study reveals that the aquatic macrophytes and benthos play a very significant role in removing of the different metals from the aquatic environments and they probably reduced the effect of high concentrations of these metals on the lake ecosystem. Bioaccumulation factor values showed that the trend of accumulation of most metals in the benthos was as follows: Mullusca > Arthropoda > Annelida > and in aquatic plants as: Lemna gibba> Potamogeton pectinatus > Ceratophyllum demersum > Eichhornia crassipes Root > Najas armata>phragmites australis shoot> Eichhornia crassipes shoot, which make them suitable candidates to be used in biomonitoring surveys as  a good tools for heavy metal pollution markers, in the biological treatment of the polluted water and in sustainable development of  Lake Burullus.

 

Key words: Biofilter, bioaccumulation, sustainable developments, biological treatment, macro benthos, aquatic plants, sustainable management.