herbicide treatments zooplankton are killed by the microtubule inhibiting herbicides that do not harm the wild type algae and the cyanobacteria such as benefin butralin dinitramine ethalfluralin oryzalin pendimethalin trifluralin amiprophos methyl butamiphos dithiopyr thiazopyr propyzamide tebutam and chlorthal dimethyl algal density is significantly higher at 5 and 14 compared to ambient and 1 co 2 concentrations while zooplankton reduced algal growth at low concentrations in high co 2 there are no differences between batches with and without zooplankton indicating the inhibition of zooplankton activity zooplankton numbers remain low for 7 days after termination of co 2 treatments implying a significant long term impact adams e e j a caulfield et al 1998 u201c impacts of reduced ph from ocean co 2 disposal sensitivity of zooplankton mortality to model parameters u201d waste management 17 5 6 375 380 beale s i weinstein j d 1990 u201c biosynthesis of heme and chlorophylls u201d u201c in tetrapyrrole metabolism in photosynthetic organisms ed dailey h a mcgraw hill new york 287 391 b u00f6ger p and g sandmann 1998 u201c carotenoid biosynthesis inhibitor herbicides u2014 mode of action and resistance mechanisms u201d pesticide outlook 9 6 29 35 deng m d and j r coleman 1999 u201c ethanol synthesis by genetic engineering in cyanobacteria u201d appl environ microbiol 65 2 523 8 golden s s j brusslan et al 1987 u201c genetic engineering of the cyanobacterial chromosome u201d methods enzymol 153 215 31 gressel j and a.