Oxygen Depletion/title> <meta name="author"content="Garry Fletcher"> <meta name="description" content="Oxygen depletion,Ecological Sustainability,Ecosystem"> <meta name="keywords" content="oxygen in water,Vancouver Island Ecosystems,ocean research,ocean sustainability,ecosystem integrity,ecosystem sustainability"> </head> <body bgcolor="#ffffff"> <div align="center"> <p><b><i><font size="4" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">4.3 Oxygen Depletion</font></i></b></p> </div> <p><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">FROM WATER:</font></p> <p><a href="http://www.unep.org/geo/geo4/report/04_Water.pdf"><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">http://www.unep.org/geo/geo4/report/04_Water.pdf</font></a></p> <p><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">OXYGEN DEPLETION: </font></p> <p><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">A harmful algal bloom of the dinoflagellates Noctiluca scintillans, known as a red tide </font></p> <p><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">Organic materials, from such sources as algal blooms and discharges from domestic wastewater treatment plants and food-processing operations, are decomposed by oxygen-consuming microbes in waterbodies. This pollution is typically measured as the biochemical oxygen demand (BOD). High BOD levels can cause oxygen depletion, jeopardizing fish and other aquatic species. Lake Erie’s oxygen- depleted bottom zone, for example, has expanded since 1998, with negative environmental impacts. Some coastal areas also undergo oxygen depletion, including the eastern and southern coasts of North America, southern coasts of China and Japan, and large areas around Europe (WWAP 2006). Oxygen depletion in the Gulf of Mexico has created a huge “dead zone,” with major negative impacts on biodiversity and fisheries (MA 2005) (see Chapter 6). </font></p> <p><font face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular"> </font></p> <p><a href="pollutants.htm"><font face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">4.4 Ocean Pollutants</font></a></p> <p><font size="2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular"><a href="index.htm"> Index</a></font></p> <table width="873" border="1" cellspacing="2" cellpadding="2"> <tr> <td bgcolor="#ccffff" width="50%"> <p><font size="-2"><a href="http://www.oceandiscovery.ca" target="_blank"><img src="logo.jpg" alt="Shaw Ocean Discovery Centre" width="92" height="71" align="left" border="2"></a><i><b><font face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular">This file was created in 2008 as a marine education resource supported by the <a title="Shaw Ocean Discovery Centre" href="http://www.oceandiscovery.ca" target="_blank">Shaw Ocean Discovery Centre in Sidney</a></font></b></i></font></p> </td> <td> <div align="center"> <a title="Coastal Ecosystems Metchosin" href="../marineecosystems.htm" target="_blank"><img src="../cover/coastalicons.jpg" alt="Coastal Ecosystems, Metchosin" width="181" height="68" border="2"></a></div> </td> <td bgcolor="#ccffff" width="50%"> <div align="left"> <font size="-2"><a title="racerocks.com homepage" onmouseover="MM_swapImage('rrcomcolors','','logo/rrcomcolors2_f2.jpg',1)" onmouseout="MM_swapImgRestore();" href="http://www.racerocks.com"><img src="../links/rrcomcolors.jpg" alt="racerocks.com" name="rrcomcolors" height="68" width="115" align="right" border="2"></a></font><font size="-2" face="Arial,Helvetica,Geneva,Swiss,SunSans-Regular"><b>Website courtesy of racerocks.com & <a href="http://www.pearsoncollege.ca">Lester B. Pearson College.</a> <i>Copyright: 2008 </i></b><a href="http://www.racerocks.com/racerock/contacts/gf/garry.htm" target="_blank"><b>Garry Fletcher</b></a><b><i> Marine Education Consulting,<br> </i></b></font></div> </td> </tr> </table> <p></p> </body> </html>