Frequency of occurrence (F%) by depth strata of the fast (cephalopods) and slow (elasmobranchs) life history species analysed.

<p>Numbers between brackets are the sampling size and the arrows indicate the datasets removed from the analysis (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148770#sec002" target="_blank">Material and methods</a>).</p

Outputs of the statistically significant generalized additive models (GAM) modelling cephalopod and elasmobranch densities (N km^-2) against environmental (SST, depth) and fishing effort (VMS) covariates.

<p>Model details are in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148770#pone.0148770.t002" target="_blank">Table 2</a>.</p

Map of the Balearic Islands (western Mediterranean) showing the sampling stations and the surface chlorophyll-a concentration and sea surface temperature (SST) during the sampling surveys, together with the vessel monitoring system (VMS) records of the bottom trawl fleet operating around the two major islands (Mallorca and Menorca).

<p>Map of the Balearic Islands (western Mediterranean) showing the sampling stations and the surface chlorophyll-a concentration and sea surface temperature (SST) during the sampling surveys, together with the vessel monitoring system (VMS) records of the bottom trawl fleet operating around the two major islands (Mallorca and Menorca).</p

Study area and sampling sites.

<p>Map of the western Mediterranean Sea showing 200 to 1000 m isobaths and selected stations sampled for at least 5 out of the 12 years in the MEDITS surveys. Main surface circulation patterns are described by arrows: Northern Current (NC), Balearic Current (BC), Atlantic jet (AJ) and Alboran gyres (AG).</p

Overall predicted distributions (2001–2012) of environmental and trophic covariates.

<p>A) log transformed density of benthic crustaceans (preys of octopus), B) log transformed density of meso-pelagic fish (preys of squid), C) Chlorophyll a concentration (Chla), and D) sea surface temperature (SST) estimated from variable coefficient Generalized Additive Models.</p

Spatially explicit effects of environmental and trophic covariates on the density of octopus (<i>Eledone cirrhosa</i>) and squid (<i>Illex coindetii</i>).

<p>Effects of A) prey densities, B) chlorophyll a concentration (Chla) and C) sea surface temperature (SST) estimated from variable coefficient Generalized Additive Models using only positive data. Red and blue bubbles represent respectively negative and positive effect of each covariate on log-transformed cephalopod densities. Only effects (regression slopes) significantly different from zero are showed, based on the estimates of the 95% confidence interval. Overall predicted densities (log transformed) of each species are shown underlayed, with the highest densities indicated by dark grey cells.</p

Overall predicted distributions of octopus (<i>Eledone cirrhosa</i>) and squid (<i>Illex coindetii</i>) estimated from variable coefficient Delta Generalized Additive Models.

<p>A) Spatial distribution of log transformed densities. B) Partial effects of depth on the vertical distribution of cephalopod densities. Shaded areas indicate 95% confidence intervals.</p

Study area and sampling sites.

<p>Map of the western Mediterranean Sea showing 200 to 1000 m isobaths and selected stations sampled for at least 5 out of the 12 years in the MEDITS surveys. Main surface circulation patterns are described by arrows: Northern Current (NC), Balearic Current (BC), Atlantic jet (AJ) and Alboran gyres (AG).</p

Temporal patterns of the Shannon diversity H’ at six different Mediterranean bioregions using the MEDITS sampling carried out during 1994–2012.

<p>Temporal patterns of the Shannon diversity H’ at six different Mediterranean bioregions using the MEDITS sampling carried out during 1994–2012.</p

Boxplots of Shannon diversity (A) and Species richness (B) per haul, obtained using all MEDITS samples taken during 1994–2012.

<p>Boxplots of Shannon diversity (A) and Species richness (B) per haul, obtained using all MEDITS samples taken during 1994–2012.</p