Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

Synthesis and Complete Antimicrobial Characterization of CEOBACTER, an Ag-Based Nanocomposite.

The antimicrobial activity of silver nanoparticles (AgNPs) is currently used as an alternative disinfectant with diverse applications, ranging from decontamination of aquatic environments to disinfection of medical devices and instrumentation. However, incorporation of AgNPs to the environment causes collateral damage that should be avoided. In this work, a novel Ag-based nanocomposite (CEOBACTER) was successfully synthetized. It showed excellent antimicrobial properties without the spread of AgNPs into the environment. The complete CEOBACTER antimicrobial characterization protocol is presented herein. It is straightforward and reproducible and could be considered for the systematic characterization of antimicrobial nanomaterials. CEOBACTER showed minimal bactericidal concentration of 3 μg/ml, bactericidal action time of 2 hours and re-use capacity of at least five times against E. coli cultures. The bactericidal mechanism is the release of Ag ions. CEOBACTER displays potent bactericidal properties, long lifetime, high stability and re-use capacity, and it does not dissolve in the solution. These characteristics point to its potential use as a bactericidal agent for decontamination of aqueous environments

Histogram for the Ag nanoparticles size (A) and high-resolution Ag 3d (B) and O 1s (C) XPS spectra of the CEOBACTER.

<p>Solid line curve correspond to full multi-Gaussian fit, and dash-dot line curves show the deconvoluted signals.</p

AgNPs-ion release is sufficient to exert a bactericidal effect over <i>E</i>. <i>coli</i> cultures.

<p>By dialysis experiments, confined bacteria was killed by ions released from CEOBACTER (A). No release of AgNPs were shown in culture media inside and outside dialysis sacks (B). Ag ions was measured by ICP analysis. Free colloidal AgNPs at reported concentrations were used as a sensitivity control.</p

Bactericidal parameters (expressed as μg/ml) of the CEOBACTER nanocomposite compared with those of Zeolite-Ag nanocomposites and colloidal AgNPs.

<p>Bactericidal parameters (expressed as μg/ml) of the CEOBACTER nanocomposite compared with those of Zeolite-Ag nanocomposites and colloidal AgNPs.</p

XRD analysis.

<p>XRD patterns of the CEOBACTER, the Na-mordenite (NaMOR) and the standard NaMOR ICSD 68445 file [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0166205#pone.0166205.ref026" target="_blank">26</a>]. Inside, the NaMOR unit cell is shown.</p

Bacterial survival values (in percentage) for different CEOBACTER concentrations at increasing number of inoculums.

<p>Bacterial survival values (in percentage) for different CEOBACTER concentrations at increasing number of inoculums.</p

Exposure time and agent concentration dependence of bactericidal effect of CEOBACTER.

<p>The values are the average of three different experiments.</p