SF Gate piece today...
CO{-2} study: Plankton fertilization may backfire
David Perlman, Chronicle Science Editor
Tuesday, March 16, 2010
San Francisco State's William P. Cochlan (second from rig...
For more than a dozen years, researchers have been fertilizing small
patches of the world's oceans with iron to see if they could make the
floating plants called phytoplankton flourish into massive blooms that
would absorb carbon dioxide, the worst planet-warming greenhouse gas
in the atmosphere.
The idea was that the absorbed carbon would sink to the ocean bottom
and remain there essentially forever. Many experts have hailed the
idea as one surefire solution to the problem of global warming.
Now a vexing new issue has risen to challenge the whole concept: A
major species of plankton that produces an environmental poison known
to threaten fish life as well as humans would pose a greater
environmental threat when fertilized with iron, according to a team of
American and Canadian scientists.
Their findings, published Monday in the online edition of the
Proceedings of the National Academy of Sciences, suggest that any
massive effort to fertilize the oceans should be done with extreme
caution, the researchers say.
"It is an indication that we are not masters of nature when it comes
to large-scale ecological manipulations," said Charles G. Trick, a
microbial biologist at the University of Western Ontario Medical
School, who led the research. "Any positive carbon sequestration must
be balanced against the evident and unforeseen environmental
consequences."
The first experiment
The international effort at fertilizing ocean plankton with iron to
absorb carbon dioxide from the atmosphere began nearly 20 years ago
with seagoing experiments led by Kenneth Coale, director of the Moss
Landing Marine Laboratories, and Kenneth Johnson of the Monterey Bay
Aquarium Research Institute.
The marine biologists and an international team of researchers sailed
to the northwestern Pacific and spread 1,000 pounds of a liquid iron
compound over phytoplankton growing across 30 square miles of the open
ocean. The iron quickly created a thick mat of one-celled diatoms that
spread widely and absorbed 4 million pounds of carbon from the carbon
dioxide in the atmosphere, their calculations showed.
The experiment's success, reported at the time in four articles in the
journal Nature, has been followed with a dozen more large-scale
experiments by international teams of researchers who also reported
similar success.
Industries also started supporting experiments in what some critics
term "geoengineering." By supporting the concept, industries that emit
carbon dioxide in massive quantities through the burning of fossil
fuels believe they could earn "carbon credits" under the rules of many
nations.
The scientists raising the new issue sailed their research ship into
the northeastern Pacific where the ocean is rich in nutrients but poor
in iron, and pumped gallons of the ocean water into shipboard
laboratory tanks containing a widespread species of the phytoplankton
variety called Pseudonizschia. The species is known to produce domoic
acid, a toxin that can cause fatal nerve damage to seabirds and marine
mammals. It is also a major cause of human shellfish poisoning in
coastal waters.
Increased hazard
Adding an iron compound to the plankton caused the one-celled diatoms
to bloom heavily, but also greatly increased the amount of the toxin
produced in every single plant cell, the researchers found. And that,
in turn, means the toxin would spread more widely through the food web
of the ocean, the scientists maintained.
The research was funded by the National Science Foundation and the
Department of Energy.
"This possibility of producing a widespread toxin into the plankton of
the open ocean needs to be looked at very carefully before any large-
scale iron enrichment starts," said William P. Cochlan, a biological
oceanographer and marine ecologist at San Francisco State University's
Romberg Tiburon Center for Environmental Studies, who was on the
research team.
In interviews Monday, both Coale and Johnson, who led the first
experiment two decades ago, agreed that the new findings were valid
and important.
The problem of a toxin that threatens marine life must indeed be
weighed before any major plankton fertilization projects are launched,
the two scientists said.
"It's a great paper, but I remain a proponent of iron fertilization -
if it does indeed work on a very large scale - because it's the only
process that takes carbon dioxide out of the atmosphere," Johnson
said.
Coale said that "in some cases" his colleagues had also seen large
increases in the domoic acid toxin during their own earlier iron
fertilization experiments.
But he added: "I'm with Ken (Johnson) on this. We do need to explore
all the options and their consequences. My feeling is that iron
fertilization is no magic bullet, but it may need to be considered
among a large portfolio of carbon sequestration efforts."
E-mail David Perlman at [email protected].
http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2010/03/16/MN2C1CE0E4.DTL
On Mar 15, 9:05 pm, [email protected] wrote:
> Hello, Dan,
>
> I think we are in really deep water here. The marine scientists are just
> beginning to understand what's going on with open ocean phytoplankton. I
> was captivated by work being done by Irina Marinov and others at Woods Hole
> while she was a post-doc there, showing how other nutrients have a critical
> role in how iron is used. She is now at U. of Penn.
> _http://www.sas.upenn.edu/earth/marinov_r.html_(http://www.sas.upenn.edu/earth/marinov_r.html)
>
> I think to really understand the goings-on with phytoplankton, it would be
> good to talk with someone like her or dig into the recent literature. I
> think she was involved (not sure) with showing how the toxic blooms are
> connected with insufficient dissolved silica in the water. Natural surface
> fertilization usually involves application of iron-rich silica, say from dust
> storms or colloidal minerals from glaciers. (That's my understanding,
> could be way off) Silica shifts the productivity into diatoms which are the
> bottom rung of the ocean food chain. As far as I know, no OIF experiments
> involved adding finely-divided silica with the iron.
>
> I am very concerned about the acidification of sea water since silica
> solubility decreases with decreasing pH. I wonder if this has a bearing on
> the
> falling oxygen concentration in sea water and the more frequent hypoxia
> events in recent decades.
>
> My personal view is that ocean productivity is the real key to practical
> geoengineering by way of CO2 removal. But you will find many that would
> disagree.
>
> Ernie Rogers
>
> In a message dated 3/15/2010 3:15:42 P.M. Mountain Daylight Time,
>
> [email protected] writes:
>
> A PNAS paper was released today commenting on studies finding domoic
> acid in some of the samples from previous OIF projects.
>
> A variety of articles have
> commented.http://www.nature.com/news/2010/100315/full/news.2010.124.htmlhttp://www.nytimes.com/2010/03/16/science/16obiron.htmlhttp://news.discovery.com/earth/geoengineering-carbon-sequestration-p...
> nkton.html
>
> I commented here:http://climos.com/note_detail.php?pid=174
>
> A PNAS paper released today which looks at domoic acid (DA) production
> in past OIF experiments has concluded that DA was increased in some of
> the projects. Though the conclusions from the paper itself were
> relatively conservative...
>
> "Although there remain uncertainties in extrapolating our results to
> large oceanic scales, the findings establish potential consequences
> for developing toxic phytoplankton blooms in pelagic ecosystems, which
> so far have not been adequately investigated."
>
> Headlines have ranged from the dramatic "Ocean Geoengineering Scheme
> May Prove Lethal", and at the NY Times, the oddly phrased, "A Risk of
> Poisoning the Deepest Wells" to the more subdued, "Carbon-capture
> scheme could cause toxic blooms".
>
> All fail to explore the obvious. Namely, that phytoplankton underpin
> open ocean productivity, that this productivity relies on iron, and
> that when iron-fed naturally occurring blooms happen, they likely
> favor--in certain regions--Pseudonitzschia or other DA producers. In
> short, we know that the availability of iron drives much of the
> oceanic carbon cycle. If DA is produced by artificially stimulated
> OIF blooms, it is likely produced during natural ones as well.
>
> Moving forward, we need to understand exactly how deep-ocean
> phytoplankton respond to iron--be it naturally or artificially
> supplied, whether and in what situations DA is produced, and how the
> ecosystem is or is not already adapted to this. If it occurs
> naturally, are organisms that live there used to blooms containing
> DA? In past climate cycles, when productivity in the deep ocean was
> much greater, was DA characteristic as well?
>
> These are questions that remain unresolved and need well defined
> research programs to address.
>
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