Whale Poop

Earlier this week we talked about how to use whale snot for science.

I especially enjoyed blog bff Scicurious's take on the study:

Budgetary requirement: $5000 for series of expensive remote control helicopters.
Source: Toys R Us.
Justification: Need something that can fly close to a whale and collect snot for measurement. Also, this is the only kind that comes in red, and the gunmetal grey ones suck.

This day, however, we will travel farther, er, south. Through the mouth, down the esophagus, into the stomach, detour through the intestines, take a left at the sphincter, but, what, what's that blocking your way?

It's whale poop, friend.

And it's nature's answer to a really important problem. At least if you're a krill: how to get more iron into your diet.

So here's the basic idea: phytoplankton bloom in surface waters that contain lots of water-soluble iron. Krill eat the phytoplankton and take in all that iron. Baleen whales eat krill, and likewise take in all that iron. It's like recycling, only better, because instead of getting 5 cents back for an iron bottle, you're getting a tasty meal. Then the whale poops, and it acts as a fertilizer, releasing all that iron back into the water. It's like the circle of life.

I feel for the poor, poor grad student who had to collect and analyze 26 whale poop samples (blue, pygmy blue, humpback, and fin whales).

Why should you care? Because the great whales are low in numbers. Which means less whale poop. And therefore less iron in the water, so less phytoplankton, and less krill. The researchers estimate the current population of krill in Southern Ocean (i.e. around Antarctica) may be as little as 20% of its pre-1980 numbers. And since krill is an indication of the presence of phytoplankton, we can assume a similar reduction in phytoplankton floating around down there.

And what do phytoplankton do? Like any other plant, they do photosynthesis, which means they remove carbon dioxide from the atmosphere. That's right, the same carbon dioxide that is so important in global warming.

Moral of the story? Save the whales to help reduce global warming.

(h/t Discoblog)

Nicol, S., Bowie, A., Jarman, S., Lannuzel, D., Meiners, K., & van der Merwe, P. (2010). Southern Ocean iron fertilization by baleen whales and Antarctic krill Fish and Fisheries DOI: 10.1111/j.1467-2979.2010.00356.x