Oceanic Dead Zones
By: Bryan Duggan
Water and Environmental Specialist
As coastal peoples, the Coquille Indian Tribe has long depended upon the
abundant resources of the Pacific Ocean to provide both subsistence and a vehicle for
cultural identity. This fact has not changed even though the Coquille Peoples have
adapted to a modern economy. But as we all know the world is a dynamic system,
constantly changing, and this is no less a truth than for the oceanic ecosystem.
Since 2002 a well documented and consistent phenomenon has been developing
off shore of the Oregon, Washington and parts of California coast lines. Called Dead
Zones, these areas are expanses of ocean that lose most of their marine life during the
summer due to a lack of oxygen, called hypoxia. Hypoxia traditionally forms when
excess nutrients, such as fertilizers and sewage flow down into our freshwater streams
and rivers and are flushed out into the ocean. Tiny microscopic ocean plants called
phytoplankton, bloom, die, and then decompose robbing the ocean of life sustaining
oxygen. The Pacific Northwest dead zones are located in one of the nation's most
important fisheries, and the impacts of these dead zones both economically and
ecologically are devastating.
Researchers at the Department of Oceanography at Oregon State University have
been in the fore front of studying these dead zones. Using robotic unmanned “gliders”
researchers have been able to collect continuous and real time data of oceanic conditions.
Similar to the data loggers that Tribal natural resources managers use to collect water
quality information on tribal lands; these instruments are programmed to patrol the seas
nonstop on its own for up to three weeks at a time—all the while measuring the water's
oxygen concentration, temperature, salinity, density, chlorophyll content, and other
variables that reflect its ecological health.
OSU researchers are working to understand the relationship of changing oceanic
conditions, driven by a changing climate, to the observed parameters such as oxygen and
nutrient contents of the near shore waters. Although many variables contribute to the
dead zones, one of the most clearly understood is the link of high nutrient runoff entering
the system from human behaviors.
Nonpoint source releases of nutrient pollutants from agricultural, urban, and
municipality actions have multiple paths to the waterways. The abundance and wide
distribution of these pollutants make it difficult and challenging to control; however; not
impossible. As we finally enter summer, and our economic and social activities increase
it is up to us to ensure that we add the extra value to responsible nutrient containment on
public and private activities.
How big will this year’s dead zone be? How long will it last, and to what extent
will it unfold? These are the questions that researchers at OSU hope to answer with new
technologies that are on hand. For us, it is important that we do our part in managing and
controlling our activities accordingly.