· Ocean has a DO concentration that range from 1 to 12 ppm.

· Fish died of suffocation, because the DO level was below the critical threshold of 4 ppm.

· 4 ppm is the minimum level of oxygen require for fish to breath.
· The condition is known as hypoxia, meaning “low oxygen in the water.”

· Hypoxia is a phenomenon that occurs in aquatic environments as dissolved oxygen.

· Hypoxia can occur throughout the water column and also at high altitudes.

· There are 375 hypoxic coast zones around the world, concentrated in coastal areas in Western Europe, the Eastern and Southern coast of the U.S.A and East Asia, particularly in Japan.

· To combat hypoxia we have to reduce the amount of phosphorus & nitrogen (nutrients) in water.

Gulf of Mexico hypoxia

Many scientist talks about Gulf of Mexico hypoxia. They said hypoxia come from of East of the Mississippi river and the area between the 10 and 200m isobaths from Brownsville, TX. Scientist been measure water temperature, salinity, dissolved oxygen and fluorescence. During the 2009 summer ground fish cruise come to the Gulf of Mexico.From June 8th through July 18th the scientist starts they research. They begin in the area of Pascagoula, MS and then the area from Brownsville to Galveston, TX. They view of dissolved oxygen from Gulf of Mexico Southeast area to Northwest and North-Central

Hypoxia in Oregon Coast

In the summer of 2002, oxygen levels in the water near the Oregon coast plunged so low that fishes, crabs, and other marine organisms had to flee or die in the suffocating water. Had never seen in Oregon, but have recurred every summer. Scientist is working in the water of Oregon coast. Oregon coast turn deadly, causing one of the largest known hypoxic dead zones in the world. Scientist is also looking closely at how Oregon’s marine life is responding to the dead zone. In the summer of 2006 when oxygen levels dropped to historic lows and hypoxic water could be found in large areas along the Washington and Oregon coast. Many species of bottom dwelling marine organisms when oxygen declines to hypoxic and anoxic levels. When dead zones are short-lived or moderate in severity, the risk of marine life mortality event has been low. This small decrease in overall oxygen levels has probably primed the pump for hypoxia in the Pacific Northwest. These observations can enable scientists to better forecast where and when future low oxygen zones are likely to occur.

Hypoxia II