Of course it is the new normal. So long as we use our present
chemical dousing protocol, we will over load the ground water and
cause excessive nutrification of the lakes and parts of the ocean.
As
we have posted many times the actual solution to all this is the
establishment of biochar protocols. This naturally retains nutrients
in the soil until a root arrives and frees it. Better, any nutrients
re-released is reabsorbed. It is pretty neat and slowly been
understood and implemented.
Once
that becomes the standard, all these blooms will disappear' so
although these poisoning events are upsetting, they too shall pass
into history to be replaced by far better waterways.
Extreme algal
blooms: The new normal?
by Staff Writers
Washington DC (SPX) Apr 11, 2013
This NASA Landsat-5 image shows the record-breaking algal bloom in Lake Eerie in October of 2011. The green scum is mostly microcystis, a toxin to mammals. Credit: NASA.
A research team, led
by Carnegie's Anna Michalak, has determined that the 2011
record-breaking algal bloom in Lake Erie was triggered by long-term
agricultural practices coupled with extreme precipitation, followed
by weak lake circulation and warm temperatures. The team also
predicts that, unless agricultural policies change, the lake will
continue to experience extreme blooms. The research is published in
the online early edition of the Proceedings of the National Academy
of Sciences the week of April 1, 2013.
"The perfect
storm of weather events and agricultural practices that occurred in
2011 is unfortunately consistent with ongoing trends, which means
that more huge algal blooms can be expected in the future unless a
scientifically guided management plan is implemented for the region,"
remarked Michalak.
Fresh water algal
blooms can result when excessive amounts of phosphorus and nitrogen
are added to the water, typically as runoff from fertilized
agriculture. These excess nutrients encourage unusual growth of algae
and aquatic plants.
When the plants and
algae die, the decomposers that feed on them use up oxygen, which can
drop to levels too low for aquatic life to thrive. In the beginning,
the Lake Erie algae were almost entirely Microcytsis, an organism
that produces a liver toxin and can cause skin irritation.
The scientists
combined sampling and satellite-based observations of the lake with
computer simulations. The bloom began in the western region in
mid-July and covered an area of 230 square miles (600 km2). At its
peak in October, the bloom had expanded to over 1930 square miles
(5000 km2). Its peak intensity was over 3 times greater than any
other bloom on record.
The researchers looked
at numerous factors that could have contributed to the bloom
including land use, agricultural practices, runoff, wind,
temperature, precipitation, and circulation.
The use of three
agricultural nutrient management practices in the area can lead to
increased nutrient runoff: autumn fertilization, broadcast
fertilization, and reduced tillage. These practices have increased in
the region over the last decade.
Conditions in the fall
of 2010 were ideal for harvesting and preparing the fields,
increasing fertilizer application for the spring planting. A series
of strong storms the following spring caused large amounts of
phosphorus to run off into the lake.
In May alone rainfall
was over 6.5 inches (170 mm), a level more than 75% above the prior
20-year average for the month. This onslaught resulted in among the
largest observed spring phosphorus loads since 1975, when intensive
monitoring began.
Lake Erie was not
unusually calm and warm before the bloom. But after the bloom began,
warmer water and weaker currents encouraged a more productive bloom
than in prior years. The longer period of weak circulation and warmer
temperatures helped incubate the bloom and allowed the Microcytsis to
remain near the top of the water column. That had the added effect of
preventing the nutrients from being flushed out of the system.
The researchers' data
did not support the idea that land-use and crop choices contributed
to the increase in nutrient run-off that fueled the bloom.
To determine the
likelihood of future mega-blooms, the scientists analyzed climate
model simulations under both past and future climate conditions. They
found that severe storms become more likely in the future, with a 50%
increase in the frequency of precipitation events of.80 inch (20 mm)
or more of rain. Stronger storms, with greater than 1.2 inch (30 mm)
of rain, could be twice as frequent.
The authors believe
that future calm conditions with weak lake circulation after bloom
onset is also likely to continue since current trends show decreasing
wind speeds across the U.S. This would result in longer lasting
blooms and decreased mixing in the water column.
"Although future
strong storms may be part of the new normal," remarked Michalak.
"Better management practices could be implemented to provide
some relief to the problem."
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