Low-oxygen problems in Hood Canal and along the Washington-Oregon Coast are highlighted as “case studies” in a new federal report regarding the growing number of “dead zones” across the United States. See “Scientific Assessment of Hypoxia in U.S. Coastal Waters” (PDF 2.7 mb).
Incidents of hypoxia have increased 30-fold since 1960, according to the report. The new federal review describes the causes of hypoxia, discusses past and ongoing research efforts and lays out policy recommendations to deal with the problem. Eight troubled waterways are reviewed as “case studies.”
In a news release (PDF 116 kb) accompanying the report, Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration, offered these comments regarding hypoxia and the seasonal low-oxygen area off the coast of Washington and Oregon:
“The report shows good progress on research into the causes of hypoxia and the specific management requirements to restore systems such as the Gulf of Mexico and Chesapeake Bay, but we still have a long way to go to reduce this environmental threat. The discovery of a new seasonal hypoxic zone off the coast of Oregon and Washington that may be linked to a changing climate emphasizes the complexity of this issue.”
That West Coast dead zone is now ranked the second largest in the United States and the third largest in the world. Federal officials say there may be serious consequences to the ecological health of the region.
Lisa Jackson, administrator of the Environmental Protection Agency, said the EPA is proud to have played a role in the research leading up to the report:
“These growing dead zones endanger fragile ecosystems and potentially jeopardize billions of dollars in economic activity. This science can be the foundation for measures that will preserve our waters and reverse the trend, including innovative, watershed-based solutions to this challenge.”
Mike Lee, a reporter with the San Diego Union-Bulletin, interviewed Tony Koslow, who studies low-oxygen areas at the Scripps Institution of Oceanography.
“This is a large phenomenon not due to nutrient outflows” from land, Lee quoted Koslow as saying. “The big question is, ‘Is this due to climate change?’ ”
As the oxygen-rich surface layers warm up, they mix less with colder layers down deep where oxygen levels are low, Koslow said. Global climate models predict that the oxygen levels in deep oceans will decline 20 to 40 percent the next century.
“There are substantial ecosystem concerns,” Koslow said. “A number of species that live in the deep ocean are very sensitive to changes in oxygen levels. These species — although they are not of commercial interest — are prey to squid, fish, marine mammals and seabirds, so changes in oxygen will have repercussions throughout the food web.”
The report suggests these policy actions:
- Develop and implement cost-effective and scientifically
sound nutrient reduction strategies to achieve healthy water
quality in rivers, lakes and coastal waters. - Improve ecosystem models to assess how hypoxia
affects commercially important fish populations in order to
refine management strategies to protect coastal economies. - Improve scientific understanding for emerging sites such
as the Oregon and Washington shelf, where hypoxia may be
driven primarily by events linked to climate change. This
knowledge will help managers mitigate impacts on natural
resources and coastal economies. - Expand stream and river monitoring to document extent
and sources of nutrients and progress in achieving management
goals. This can lead to more strategic and effective targeting of
nutrient reduction actions. - More systematically monitor oxygen levels in coastal
waters using new technologies and observing systems. This is
critical for forecast model development, fisheries management,
and determining nutrient reduction success.
