<p>Box-and-whisker plot of median PMT counting rates (log scale) versus current speed classes for salinities higher (red) or lower (grey) than 38.479 for data recorded in (<b>a</b>) 2008, (<b>b</b>) 2009 and (<b>c</b>) between January and June 2010. The salinity threshold of 38.479 is used as a marker of the intrusion of newly formed deep water at the ANTARES site. While bioluminescence increases with current speed, it is also enhanced by the modification of WMDW (red box-plots). The top and bottom of each box-plot represent 75% (upper quartile) and 25% (lower quartile) of all values, respectively. The horizontal line is the median. The ends of the whiskers represent the 10<sup>th</sup> and 90<sup>th</sup> percentiles. Outliers are not represented. The statistical comparison between the two box-plots (red and grey) in each current class is given by the Kruskal-Wallis test: the observed difference between the two samples is significant beyond the 0.05 (*), the 0.01 (**) and the 0.001 (***) levels. The absence of an asterisk in some current classes indicates that the difference between the two box-plots is not significant. The number of measurements for salinity lower or higher than 38.479 is given in black or in red, respectively. Note the different scales of figures a, b and c.</p
