Algal communities play a crucial role in aquatic food webs by facilitating the transfer of essential trace
elements and toxic compounds for a wide variety of organisms even to high trophic levels. Economically, algae
can be utilized for the removal of heavy metals from industrial wastewater or other sources. In the present study,
the toxicity and the ability of Nannochloropsis oculata (Heterokonta) to accumulate copper metal was
investigated. N. oculata was cultured in f/ -enriched sea water medium, which was supplemented with 0.04 ìM 2
(control), 0.10, 0.20, 0.30 and 0.40 ìM Cu+2 and harvested after 3, 6, 9, 12 and 15 days. Changes in cell numbers;
specific growth rate; chlorophyll-a concentration; copper accumulations and changes in algal cell ultra structure
were monitored. Results revealed significant (P=0.05) decreases in cell numbers; growth rate and chlorophyll-a
content with increasing exposure time and concentration. There were significant (P#0.05) increases in the
accumulation of metal levels in algal tissue when the exposure time and concentration increased. The toxicity
symptoms of Cu+2 were shown on N. oculata in the form of deformation and damage, disintegrated cell wall and
death. It can be concluded that N. oculata is able to bind the copper in the culture media.