“…Several studies have failed to correlate diatom abundance with copepod reproductive failure (Irigoien et al, 2002(Irigoien et al, , 2005Koski, 2007) whereas other studies have reported a strong correlation (Ask et al, 2006;Halsband-Lenk et al, 2005;Horner et al, 2005;Ianora et al, 2004;Leising et al, 2005aLeising et al, , 2005bMiralto et al, 1999;Pierson et al, 2005;Vargas et al, 2006). Several field (Jó nasdó ttir et al, 2011;Poulet et al, 2006;Wichard et al, 2008) and mesocosm investigations (Carsten et al, 2012;Gerecht et al, 2013;Koski et al, 2012;Vidoudez et al, 2011b) have also failed to correlate the quantity of PUAs produced with copepod egg production and/or hatching success. These contradictory results may reflect speciesspecific or strain-to-strain (Gerecht et al, 2011) differences in the production of PUAs, clone variability in production levels during the course of a bloom (Taylor et al, 2009) or in different years (Gerecht et al, 2011), unbalanced physiology due, for example, to nutrient-limited growth (Ribalet et al, 2009) or to the capability of some predators to detoxify these compounds or to activate defense systems against them (Lauritano et al, 2011(Lauritano et al, , 2012.…”