Algae First To Recover After Asteroid Strike

pickens writes "The asteroid that impacted earth 65 million years ago killed off dinosaurs, but microalgae bounced back from the global extinction in about 100 years or less. Julio Sepúlveda, a geochemist at MIT, studied the molecular remains of microorganisms by extracting organic residues from rocks dated to the K-T extinction (in this research referred to as Cretaceous-Paleogene), and his results show that the ocean algae community greatly shrunk in size but only for about a century. 'We found that primary production in this part of the ocean recovered extremely rapidly after the impact,' says Julio Sepúlveda. Algae leave certain signatures of organic compounds and isotopes of carbon and nitrogen; bacteria leave different signatures. In the earliest layers after the asteroid impact, the researchers found much evidence for bacteria but little for algae, suggesting that right after the impact, algae production was greatly reduced. But the chemical signs of algae start to increase immediately above this layer. A full recovery of the ocean ecosystem probably took about a million years, but the quick rebound of photosynthesizing algae seems to confirm models that suggest the impact delivered a swift, abrupt blow to the Earth's environment."

Comments

Re:If there is another strike

[eldavojohn]

You may want to welcome them already. Recent research shows now that phytoplankton were/are consumers of poisonous ammonia in our oceans. And they produced out of it what plants crave. 'Lytes! No wait, I mean Nitrogen. I'm not a biologist but this latest research seems to imply that our designation of bacterial nitrifiers as most important to the nitrogen cycle is wrong and should be given to Archaea. From that research:

The new experiments show that the organism can survive on a mere whiff of ammonia - 10 nanomolar concentration, equivalent to a teaspoon of ammonia salt in 10 million gallons of water. In the deep ocean there is no light and little carbon, so this trace amount of ammonia is the organism's only source of energy.

So I wouldn't be surprised that phytoplankton would be the first to recover after an asteroid strike. Not much needed for them to survive. Apparently if all of this is true, a lot of ecology is going to be rewritten. Exciting times if you're in that field I guess.

Re:My magical toilet

[Anonymous Coward]

Pro Tip:

Close the lid when you aren't using it. Keeps the sun out, and the algae dead.

Re:Scalpel, please

[Convector]

What they're saying is that it takes algae 100 years to recover from this kind of event, no matter how long ago that actually happened. If the impact were to happen right now, it would take 100 years to recover. If it happened 65 Mya, it takes 100 years to recover. We just don't know the start and end times that well, so they can't say the recovery was done by 65.0001 Mya. Another example is the formation of the solar system. The half life of Al-26 is only about 0.7 million years. So we know the majority of the Al-26 was gone by 5 My after the formation of CAIs' (commonly taken as age 0 for the solar system). We just don't know that date very well. It's about 4.6 Gya, but we can't say that the Al-26 was gone by 4.595 Gya. We may know that this impact crater on Mars is 10 My younger than another, but don't know either date well enough to say impact A happened at 4.11 Gya and impact B happened at 4.10 Gya. Could be 4.15 and 4.14, for example, but we know the spacing.