  Censored data are seldom taken into account in Species Sensitivity
Distribution (SSD) analysis. However, they are found in virtually every dataset
and sometimes represent the better part of the data. Stringent recommendations
on data quality often lead to discard a lot of this meaningful data, often
resulting in datasets of reduced size, which lack representativeness of any
realistic community. However, it is reasonably simple to include censored data
into SSD by using an extension of the standard maximum likelihood method. In
this paper, we detail this approach based on the use of the R-package
\emph{fitdistrplus}, dedicated to the fit of parametric probability
distributions. In particular, we introduce the new web-tool MOSAIC$\_$SSD to
fit an SSD on datasets containing any kind of data, censored or not.
MOSAIC$\_$SSD allows predicting any Hazardous Concentration (HC) and provides
in addition bootstrap confidence intervals on the prediction. In the end,
taking examples from published data, we illustrate the added value of including
censored data in SSD.
