The 96-h LC50 of H2S was higher at lower pH and toxic concentrations
ranged from 0.063 to 0.342 mg l_ 1 for Penaeus indicus and from 0.077 to 0.378
mg l_ 1 for M. dobsoni. Sulfide also inhibits nitrification (Joye and Hollibaugh, 1995) and
will, thus, lead to an increase of ammonium in the pond.