2009 Hypoxia updates

The PISCO hypoxia team at Oregon State University started monitoring the coastal ocean off Oregon in early April this year.  The spring transition occurred in late April or early May.  Spring transition signals a change in coastal wind patterns.  Each year, the coastal winds switch from the southerly winds of winter to the northerly winds of summer.

The summer winds are favorable to upwelling -- a process that transports the nutrients to the ocean surface, feeding the near-shore food chain.  This shift in the winds and resulting upwelling create the conditions for hypoxia along the coast.  PISCO is monitoring the waters off the coast extensively this summer, with an average of 9 research trips planned for each month until early October.  So far, the oxygen values at southern sites (off Strawberry Hill) range between 1 and 1.5 ml / l-1 across much of the shelf.  Off Lincoln Beach, oxygen values are higher, in the range of 1.2 to 2.5 ml l-1. 

These numbers indicate that low oxygen levels are starting to build over the waters south of Newport. While these numbers are not as low as what  have been observed in past years when hypoxic events are most severe, the combination of strong upwelling and strong phytoplankton blooms that we have experienced to date suggests that close attention to changing ocean conditions and oxygen values are warranted for the coming season.  PISCO will provide updates throughout the season. 

For more information, please check our new website:  www.piscoweb.org or contact Liz Riley at liz.riley@science.oregonstate.edu