<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=utf-8">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Helvetica;
panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Roboto;
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
h1
{mso-style-priority:9;
mso-style-link:"Título 1 Car";
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:24.0pt;
font-family:"Times New Roman","serif";
font-weight:bold;}
h2
{mso-style-priority:9;
mso-style-link:"Título 2 Car";
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:18.0pt;
font-family:"Times New Roman","serif";
font-weight:bold;}
h3
{mso-style-priority:9;
mso-style-link:"Título 3 Car";
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:13.5pt;
font-family:"Times New Roman","serif";
font-weight:bold;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Texto de globo Car";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.EstiloCorreo17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.Ttulo1Car
{mso-style-name:"Título 1 Car";
mso-style-priority:9;
mso-style-link:"Título 1";
font-family:"Times New Roman","serif";
font-weight:bold;}
span.Ttulo2Car
{mso-style-name:"Título 2 Car";
mso-style-priority:9;
mso-style-link:"Título 2";
font-family:"Times New Roman","serif";
font-weight:bold;}
span.Ttulo3Car
{mso-style-name:"Título 3 Car";
mso-style-priority:9;
mso-style-link:"Título 3";
font-family:"Times New Roman","serif";
font-weight:bold;}
span.name
{mso-style-name:name;}
span.xref-sep
{mso-style-name:xref-sep;}
span.apple-converted-space
{mso-style-name:apple-converted-space;}
p.contributor-listreveal, li.contributor-listreveal, div.contributor-listreveal
{mso-style-name:contributor-list__reveal;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.contributor-listtoggler
{mso-style-name:contributor-list__toggler;}
span.collapsed-text
{mso-style-name:collapsed-text;}
span.z-PrincipiodelformularioCar
{mso-style-name:"z-Principio del formulario Car";
mso-style-priority:99;
mso-style-link:"z-Principio del formulario";
font-family:"Arial","sans-serif";
display:none;}
span.z-FinaldelformularioCar
{mso-style-name:"z-Final del formulario Car";
mso-style-priority:99;
mso-style-link:"z-Final del formulario";
font-family:"Arial","sans-serif";
display:none;}
span.title
{mso-style-name:title;}
span.caption-title
{mso-style-name:caption-title;}
p.first-child, li.first-child, div.first-child
{mso-style-name:first-child;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
span.ali-license-ref
{mso-style-name:ali-license-ref;}
span.TextodegloboCar
{mso-style-name:"Texto de globo Car";
mso-style-priority:99;
mso-style-link:"Texto de globo";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
/* List Definitions */
@list l0
{mso-list-id:12651182;
mso-list-template-ids:-1260503204;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1
{mso-list-id:167839617;
mso-list-template-ids:769680406;}
@list l2
{mso-list-id:453527764;
mso-list-template-ids:1019672398;}
@list l2:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3
{mso-list-id:1335837096;
mso-list-template-ids:593136086;}
@list l3:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l4
{mso-list-id:1898128351;
mso-list-template-ids:-599617768;}
@list l4:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l5
{mso-list-id:1976057510;
mso-list-template-ids:1719703442;}
@list l5:level1
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="2050" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal style='background:white'><cite><span style='font-family:
"Arial","sans-serif"'>Science </span></cite><span
class=apple-converted-space><span style='font-family:"Arial","sans-serif"'> </span></span><span
style='font-family:"Arial","sans-serif"'>05 Jan 2018:<br>
Vol. 359, Issue 6371, eaam7240<br>
DOI: 10.1126/science.aam7240<o:p></o:p></span></p>
<h1 style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;background:white'><span style='font-size:8.0pt;font-family:
"Helvetica","sans-serif";color:#333333;font-weight:normal'><o:p> </o:p></span></h1>
<h1 style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;background:white'><span style='font-family:"Helvetica","sans-serif";
color:#333333;font-weight:normal'>Declining oxygen in the global ocean and
coastal waters<o:p></o:p></span></h1>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-left:0in;text-indent:
-.25in;line-height:18.0pt;mso-list:l2 level1 lfo4;background:white'><![if !supportLists]><span
style='font-size:10.0pt;font-family:Symbol'><span style='mso-list:Ignore'>·<span
style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span class=name><span style='font-family:"Helvetica","sans-serif"'>Denise
Breitburg</span></span><span style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-1"
id=xref-award-group-2-1><sup><span style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>1</span></sup></a></span><span
class=xref-sep><span style='font-size:8.0pt;font-family:"Helvetica","sans-serif"'>,</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#corresp-1"
id=xref-corresp-1-1><span style='font-size:8.0pt;color:windowtext;border:none windowtext 1.0pt;
padding:0in'>*</span></a>,<span class=apple-converted-space> </span><span
class=name>Lisa A. Levin</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-2"
id=xref-award-group-4-1><sup><span style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>2</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Andreas Oschlies</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-3"
id=xref-award-group-1-1><sup><span style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>3</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Marilaure Grégoire</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-4"
id=xref-award-group-5-1><sup><span style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>4</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Francisco P. Chavez</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-5"
id=xref-aff-5-1><sup><span style='font-size:8.0pt;color:windowtext;border:none windowtext 1.0pt;
padding:0in'>5</span></sup></a>,<span class=apple-converted-space> </span><span
class=name>Daniel J. Conle</span></span><span class=name><span lang=FR
style='font-family:"Helvetica","sans-serif"'>y</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-6"
id=xref-aff-6-1><sup><span lang=FR style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>6</span></sup></a></span><span
lang=FR style='font-family:"Helvetica","sans-serif"'>,<span
class=apple-converted-space> </span><span class=name>Véronique Garçon</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-7"
id=xref-aff-7-1><sup><span lang=FR style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>7</span></sup></a></span><span
lang=FR style='font-family:"Helvetica","sans-serif"'>,<span
class=apple-converted-space> </span><span class=name>Denis Gilbert</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-8"
id=xref-aff-8-1><sup><span lang=FR style='font-size:8.0pt;color:windowtext;
border:none windowtext 1.0pt;padding:0in'>8</span></sup></a></span><span
lang=FR style='font-family:"Helvetica","sans-serif"'>,<span
class=apple-converted-space> </span><span class=name>Dimitri Gutiérrez</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-9"
id=xref-aff-9-1><sup><span style='font-size:8.0pt;color:windowtext;border:none windowtext 1.0pt;
padding:0in'>9</span></sup></a></span><span class=xref-sep><span
style='font-size:8.0pt;font-family:"Helvetica","sans-serif"'>,</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-10"
id=xref-aff-10-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>10</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Kirsten Isensee</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-11"
id=xref-aff-11-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>11</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Gil S. Jacinto</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-12"
id=xref-aff-12-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>12</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Karin E. Limburg</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-13"
id=xref-aff-13-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>13</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Ivonne Montes</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-14"
id=xref-aff-14-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>14</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>S. W. A. Naqvi</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-15"
id=xref-aff-15-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>15</span></sup></a></span><span
class=xref-sep><span style='font-size:8.0pt;font-family:"Helvetica","sans-serif"'>,</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#fn-1"
id=xref-fn-1-1><span style='font-size:8.0pt;color:windowtext;border:none windowtext 1.0pt;
padding:0in'>†</span></a>,<span class=apple-converted-space> </span><span
class=name>Grant C. Pitcher</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-16"
id=xref-aff-16-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>16</span></sup></a></span><span
class=xref-sep><span style='font-size:8.0pt;font-family:"Helvetica","sans-serif"'>,</span></span><span
style='font-family:"Helvetica","sans-serif"'><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-17"
id=xref-aff-17-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>17</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Nancy N. Rabalais</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-18"
id=xref-aff-18-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>18</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Michael R. Roman</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-19"
id=xref-aff-19-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>19</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Kenneth A. Rose</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-19"
id=xref-aff-19-2><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>19</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Brad A. Seibel</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-20"
id=xref-aff-20-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>20</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Maciej Telszewski</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-21"
id=xref-aff-21-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>21</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Moriaki Yasuhara</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-22"
id=xref-aff-22-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>22</span></sup></a>,<span
class=apple-converted-space> </span><span class=name>Jing Zhang</span><a
href="http://science.sciencemag.org/content/359/6371/eaam7240?utm_campaign=toc_sci-mag_2018-01-04&et_rid=34815706&et_cid=1771554#aff-23"
id=xref-aff-23-1><sup><span style='font-size:8.0pt;color:windowtext;border:
none windowtext 1.0pt;padding:0in'>23</span></sup></a></span><span
style='font-family:"Roboto","serif"'><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-left:0in;text-indent:
-.25in;line-height:18.0pt;mso-list:l0 level1 lfo5;background:white;box-sizing: inherit'><![if !supportLists]><span
style='font-size:10.0pt;font-family:Symbol;color:#333333'><span
style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-family:"Roboto","serif";
color:#333333'><o:p> </o:p></span></p>
<h2 style='margin:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1.5rem'><span style='font-family:"Helvetica","sans-serif";color:#333333'>Beneath
the waves, oxygen disappears<o:p></o:p></span></h2>
<p style='mso-margin-top-alt:2.8pt;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;line-height:18.0pt;background:#E6E6E6;box-sizing: inherit;
transition: background-color 1s ease-in-out 1s' id=p-3><span style='font-family:
"Arial","sans-serif";color:#333333'>As plastic waste pollutes the oceans and
fish stocks decline, unseen below the surface another problem grows:
deoxygenation. Breitburg<span class=apple-converted-space> </span><em><span
style='font-family:"Arial","sans-serif"'>et al.</span></em><span
class=apple-converted-space> </span>review the evidence for the downward
trajectory of oxygen levels in increasing areas of the open ocean and coastal
waters. Rising nutrient loads coupled with climate change—each resulting from
human activities—are changing ocean biogeochemistry and increasing oxygen
consumption. This results in destabilization of sediments and fundamental
shifts in the availability of key nutrients. In the short term, some
compensatory effects may result in improvements in local fisheries, such as in
cases where stocks are squeezed between the surface and elevated oxygen minimum
zones. In the longer term, these conditions are unsustainable and may result in
ecosystem collapses, which ultimately will cause societal and economic harm.<o:p></o:p></span></p>
<p style='mso-margin-top-alt:11.25pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;line-height:18.0pt;background:#E6E6E6;
box-sizing: inherit;transition: background-color 1s ease-in-out 1s' id=p-4><em><span
style='font-family:"Arial","sans-serif";color:#333333'>Science</span></em><span
style='font-family:"Arial","sans-serif";color:#333333'>, this issue p.<span
class=apple-converted-space> </span><a
href="http://science.sciencemag.org/lookup/doi/10.1126/science.aam7240"><b><span
style='color:#37588A'>eaam7240</span></b></a><o:p></o:p></span></p>
<p style='mso-margin-top-alt:11.25pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;line-height:18.0pt;background:#E6E6E6'><span
style='font-family:"Arial","sans-serif";color:#333333'><o:p> </o:p></span></p>
<h2 style='margin:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1.5rem'><span style='font-family:"Arial","sans-serif";color:#333333'>Structured
Abstract<o:p></o:p></span></h2>
<h3 style='mso-margin-top-alt:12.0pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1rem'><span style='font-family:"Arial","sans-serif";color:#333333'>BACKGROUND<o:p></o:p></span></h3>
<p style='margin:0in;margin-bottom:.0001pt;line-height:18.0pt;background:#E6E6E6;
box-sizing: inherit;transition: background-color 1s ease-in-out 1s' id=p-5><span
style='font-family:"Arial","sans-serif";color:#333333'>Oxygen concentrations in
both the open ocean and coastal waters have been declining since at least the
middle of the 20th century. This oxygen loss, or deoxygenation, is one of the
most important changes occurring in an ocean increasingly modified by human
activities that have raised temperatures, CO</span><sub><span style='font-size:
9.0pt;font-family:"Arial","sans-serif";color:#333333'>2</span></sub><span
style='font-family:"Arial","sans-serif";color:#333333'>levels, and nutrient
inputs and have altered the abundances and distributions of marine species.
Oxygen is fundamental to biological and biogeochemical processes in the ocean.
Its decline can cause major changes in ocean productivity, biodiversity, and
biogeochemical cycles. Analyses of direct measurements at sites around the
world indicate that oxygen-minimum zones in the open ocean have expanded by
several million square kilometers and that hundreds of coastal sites now have
oxygen concentrations low enough to limit the distribution and abundance of
animal populations and alter the cycling of important nutrients.<o:p></o:p></span></p>
<h3 style='mso-margin-top-alt:12.0pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1rem'><span style='font-family:"Arial","sans-serif";color:#333333'>ADVANCES<o:p></o:p></span></h3>
<p style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;line-height:18.0pt;background:#E6E6E6;box-sizing: inherit;
transition: background-color 1s ease-in-out 1s' id=p-6><span style='font-family:
"Arial","sans-serif";color:#333333'>In the open ocean, global warming, which is
primarily caused by increased greenhouse gas emissions, is considered the
primary cause of ongoing deoxygenation. Numerical models project further oxygen
declines during the 21st century, even with ambitious emission reductions.
Rising global temperatures decrease oxygen solubility in water, increase the
rate of oxygen consumption via respiration, and are predicted to reduce the
introduction of oxygen from the atmosphere and surface waters into the ocean
interior by increasing stratification and weakening ocean overturning
circulation.<o:p></o:p></span></p>
<p style='mso-margin-top-alt:11.25pt;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;line-height:18.0pt;background:#E6E6E6;box-sizing: inherit;
transition: background-color 1s ease-in-out 1s' id=p-7><span style='font-family:
"Arial","sans-serif";color:#333333'>In estuaries and other coastal systems
strongly influenced by their watershed, oxygen declines have been caused by
increased loadings of nutrients (nitrogen and phosphorus) and organic matter,
primarily from agriculture; sewage; and the combustion of fossil fuels. In many
regions, further increases in nitrogen discharges to coastal waters are
projected as human populations and agricultural production rise. Climate change
exacerbates oxygen decline in coastal systems through similar mechanisms as
those in the open ocean, as well as by increasing nutrient delivery from
watersheds that will experience increased precipitation.<o:p></o:p></span></p>
<p style='mso-margin-top-alt:11.25pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;line-height:18.0pt;background:#E6E6E6;
box-sizing: inherit;transition: background-color 1s ease-in-out 1s' id=p-8><span
style='font-family:"Arial","sans-serif";color:#333333'>Expansion of low-oxygen
zones can increase production of N</span><sub><span style='font-size:9.0pt;
font-family:"Arial","sans-serif";color:#333333'>2</span></sub><span
style='font-family:"Arial","sans-serif";color:#333333'>O, a potent greenhouse
gas; reduce eukaryote biodiversity; alter the structure of food webs; and
negatively affect food security and livelihoods. Both acidification and
increasing temperature are mechanistically linked with the process of
deoxygenation and combine with low-oxygen conditions to affect biogeochemical,
physiological, and ecological processes. However, an important paradox to
consider in predicting large-scale effects of future deoxygenation is that high
levels of productivity in nutrient-enriched coastal systems and upwelling areas
associated with oxygen-minimum zones also support some of the world’s most
prolific fisheries.<o:p></o:p></span></p>
<h3 style='mso-margin-top-alt:12.0pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1rem'><span style='font-family:"Arial","sans-serif";color:#333333'>OUTLOOK<o:p></o:p></span></h3>
<p style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:11.25pt;
margin-left:0in;line-height:18.0pt;background:#E6E6E6;box-sizing: inherit;
transition: background-color 1s ease-in-out 1s' id=p-9><span style='font-family:
"Arial","sans-serif";color:#333333'>Major advances have been made toward
understanding patterns, drivers, and consequences of ocean deoxygenation, but
there is a need to improve predictions at large spatial and temporal scales
important to ecosystem services provided by the ocean. Improved numerical
models of oceanographic processes that control oxygen depletion and the
large-scale influence of altered biogeochemical cycles are needed to better
predict the magnitude and spatial patterns of deoxygenation in the open ocean,
as well as feedbacks to climate. Developing and verifying the next generation
of these models will require increased in situ observations and improved
mechanistic understanding on a variety of scales. Models useful for managing
nutrient loads can simulate oxygen loss in coastal waters with some skill, but
their ability to project future oxygen loss is often hampered by insufficient
data and climate model projections on drivers at appropriate temporal and
spatial scales. Predicting deoxygenation-induced changes in ecosystem services
and human welfare requires scaling effects that are measured on individual
organisms to populations, food webs, and fisheries stocks; considering combined
effects of deoxygenation and other ocean stressors; and placing an increased
research emphasis on developing nations. Reducing the impacts of other
stressors may provide some protection to species negatively affected by
low-oxygen conditions. Ultimately, though, limiting deoxygenation and its
negative effects will necessitate a substantial global decrease in greenhouse
gas emissions, as well as reductions in nutrient discharges to coastal waters.<o:p></o:p></span></p>
<p class=MsoNormal align=center style='text-align:center;line-height:18.0pt;
background:#E6E6E6'><a
href="https://d2ufo47lrtsv5s.cloudfront.net/content/sci/359/6371/eaam7240/F1.large.jpg?width=800&height=600&carousel=1"
title="Low and declining oxygen levels in the open ocean and coastal waters affect processes ranging from biogeochemistry to food security. The global map indicates coastal sites where anthropogenic nutrients have exacerbated or caused O2 declines to "><b><span
style='font-family:"Arial","sans-serif";color:#37588A;text-decoration:none'><img
border=0 width=440 height=199 id="Imagen_x0020_1"
src="cid:image001.gif@01D38654.763FBDA0"
alt="https://d2ufo47lrtsv5s.cloudfront.net/content/sci/359/6371/eaam7240/F1.medium.gif"></span></b></a><span
style='font-family:"Arial","sans-serif";color:#333333'><o:p></o:p></span></p>
<p class=MsoNormal align=center style='mso-margin-top-alt:auto;margin-bottom:
5.65pt;margin-left:0in;text-align:center;text-indent:-.25in;mso-list:l5 level1 lfo6;
background:#E6E6E6'><![if !supportLists]><span style='font-size:10.0pt;
font-family:Symbol;color:gray'><span style='mso-list:Ignore'>·<span
style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span style='font-family:"Arial","sans-serif";
color:gray'><a
href="https://d2ufo47lrtsv5s.cloudfront.net/content/sci/359/6371/eaam7240/F1.large.jpg?download=true"
title="Download Figure1"><span class=apple-converted-space><b><span
style='color:#37588A;text-decoration:none'> </span></b></span><span
class=title><b><span style='color:#37588A;text-decoration:none'>Download
high-res image</span></b></span></a> <a
href="https://d2ufo47lrtsv5s.cloudfront.net/content/sci/359/6371/eaam7240/F1.large.jpg"
target="_blank"><span class=apple-converted-space><b><span style='color:#37588A;
text-decoration:none'> </span></b></span><span class=title><b><span
style='color:#37588A;text-decoration:none'>Open in new tab</span></b></span></a>
<a href="http://science.sciencemag.org/highwire/powerpoint/704191"><span
class=apple-converted-space><b><span style='color:#37588A;text-decoration:none'> </span></b></span><span
class=title><b><span style='color:#37588A;text-decoration:none'>Download Powerpoint</span></b></span></a><o:p></o:p></span></p>
<p class=MsoNormal align=center style='text-align:center;line-height:18.0pt;
background:#E6E6E6'><span class=caption-title><b><span style='font-family:"Arial","sans-serif";
color:#333333'>Low and declining oxygen levels in the open ocean and coastal
waters affect processes ranging from biogeochemistry to food security.</span></b></span><span
style='font-family:"Arial","sans-serif";color:#333333'><o:p></o:p></span></p>
<p class=first-child style='mso-margin-top-alt:11.25pt;margin-right:0in;
margin-bottom:11.25pt;margin-left:0in;line-height:18.0pt;background:#E6E6E6'><span
style='font-family:"Arial","sans-serif";color:#333333'>The global map indicates
coastal sites where anthropogenic nutrients have exacerbated or caused O</span><sub><span
style='font-size:7.0pt;font-family:"Arial","sans-serif";color:#333333'>2</span></sub><span
class=apple-converted-space><span style='font-family:"Arial","sans-serif";
color:#333333'> </span></span><span style='font-family:"Arial","sans-serif";
color:#333333'>declines to <2 mg liter</span><sup><span style='font-size:
7.0pt;font-family:"Arial","sans-serif";color:#333333'>−1</span></sup><span
class=apple-converted-space><span style='font-family:"Arial","sans-serif";
color:#333333'> </span></span><span style='font-family:"Arial","sans-serif";
color:#333333'>(<63 μmol liter</span><sup><span style='font-size:7.0pt;
font-family:"Arial","sans-serif";color:#333333'>−1</span></sup><span
style='font-family:"Arial","sans-serif";color:#333333'>) (red dots), as well as
ocean oxygen-minimum zones at 300 m of depth (blue shaded regions). [Map
created from data provided by R. Diaz, updated by members of the GO</span><sub><span
style='font-size:7.0pt;font-family:"Arial","sans-serif";color:#333333'>2</span></sub><span
style='font-family:"Arial","sans-serif";color:#333333'>NE network, and
downloaded from the World Ocean Atlas 2009].<o:p></o:p></span></p>
<h2 style='margin:0in;margin-bottom:.0001pt;background:#E6E6E6;box-sizing: inherit;
font-size:1.5rem'><span style='font-family:"Arial","sans-serif";color:#333333'>Abstract<o:p></o:p></span></h2>
<p style='mso-margin-top-alt:2.8pt;margin-right:0in;margin-bottom:0in;
margin-left:0in;margin-bottom:.0001pt;line-height:18.0pt;background:#E6E6E6;
box-sizing: inherit;transition: background-color 1s ease-in-out 1s' id=p-11><span
style='font-family:"Arial","sans-serif";color:#333333'>Oxygen is fundamental to
life. Not only is it essential for the survival of individual animals, but it
regulates global cycles of major nutrients and carbon. The oxygen content of
the open ocean and coastal waters has been declining for at least the past half-century,
largely because of human activities that have increased global temperatures and
nutrients discharged to coastal waters. These changes have accelerated
consumption of oxygen by microbial respiration, reduced solubility of oxygen in
water, and reduced the rate of oxygen resupply from the atmosphere to the ocean
interior, with a wide range of biological and ecological consequences. Further
research is needed to understand and predict long-term, global- and
regional-scale oxygen changes and their effects on marine and estuarine
fisheries and ecosystems.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
</div>
<div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2">
<br /><br />
<hr style='border:none; color:#909090; background-color:#B0B0B0; height: 1px; width: 99%;' />
<table style='border-collapse:collapse;border:none;'>
<tr>
<td style='border:none;padding:0px 15px 0px 8px'>
<a href="https://www.avast.com/antivirus">
<img border=0 src="http://static.avast.com/emails/avast-mail-stamp.png" alt="Avast logo" />
</a>
</td>
<td>
<p style='color:#3d4d5a; font-family:"Calibri","Verdana","Arial","Helvetica"; font-size:12pt;'>
This email has been checked for viruses by Avast antivirus software.
<br><a href="https://www.avast.com/antivirus">www.avast.com</a>
</p>
</td>
</tr>
</table>
<br />
<a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"> </a></div></body>
</html>