.
http://plosone.org/article/info:doi/10.1371/journal.pone.0021403#article1.body1.sec2.sec1.p2

For the paper [48], the SEM given in the table is mistaken. It should be 30 +- 10 instead of 30 +- 19. We apologise for this error.
Let us add that the message remains the same, also for this dataset, since the standard deviation is now 40, which is still larger than the mean.
The cited paper does not suggest that the expected number of rotifers or individual numbers could be negative. Thus, there
is no mistake committed by the authors.
Let us emphasize again that we did not mean to suggest "mistakes" for any of the papers cited (cf. the paragraph before "Towards solving the problem" on p.3) but that more efficient analyses are possible.