Fig 1.
Location of the sampling station.
Table 1.
Type and acquisition characteristics of the studied variables.
Fig 2.
Chlorophyll a fluorescence and daily net growth rates.
In situ Chl a fluorescence in 2015 (A) and 2016 (B) and daily net growth rates in 2015 (C) and 2016 (D), indicating daily biomass gains (positive values) and losses (negative values). The bloom periods have a green background, and the post-bloom periods and winter latency period have a white background.
Fig 3.
Main environmental variables for 2015 (left) and 2016 (right). A to H are the meteorological data: PAR (A and B), wind direction (C and D), wind speed (E and F) and air temperature (G and H); and I to N are the hydrological variables: water temperature (I and J), salinity (K and L) and turbidity (M and N). The background colors for the various periods are the same as in Fig 2.
Fig 4.
Principal component analysis (PCA) of environmental variables.
PCA of Chl a, meteorological and hydrological data for the 2015 data set (A) and 2016 data set (B). PCA allows the variables to be projected in multidimensional space to highlight the relationships between them. Here, only two dimensions are represented as they explain the environmental dynamic well. The arrows represent the variables. When arrows are far from the center and close to each other, they are positively correlated, whereas when they are symmetrically opposed, they are negatively correlated. If the arrows are orthogonal, they are not correlated. Finally, when the variables are close to the center, they are not well projected in the dimensions represented; consequently, it is hard to conclude that a relationship occurs between these variables. In this last case, to highlight masked links, we coupled the PCA with pairwise Spearman’s rank correlations as described in the Material and methods.
Table 2.
Time-lag correlations between meteorological and hydrological data.
Fig 5.
Nutrient concentrations in 2015 (left) and 2016 (right) for PO4 (A and B), Si(OH)4 (C and D), NO2 (E and F), and NO3 (G and H). The background colors for the various periods are the same as in Fig 2.
Fig 6.
Phytoplankton abundances and diversity.
Analyzed by flow cytometry for 2015 (A and C) and 2016 (B and D). Dominant taxa observed by microscopy for 2015 (E, G and I) and 2016 (F, H and J). The background colors for the various periods are the same as in Fig 2.
Table 3.
Relative contributions of the dominant phytoplankton groups to the carbon biomass and abundance.