Hungry Crustaceans Eat Climate Change Experiment

Earlier this month, an expedition fertilized 300 square kilometers of the Atlantic Ocean with six metric tons of dissolved iron. This triggered a bloom of phytoplankton, which doubled their biomass within two weeks by taking in carbon dioxide from the seawater. The dead phytoplankton were then expected to sink to the ocean bed, dragging carbon along with them. Instead, the experiment turned into an example of how the food chain works, as the bloom was eaten by a swarm of hungry copepods. The huge swarm of copepods were in turn eaten by larger crustaceans called amphipods, which are often eaten by squid and whales. "I think we are seeing the last gasps of ocean iron fertilization as a carbon storage strategy," says Ken Caldeira of the Carnegie Institution at Stanford University. While the experiment failed to show ocean fertilization as a viable carbon storage strategy, it has pushed the old "My dog ate my homework" excuse to an unprecedented level.

Comments

Why is this a problem?

[wiredog]

The carbon is still being sequestered, just not where they expected it.

Not for carbon sequestration, but how about food?

[PeterM from Berkeley]

From the results of the experiment, apparently it won't work as a means to sequester carbon.

However, what if we can use this to improve the productivity of the ocean in general? Might the increased amount of biomass serve to improve fisheries? I.e., if there's more food all the way up the food chain, can't we eat more fish? It's a hungry planet and many fisheries have been depleted....

--PeterM

Re:So...

[32771]

To continue this path, what happens to the dissolved CO2 at those depths:

"Another process, called "the biological pump," transfers CO2 from the ocean's surface to its depths. Warm waters at the surface can hold much less CO2 than can cold waters in the deep. "This is the 'soda bottle on a warm day' effect," says Agassiz professor of biological oceanography James McCarthy, "and is not unique to carbon dioxide; it applies to all gases dissolved in water. There is a higher capacity to hold a gas with a lower temperature than with a higher temperature." This means that when deep ocean waters rise to the surface as part of normal ocean-circulation patterns, the water heats up and actually releases CO2."

from here,
http://harvardmagazine.com/2002/11/the-ocean-carbon-cycle.html

So this is a temporary storage solution and the fertilizer might speed up the process but the CO2 is at best dissolved it seems.

I guess CO2 storage could be really helped by dumping CaOH or something like that into the ocean just where this should come from I wonder.

Re:Well it sounds better than

[Anonymous Coward]

I don't even see how this yielded negative results. What did they expect would happen? I mean the summary says they expected the dead phytoplankton to sink to the bottom of the ocean. Ok, so instead it was eaten, how is that negative? Isn't the carbon still sequestered away inside the crustaceans? If so, how is this negative or a failure again?

There has to be something missing here like that the crustaceans suddenly started flying and farting...or something. Otherwise, it looks like it was a win and nobody has recognized it as such.

Anyone?

Re:Well it sounds better than

[Anonymous Coward]

Dead phytoplankton sinking to the bottom = capturing carbon
 
Creating a chain reaction in the food-chain = destabilizing the ecosystem
 
This isn't good because you're directly increasing the number of predators without increasing their pray. As a result, these hungry predators will create a collapse of pray since the experiment was a one-off. Look at it like this (simplistic, I know): the number of lions and zebras in Africa are in a dynamic balance. One day a group of researchers comes in and add a shitload of Wildebeests. Number of lions increase as their diet became richer. The extra Wildebeests are removed by the lions, the next season there are too many lions per zebra. Bye bye zebras.

Re:Well it sounds better than

[geobeck]

According to a recent study that I'm too lazy to google for (and is only a single study, so it's not proof of anything), fish excrement contains a significant amount of calcium carbonate.

If this CaCO3 sinks to the bottom before it dissolves, it would sequester the carbon. If, however, it dissolves before it sinks, it releases the carbon right back into the water. The fate of the fish excrement was beyond the scope of the study.

So a significant amount of carbon may or may not be sequestered by the fish that prey on the plankton that capture the carbon, while a significant amount is caught up in the biomass of the fish.

However, with rampant overfishing, including use of illegal catch-em-all nets in "protected" areas, which is just about impossible to police, all of the carbon that becomes part of fish biomass will end up back in the atmosphere after passing through someone's digestive system.

But, if somehow fishermen around the world can be convinced to use iron fertilization as part of a comprehensive aquaculture system, and actually increase the global fish biomass...

Nah, you'll never get enough people cooperating to make that happen.