Carl Zimmer, The Loom-blog author,  writes in the New York Times:

Last year the journal Nature reported an alarming increase in the number of retractions of scientific papers — a tenfold rise in the previous decade, to more than 300 a year across the scientific literature. 

This article got corrected post published saying that fraud was not no.1- motivation for retracting an article but misconduct:

The earlier version also misstated the reason cited in the study for three-quarters of the retractions for which researchers could determine the cause. It was misconduct, not fraud. (Fraud or suspected fraud accounted for 41.3 percent of retractions; other forms of misconduct made up the rest.)

The New York Times.