Aquatic toxicity tests of<i>Ulva pertusa</i>Kjellman (Ulvales, Chlorophyta) using spore germination and gametophyte growth

Abstract

Aquatic toxicity tests using spore germination and gametophyte growth of the green alga, Ulva pertusa Kjellman, were developed and evaluated by assessing the toxicity of different organic and inorganic chemicals and elutriates of sewage or waste sludge. The toxic ranking of three metals was: Cu (EC50 of 0.017mg l -1)>Zn (0.378mgl -1)> Cd (0.789 mgl -1) for spore germination and Cu (0.023-0.027mg l -1)> Cd (0.189-0.200mg l -1)> Zn (0.307-0.317 mgl -1) for gametophyte growth. Spore germination (EC50 of 3.95mg l -1) was more sensitive to formalin than gametophyte growth (6.92-7.18mg l -1). The EC50 for tributyltin oxide differed between the endpoints, with values of 0.586mg l 1 for germination and 0.391-0.396mg l 1 for growth responses. After exposure to three different sludge elutriates the greatest and least toxic effects were found for urban sewage (7.6-8.3%) and filtration bed (>61%), respectively. The bioassays are simple, inexpensive, eco-relevant and have a potential application worldwide. © 2009 British Phycological Society.