Killer Algae A Key Player In Mass Extinctions

[BlackZodiac]

by Staff Writers
Boulder CO (SPX) Oct 22, 2009

Supervolcanoes and cosmic impacts get all the terrible glory for causing mass extinctions
, but a new theory suggests lowly algae may be the killer behind the world's great species annihilations.

Today, just about anywhere there is water, there can be toxic algae. The microscopic plants usually exist in small concentrations, but a sudden warming in the water or an injection of dust or sediment from land can trigger a bloom that kills thousands of fish, poisons shellfish, or even humans.

James Castle and John Rodgers of Clemson University think the same thing happened during the five largest mass extinctions in Earth's history. Each time a large die off occurred, they found a spike in the number of fossil algae mats called stromatolites strewn around the planet. Castle will be presenting the research on Monday, 19 October at the annual meeting of the Geological Society of American in Portland, Oregon.

"If you go through theories of mass extinctions, there are always some unanswered questions," Castle said. "For example, an impact - how does that cause species to go extinct? Is it climate change, dust in the atmosphere? It's probably not going to kill off all these species on its own."

But as the nutrient-rich fallout from the disaster lands in the water, it becomes food for algae. They explode in population, releasing chemicals that can act as anything from skin irritants to potent neurotoxins. Plants on land can pick up the compounds in their roots, and pass them on to herbivorous animals.

If the theory is right, it answers a lot of questions about how species died off in the ancient world. It also raises concerns for how today's algae may damage the ecosystem in a warmer world.

"Algae growth is favored by warmer temperatures," Castle said. "You get accelerated metabolism and reproduction of these organisms, and the effect appears to be enhanced for species of toxin-producing cyanobacteria."

He added that toxic algae in the United States appear to be migrating slowly northward through the country's ponds and lakes, and along the coast as temperatures creep upward. Their expanding range portends a host of problems for fish and wildlife, but also for humans, as algae increasingly invade reservoirs and other sources of drinking water.

[DoctorZoidberg]

sooo i gues we need to start stocking up on bottled water now then ...... so im guessing it would be more stupid to take a drink of water from a pond in the south than the north? the way it looks is that if we get any more global warming we are going to kill our selfs for many many years ... ..... im sure we can filter out Algae rite? to a certain extent?

[BlackZodiac]

Not that easy, the water ended up producing sulfuric gasses.

[DoctorZoidberg]

my water gives out a little sulfur as well... but i still drink it and is just fine, is sulfur that horribley bad for us? or are you meaning the amount of gasses will ruin the enviroment ....?

[Pyrohippie]

I dont think it would be to enjoyable having chunks of sulfer deposits in your stomuch. Who knows though.

[Kaizer Soze]

I'm honestly surprised. Something so small as algae can cause all this damage to ecosystems, and play a part in mass extinctions...Woah. I wonder what would happen with all the leftist environmental fools should an explosion of algae occur in a lake somewhere, and we decide to use algecide to kill it off so it doesn't harm the fish in the lake.

@Dr.Z - I don't think it's saying anything about whether this algae will affect your tapwater. But if it gets into a reservoir or source of water and starts producing all these chemicals, then there will be a major problem.

Tapwater is fine. No need to spend extra money on bottled water. I swear bottled water tastes the same as tap water in some cases, if not it tastes bland as...bland. There's so few heavy metals in a given amount of tapwater that you'd have to drink an astronomically high amount in order for it to kill you. Same with salts and that stuff too.

Bottled water is convenient, but at the same time you should just get a waterbottle and fill it from the tap, dammit.

[Xon]

Its just another fear tactic. You can take any one thing and if you have to much of it, it will destroy the environment.