DEADLY HYPOXIC
EVENT FINALLY CONCLUDES
The longest, largest
and most
devastating hypoxic event ever observed in marine waters off the During mid-October,
a normal
shift arrived from summer southward-blowing winds to fall and winter
northward-blowing winds, resulting in the end of the upwelling season
and a
rise in dissolved oxygen to levels that can generally support marine
life,
scientists said. The oxygen levels should continue to increase
throughout the
next month. Monitoring efforts
will continue,
new technology will be utilized, federal funding will be sought for
more work
in the area, and work is already under way to identify the amounts of
biological damage done by this event, the fifth "dead zone" in five
years and, literally, one for the record books. In 2006, the
low-oxygen waters
off "The figures were
just off
the charts this year," said Francis Chan, a marine ecologist with OSU
and
the Partnership for Interdisciplinary Studies of Coastal Oceans, or
PISCO. Any
level of dissolved oxygen below 1.4 milliliters per liter is considered
hypoxic
for most marine life, and many areas were below that, some 10-30 times
lower
than normal, others approaching zero. "We had stronger and
more
persistent winds from the north, causing greater upwelling and more
severe
hypoxic conditions, than we had ever seen before," said Jack Barth, OSU
professor of oceanic and atmospheric sciences. "The winds were outside
the
normal summer range of anything seen in decades." Even though hypoxic
concerns
erupted for the fifth year in a row, the events are still considered an
anomaly, Barth said. "Given what's
happened, it
would not be surprising if hypoxic conditions developed next year as
well, but
we can't say that for sure," Barth said. "And we don't know what is
causing the change in wind patterns that ultimately results in marine
hypoxia.
There's a pressing need to better understand these ocean systems, and
all this
points to an ongoing need for a better coast-wide observing system." This year's hypoxic
event began
in mid-June, and in the Heceta Bank off The event, due to
its severity
and unusual nature, attracted national media attention. The next order of
business, scientists
say, is to continue monitoring the recovery from the dead zone. OSU
will work
closely with the Oregon Department of Fish and Wildlife, and consult
with local
fishermen to verify their findings. The event is complex –
low oxygen waters
are not static, they move up and down the coast and also towards shore,
resulting in patchiness and variable effects in some areas. This winter, the
ocean off
Newport will be continuously monitored for the first time by a
submersible
"glider" that will provide information on ocean conditions, and a
sophisticated new buoy will be moored off Newport along the central
Oregon
coast to measure biological productivity, dissolved oxygen,
temperature,
salinity, current velocity and other data. "We're very
interested now
in seeing how the ocean recovers," Chan said. "There is much we don't
know about how sensitive or resilient these ocean systems are, but an
event of
this magnitude gives us the chance to gain some real insights into how
marine
systems function and can recover. We expect some fish to return fairly
quickly,
but with other life forms, it's hard to say. And we have deadlines, we
need to
get a lot of this information before another possible hypoxic event
starts next
year." Funding is still
inadequate for
the types of video monitoring, water sampling, comprehensive ocean
observations
and research that is needed, the OSU scientists said. Changes in oceanic
and
atmospheric conditions are expected as a result of global climate
change, and
events such as this summer's stronger and more persistent winds from
the north,
contributing to hypoxia, are consistent with such predictions, the OSU
researchers said. However, at this point there is no data or basis to
suggest
such cause and effect mechanisms, they said. There are also no known
links to
other marine or atmospheric events such as El Nino or the Pacific
Decadal
Oscillation. When the system
operates
normally, upwelling off This type of "dead
zone" is different than those that have occurred elsewhere in the ##
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