TY - JOUR T1 - Environmental Impact on Harmful Species Pseudo-nitzschia spp. and Phaeocystis globosa Phenology and Niche A1 - Karasiewicz,Stephane A1 - Lefebvre,Alain AD - IFREMER-Laboratoire Environnement Ressources de Boulogne-sur-Mer (PDG-ODE-LITTORAL-LERBL) Centre Manche Mer du Nord, 150 Quai Gambetta, 62200 Boulogne-sur-Mer, France UR - https://archimer.ifremer.fr/doc/00748/86005/ DO - 10.3390/jmse10020174 KW - REPHY KW - SRN monitoring KW - spatial-temporal analysis KW - satellite data KW - biodiversity N2 - Global environmental change modifies the phytoplankton community, which leads to variations in their phenology and potentially causes a temporal mismatch between primary producers and consumers. In parallel, phytoplankton community change can favor the appearance of harmful species, which makes the understanding of the mechanisms involved in structuring phytoplankton ecological niches paramount for preventing future risk. In this study, we aimed to assess for the first time the relationship between environmental conditions, phenology and niche ecology of harmful species Phaeocystis globosa and the complex Pseudo-nitzschia along the French coast of the eastern English Channel. A new method of bloom detection within a time-series was developed, which allowed the characterization of 363 blooms by 22 phenological variables over 11 stations from 1998 to 2019. The pairwise quantification of asymmetric dependencies between the phenological variables revealed the implication of different mechanisms, common and distinct between the taxa studied. A PERMANOVA helped to reveal the importance of seasonal change in the environmental and community variables. The Outlying Mean and the Within Outlying Mean indexes allowed us to position the harmful taxa niche among the rest of community and quantify how their respective phenology impacted the dynamic of their subniches. We also discussed the possible hypothesis involved and the perspective of predictive models. Y1 - 2022/02 PB - MDPI AG JF - Journal Of Marine Science And Engineering SN - 2077-1312 VL - 10 IS - 2 ID - 86005 ER -