Although we did not identify Oithona to the species level, it should be noted that most of them ‘visually’ consisted of O. simplex. Neither P. elegans nor P. aculeatus nor Oithona spp. showed significant differences in abundance between sampling periods (one-way ANOVA, p = 0.167 for P. elegans, p = 0.382 for P. aculeatus and p = 0.069 for Oithona spp.) and appeared throughout the year