"Is Coral Growth Affected By Increasing Concentrations Of Iron or CO2 In Sea Water?"

[HighlandReefer]

2008 Student Research Conference:
21st Annual Undergraduate and 6th Annual Graduate Research Conference

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Is Coral Growth Affected By Increasing Concentrations Of Iron or CO2 In Sea Water?
Josh W. Akers
Dr. George Shinn, Faculty Mentor

In the face of declining coral populations due to global warming, biologists are searching for ways to artificially enhance coral growth rates. My experiments, conducted at the World Aquarium in St. Louis, Missouri, were designed to test the hypothesis that growth of reef corals can be enhanced by "fertilizing" them with iron. 110 mL of "aquarium iron" was added weekly to a 1,100 gallon tank containing three coral species (leather, button, and tree corals). The height, width, and depth of each colony were measured every other weekday and colony volumes were calculated. Gaseous CO2 was continuously bubbled into a 125 gallon tank containing these same species to test the effects of increasing CO2. A 250 gallon control tank received neither additional iron or CO2. Over the ten week period of the study, the added iron enhanced the growth of the leather and tree corals, only. Increased CO2 showed no affect.

http://src.truman.edu/browse/display.asp?abs_id=1735&year=2008

[glassbox-design]

Thanks for sharing :thumbsup:

[Randy Holmes-Farley]

Interesting, but I'd be wary since we cannot see any details and do not know if the control tank was properly controlled for lighting, flow, feeding, etc. We do not even know what form of iron was used, some of which supply other things, like organic compounds. :)

[HighlandReefer]

"Response of a scleractinian coral, Stylophora pistillata, to iron and nitrate enrichment": http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8F-42YF4NN-7&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=8ccfb0daba673ed35440f0fd07268aea

[Letmegrow]

I am from St. Louis.

The World Aquarium is always pumping out some nonsense.

They also claimed that Hypersalinity made corals spawn and the larve settle out of the planktonic stage 300% faster than in the wild and the corals grew faster in the aquarium there after at speeds up to 500% faster.

The reality was they killed EVERY coral in the tank, and when an employee replaced all the corals in the tank they said "Wow !! Look at all these new corals we grew!!"


It is barely worth my breath to say this article is bunk, but it is.

[Letmegrow]

Actually, to be fair I will personally go to the World Aquarium with an outlined interview for Dr. George Shinn and Josh W. Akers
(if he is still there).

You guys write it up and I will pay the General Admission of $12 to the museum plus the $6 to the World Aquarium.
http://www.citymuseum.org/admission.html

I can record it for a pod cast or I can take pictures and do it all in written form.

[HighlandReefer]

"Phase Shift from a Coral to a Corallimorph-Dominated Reef Associated with a Shipwreck on Palmyra Atoll": http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2500175

I have spent a couple days reading various articles, research papers, etc which were about the relationship of iron in our oceans. The above three articles seemed to stand out above the others. From what I have read, I would conclude that increasing iron concentrations does have an affect on many organisms in the oceans. There have been iron correlations to diatoms, bacteria, microalgae, macroalgae, anemones & corals. In some cases increased iron concentrations has caused algae & bacterial blooms. In other cases increased iron concentrations has caused certain anemones & corals to increase in reproduction & growth. That said, the affects of increasing iron concentrations seems to be species specific.

[geoxman]

Ha ha! that is too funny that they call themselves a "world aquarium"?? That place is a dump. They have some dirty FW tanks and a really dirty Shark cylinder, with a few other dismal tanks-with almost zero corals??
I do not know anything about iron but I would not take any advice from the Saint Louis City Museum, as letmegrow stated, they throw out crazy info. I am also from STL

[glassbox-design]

<a href=showthread.php?s=&postid=13846704#post13846704 target=_blank>Originally posted</a> by HighlandReefer
The affects of increasing iron concentrations seems to be species specific.

Said very well. Randy pointed out some obvious & important points, that I fear may not be addressed... If anyone has additional information on this "oral paper" or the conference please do share.

[HighlandReefer]

It seems that many researchers think that adding iron to the oceans will help global warming. One group came close to getting enough money to spread large quanitties of iron in certain areas of the ocean as a research prodject. It would be interesting to see what happens if they do get funded, but I have some serious reservations about the negative impacts that may occur in those areas, based on some prior research. :)

[billsreef]

The idea to adding iron to the ocean is to stimulate plankton blooms that would theoretically remove large quanitities of CO2 from the atmosphere. Google IronEx II.

[buddah001]

I think I remember seeing a thread here one time about a guy from china or asia sonewhere and he had a bunch of nails that were rusted in some sort of reactor looked homemade. Supposedly he ran his tank water through it. I gues he was dosing Iron.

[mesocosm]

Greetings All !


<a href=showthread.php?s=&postid=13846704#post13846704 target=_blank>Originally posted</a> by HighlandReefer
... the affects of increasing iron concentrations seems to be species specific. The metabolic behavior of marine microorganisms can be significantly influenced by iron enrichment. To the extent that the metabolic behavior of microorganisms affects corals (... like the metabolic behavior of the microorganisms known as zooxanthellae ... or the metabolic behavior of bacteria engaged in nitrification & denitrification ...) I suspect that we're not talking about a "species specific" situation.

JMO ... :D



<a href=showthread.php?s=&postid=13855531#post13855531 target=_blank>Originally posted</a> by billsreef
... Google IronEx II. Indeed ... :thumbsup: Folks might consider starting with this one ...

Cochland, W. P. 2001. The heterotrophic bacterial response during a mesoscale iron enrichment experiment (IronEx II) in the eastern Equatorial Pacific Ocean. Limnol. Oceanogr. 46: 428–435.
http://aslo.org/lo/toc/vol_46/issue_2/0428.pdf

From the article ...
"These results demonstrate that iron addition to this high-nitrate, low-chlorophyll region affects both autotrophic and heterotrophic microorganisms ... ."What other "regions" might be high NO3 and low chlorophyll? ... ;)



And more recently ...

Arrieta, Jesús M., Markus G. Weinbauer, Carolien Lute, and Gerhard J. Herndl. Response of bacterioplankton to iron fertilization in the Southern Ocean. Limnol. Oceanogr., 49(3), 2004, 799–808.
http://aslo.org/lo/toc/vol_49/issue_3/0799.pdf

From the article ...
"Besides the peaks in leucine and thymidine incorporation following Fe release, bacterial production was not significantly higher inside the patch than outside, suggesting direct limitation of bacterial growth by Fe."Strange that everyone is so obsessed with C limitation, isn't it? :lol:


Also from the article ...
"No major changes in response to Fe fertilization were detected in the phylogenetic composition of the bacterioplankton community, as determined by 16S rDNA fingerprinting, indicating a remarkable adaptation of the bacterioplankton community to episodic iron inputs."Equally strange is the obsession with biomass shifts (the dreaded, illusory 'monoculture'), while ignoring the fundamental metabolic shifts. After all, it's the metabolic processes that we're after ...

... isn't it? :lol:




JMO
:thumbsup:

[HighlandReefer]

From my understanding, it is harder for bacteria to brake down more complicated forms of carbon molecules (ie. alcohols, starches, sugars). If given the choice, they will pick the least complicated forms. Increased levels of iron aids in the brake down of the more complicated molecules. Some bacteria can not brake down these larger molecules, but can actually share from bacteria that can brake down the larger molecules. From this I would conclude that the order of easiest to hardest for brake down by bacteria for the carbon sources commonly dosed would be:
1) vinegar - easiest
2) Sugar
3) Vodka - hardest

I would assume that if you are dosing a carbon source, that adding additional iron may benefit this process. I would also assume that depending on the type of bacteria present in mucal layer around the zooxanthellae, that in many cases increased iron will also increase their production.

If I am correct in my assumptions, then perhaps this is why dosing vinegar seems to have more cases of bacterial blooms (mats). :)

[HighlandReefer]

I am dosing vinegar at 75 ml vinegar/3 tsps kalk/ 1 gallon of rodi. I am dosing iron at 10 ml per 145 g. of water volume of Randy's mix. Chaeto was not able to compete with the bacteria, IMHO, until I started to dose the iron. Now it is competing well. Bacterial growth was not apparent at zero nitrates & phosphates while I was dosing the vinegar. Bacterial growth on the walls of my refugium increased dramatically once I started dosing iron (maybe a coincidence). I have had Kenya tree in my system for 7 months, with little growth. Now there has been a definite increase in growth since I started dosing iron. My Xenia was not growing at all once my system hit zero nitrates & phosphates. Since I started dosing iron, I have noticed that it has been increasing in mass significantly. It does not grow as tall, but does branch & multiply much better.

[mesocosm]

Greetings All !


<a href=showthread.php?s=&postid=13857650#post13857650 target=_blank>Originally posted</a> by HighlandReefer ... it is harder for bacteria to brake down more complicated forms of carbon molecules ... As a general rule, simple sugars (short-chain sugar molecules) are more easily catabolized (... 'broken down' ...) than complex sugars (long-chain sugar molecules). It's not a function of how "complicated" the molecule is, it's all about whether or not the bacteria is able to produce an enzyme that is capable of splitting the bonds that hold the molecule together. Alcohols, starches, and sugars comprise a wide diversity of compounds, many of which are easily catabolized, and many of which are not so easily catabolized ("refractory"). The length of time required to break down "alcohols, starches, sugars" in natural marine ecosystems ranges from hours ... to centuries.



<a href=showthread.php?s=&postid=13857650#post13857650 target=_blank>Originally posted</a> by HighlandReefer ... Increased levels of iron aids in the brake down of the more complicated molecules ... While Fe is a potentially significant participant in the reduction reactions that produce energy within bacteria (like the reduction of NO3 into N2), the actual catalysis is performed by enzymes.



<a href=showthread.php?s=&postid=13857650#post13857650 target=_blank>Originally posted</a> by HighlandReefer ... the order of easiest to hardest for brake down by bacteria for the carbon sources commonly dosed would be ... Not necessarily ... much depends on not only the specific enzymes that a given bacteria can synthesize, but also the micro-environmental conditions that are present. But yes, simple sugars are typically more readily catabolized (and metabolized) than is ethanol.

The designation of vinegar (acetic acid) as a carbon source, while technically defensible, misses the point ... acetic acid is relatively unimportant as a carbon source. The derivatives of acetic acid are what matter, not the acetic acid itself acting as a carbon source. The salts and esters of acetic acid (derivatives known generally as acetates) are critical electron donors. VSV formulae are more accurately described not as a mixture of 3 different carbon sources, but rather as a mixture of 2 different carbon sources (ethanol & simple sugars) and an electron donor (derived from acetic acid). It is this presence of an electron donor that explains why VSV mixtures typically stimulate more rapid bacterial growth and more rapid uptake (... and utilization ..) of nutrients compared against either sugar or vodka (ethanol) dosed in isolation.

A word about electron donors ... the biogeochemical pathways involved with bacterial growth and nutrient uptake are basically (but not exclusively) a series of oxidation and reduction reactions. Oxidation and reduction reactions are (... all the biochemists out there please forgive me for this over-simplication ...) essentially the shuffling of electrons between atoms and compounds. Having a compound that feeds electrons into this "shuffling" process (... i.e., an electron donor ...) can significantly increase the velocity of the reactions. For more on this, check out the V(max) equations by Monad ("Monad Kinetics"). The concentration of electron donors is a critical variable in the empirical description of bacterial biogeochemical processes.



<a href=showthread.php?s=&postid=13857650#post13857650 target=_blank>Originally posted</a> by HighlandReefer ... I would assume that if you are dosing a carbon source, that adding additional iron may benefit this process. I would also assume that depending on the type of bacteria present in mucal layer around the zooxanthellae, that in many cases increased iron will also increase their production. ... These are excellent assumptions ... nice. :thumbsup:



glassbox-design, this one's for you ...

Obernosterer, Ingrid, and Ronald Benner. Competition between biological and photochemical processes in the mineralization of dissolved organic carbon. Limnol. Oceanogr., 49(1), 2004, 117–124.



HTH
:D

[HighlandReefer]

Many thanks Mesocosm for taking the time to explain this to me in further detail. It is wonderful to be enlightened. :D

[HighlandReefer]

In the absence of added carbon sources (vodka or sugar), vinegar would serve as a critical electron donor for the normal DOC found in an aquarium system? If an excess of vinegar is added over what is needed to utilize the standard DOC found in an aquarium system, what happens to the excess vinegar (electron donor) & what affect would one expect it to have on the aquarium system?

[Randy Holmes-Farley]

Acetate as an electron donor for DOC? Not sure what you mean. Acetate is an electron donor as it is oxidized with O2 (or nitrate in sand beds). It provides energy as do other organic compounds that are metabolized. The energy you get may be used for many purposes. I'm not sure of the basis of mesocosms suggestion that sucrose and ethanol would not be used in a similar way (I expect some or even much of it is used similarly), but certainly some of it may be used directly to build other organic molecules. I also expect that is the fate of some of the acetate. Perhaps there is a higher portion of acetate oxidized to CO2 than the other 2 organics, but I've not seen data suggesting that would happen in our complex systems.

As to DOC in the tank, some may be suitable as building blocks of new bacterial bodies, but some will not be, and much of it isn't going to be taken up even if it were suitable.