Statistical analyses
Median lethal concentration (LC50) values were
calculated for all filtrates using an appropriate method
of analysis based on attributes of the data (e.g.
Spearmann–Karber or Probit; US EPA, 2002). Median
lethal time-to-death (LT50) values were estimated using
the Trimmed Spearmann–Karber method (US EPA,
2002). Regression analyses were performed in
SigmaPlot (Version 11).