Periodograms of environmental parameters.

<p>Lomb-Scargle periodograms for: a) and b) flow magnitude in June and July respectively, c) chlorophyll concentration in December and finally, d) oxygen concentration in December. The horizontal dashed lines indicate significance for α = 0.05. The <i>p values</i> correspond to the peak in each periodogram (i.e. red, vertical dashed lines).</p

Photos of the studied species.

<p>The three species studied, as recorded by Wally in transects at the hydrates site; a) <i>A</i>. <i>fimbria</i> b) <i>E</i>. <i>stoutii</i> and c) juvenile crab. The same scale bar applies to all 3 plates.</p

Photos of the studied species.

<p>The three species studied, as recorded by Wally in transects at the hydrates site; a) <i>A</i>. <i>fimbria</i> b) <i>E</i>. <i>stoutii</i> and c) juvenile crab. The same scale bar applies to all 3 plates.</p

Map of the study site.

<p>The position of the gas hydrates site in Barkley Canyon, off Vancouver Island, and the path followed by Wally when the linear transects were performed (i.e. between waypoints 16–10). Canyon map modified from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163808#pone.0163808.ref034" target="_blank">34</a>]. Transect representation modified from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163808#pone.0163808.ref014" target="_blank">14</a>].</p

Periodograms of environmental parameters.

<p>Lomb-Scargle periodograms for: a) and b) flow magnitude in June and July respectively, c) chlorophyll concentration in December and finally, d) oxygen concentration in December. The horizontal dashed lines indicate significance for α = 0.05. The <i>p values</i> correspond to the peak in each periodogram (i.e. red, vertical dashed lines).</p

Species life habits (i.e. SW for swimmer, WL for walker, NKB for nektobenthic, ENB for endobenthic and EPB for epibenthic) in relation to their mode of displacement, the summary of their periodic activity (i.e. D for diurnal, C for crepuscular and N for nocturnal) and the most important environmental variables that regulate it.

<p>Species life habits (i.e. SW for swimmer, WL for walker, NKB for nektobenthic, ENB for endobenthic and EPB for epibenthic) in relation to their mode of displacement, the summary of their periodic activity (i.e. D for diurnal, C for crepuscular and N for nocturnal) and the most important environmental variables that regulate it.</p

Redundancy Analysis (RDA) of the hydrates benthic community.

<p>RDA biplots for each one of the three months of the study period; a) June, b) July and c) December. The direction and length of the blue vectors depicting environmental variables represent positive or negative correlation with the ordination and proportionality of correlation respectively. Their biplot scores are depicted on the blue axes (normalized range -1 to 1). The scores for sites and species are weighted for scaling reasons and depicted on the black axes.</p

Waveform analyses of concomitant biological and environmental data.

<p>Waveforms of animal counts (black, 4 h sampling frequency) as the average (±sd) of the 5 days sampling period and of environmental parameters (red, hourly); a) and b) <i>A</i>. <i>fimbria</i> in June and July respectively, c) <i>E</i>. <i>stoutii</i> in December and finally, d) juvenile crabs in December. Note the difference in scale among different species. The dashed horizontal lines correspond to the MESOR. Shaded parts represent the approximate night duration at the time of the study. <i>X axis</i> values correspond to local time (PST).</p

Supplementary video 5_data 3 time lapse_POD1_canyon axis

Time-lapse video assembled with data from the 675 kHz Kongsberg imaging rotary sonars. Dataset 3: (April 11-23, 2011 - Canyon Axis). Please refer to the ‘Readme’ file, or to the ‘Supplementary Materials’ file available through Nature Scientific Reports, for complete description of the sampling protocol

Supplementary video 1_data 1 time lapse_POD1_canyon axis

Time-lapse video assembled with data from the 675 kHz Kongsberg imaging rotary sonars. Dataset 1: (Nov 19-29, 2010 - Canyon Axis). Please refer to the ‘Readme’ file, or to the ‘Supplementary Materials’ file available through Nature Scientific Reports, for complete description of the sampling protocol