Fig 1.
Study area in the Western Mediterranean.
Hydrographic (black and red crosses) and plankton (red crosses) stations during the survey. The schematic lines indicate the main currents, Northern Current (NC) and Balearic Current (BC), and recent AW inflow through the Eivissa and Mallorca Channels. Coastline is from Natural Earth [41] and Instituto Hidrográfico de la Marina [42], and isobaths (every 400 m depth) are from European Marine Observation and Data Network (EMODnet, [43]).
Fig 2.
TS diagram of the water layer from 0 to 100 m depth.
Recent Atlantic Water (blue dots), south of 39.5°N; old Atlantic Water (green dots), north of 39.5°N.
Fig 3.
Horizontal distribution of a) salinity and b) temperature at 10 m depth from CTD data. Dots show the sampling stations. Images were created using ODV [44].
Fig 4.
Vertical distribution of a) salinity, b) temperature and c) fluorescence in the upper 100 m depth from CTD data, along the continental slope. Horizontal axis indicates latitude range. Vertical dotted lines represent 1 m binned CTD profiles data.
Fig 5.
Mean velocity field for August 2016 at 10 m depth from CMEMS reanalysis [45].
The current velocity is depicted through the colour scale and arrows show the current direction. Coastline is from Natural Earth [41] and Instituto Hidrográfico de la Marina [42].
Fig 6.
Vertical distributions of ephyrae in night time (dark grey bars) and daytime (light grey bars) and temperature (red), salinity (blue), and fluorescence (green). Data of six stations representative of the hydrographic conditions at the a) north (41.0°N, 2.0°E), b) centre (39.5°N, 0.5°E) and c) south (38.0°N, 0.2°E) of the sampling area. Ephyrae relative abundance by station. Values in parenthesis indicate ephyrae abundance 100 m-3.
Table 1.
Ephyrae abundance (mean ± standard error) by day/night and depth stratum.
Fig 7.
Horizontal distribution of P. noctiluca ephyrae overlaid on the mean a) salinity and b) temperature at 10 m depth for the sampling period from CMEMS reanalysis [45]. Coastline is from Instituto Hidrográfico de la Marina [52] and isobaths (every 400 m) are from EMODnet [43].
Fig 8.
Depth-integrated ephyrae abundances in relation to mean surface (5–10 m depth) salinity and temperature at plankton stations.