The pollution enhanced the negative interaction between these algal species. M. aeruginosa
outcompete C. pyrenoidosa (Fig. 1 e C2). Similarly, C. pyrenoidosa and S. obliquus displayed a competitive effect in the unpolluted
condition. Furthermore, Pb and PCBs induce a positive interaction between two green algae in the stationary and
death phases (Fig. 1 e C3).
Fig.