Variations in F_v/F_m and <i>p</i> values derived from FIRe after 48 hrs of incubation.

<p>Data shown are the means ± S.E. * indicate significant difference compared with the control group.</p

Hydrographic features of the water column immediately prior to the start of each bioassay (BA).

<p>Water column profiles were measured with calibrated sensors attached to the CTD rosette. At station A and station B in April (BA1 and BA2) and August (BA3 and BA4). The lack of PAR in BA1 was because the bioassay was started at night. The low PAR in BA4 was due to extensive cloud cover.</p

Phytoplankton community compositions in different treatments in the four bioassays at t = 48 hours determined by ChemTax V 1.95.

<p>NG: no grazers, SB: surface+bottom.</p

Variations in F_o values in measured in the different treatments.

<p>Data shown are the means ± S.E.. * indicates significant difference compared with the ‘control’ at the same time point. NG: no grazers, SB: surface+bottom. Unlike chl <i>a</i> which was measured only at the beginning (t = 0) and end (t = 48 hours), samples for fluorescence parameters were measured at t = 0, 24 and 48 hours.</p

Study area and bathymetry for the mechanisms controlling hypoxia program in the northern Gulf of Mexico.

<p>The 10, 20, 50 and 100</p

Initial pigment / chl <i>a</i> ratios for the different phytoplankton groups used for ChemTax V1.95.

<p>Diat  =  diatoms, Dino  =  dinoflagellates, Cyan  =  cyanobacteria, Crypto  =  cyptophytes, Prymn  =  prymnesiophytes, Pelago  =  pelagophytes, Prasino  =  prasinophytes, Chloro  =  chlorophytes. See text (methods) for pigment names.</p

Linear relationship between F_o and chl <i>a</i> concentration (µg L⁻¹) after 48 hrs incubation in different bioassays.

<p>R² = 0.6216, <i>p</i><0.001 in BA1, R² = 0.6202, <i>p</i><0.05 in BA2, R² = 0.3503, <i>p</i><0.01in BA3 and R² = 0.5488, <i>p</i><0.05 in BA4.</p

Average σPSII and τQA values measured in the four bioassays.

<p>Data shown are the means ± S.E. * indicate significant difference compared with the control group.</p

Different nitrate uptake related parameters in multiple marine species belonging to four eukaryotic phytoplankton groups, modified from Litchman et al. [20].

<p>Different nitrate uptake related parameters in multiple marine species belonging to four eukaryotic phytoplankton groups, modified from Litchman et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0088732#pone.0088732-Litchman1" target="_blank">[20]</a>.</p

Phytoplankton community compositions in April and August 2010–2012, at station A and B.

<p>Data from surface samples around noon. Samples for 2011at station B in April were lost.</p