Fish Work as Anti-terror Agents

sdriver writes "San Francisco's bluegills went to work about a month ago, guarding the drinking water of more than 1 million people from substances such as cyanide, diesel fuel, mercury and pesticides. "There's no known manmade sensor that can do the same job as the bluegill." The New York City Department of Environmental Protection reported at least one instance in which the system caught a toxin before it made it into the water supply."

Comments

Animals as agents of terror.

[hullabalucination]

At the other end of the issue, we've used animals as agents of destruction in some pretty weird ways. Probably everybody here has heard of the U.S. Navy's experiments using dolphins or porpoises as a delivery system for below-the-water-line bombs targeting ships. The weirdest I've ever heard of was the Army's Bat Bomb project during WWII:

http://en.wikipedia.org/wiki/Bat_bomb

Does anyone here watch the History Channel (North America)? Didn't they run a documentary on this project a couple of years ago?

* * * * *

My goal is to someday be the person my dog thinks I am.
--Unknown

The idea's not exactly new.

[techno-vampire]

Using animals as sensors to detect contaminants isn't exactly a new idea. Coal miners have been using canaries to detect coal damp and other noxious gases for at least a century. The only new thing is using fish instead of birds. Nice idea, though, and a lot more cost effective than trying to design something sensative enough to be useful.

"Fishkill" test

[Barbarian]

This is also pretty standard for treated industrial wastewater--take a sample from the outflow on a regular basis, send it to a lab, and they stick fish in it and see how many die within 24 hours. Some setups even have a small side stream so that you can get results in real time.

Re:Not likely method

[arivanov]

Using it as a poison does not require any technical knowledge and is quite effective. While not as poisonous as some mercury compounds or pesticides, it is still poisonous enough to have effect. In addition to that, the howling of the media about Pu discovered in drinking water will provide the terrorists with what they want even if nobody dies. Go and try to explain Joe Average that the concentration is so low that it will not do a thing. As far as he is concerned it is plutonium. Scary stuff.

On the subject of the article - many phosphorganic, pyrethroids and other insecticides are temperature specific. Many will kill fish and insects only under specific temperature. They are harmless to warm blooded animals for this exact reason - the target is outside the optimal thermal range. Now, I have not followed advanced in this area, but what exactly will these fish do if someone pours a tanker of something that is the opposite in thermal specificity. Something harmless for coldblooded animals which kills warm blooded only?

Just a new application

[tomatoguy]

of a technique used by water-testing labs. Trout and Daphnia are used in the lab I consulted to once. For things with a higher ppm range trout were used, and for lower ppm concentrations Daphia (which are barely naked-eye visible) are used. The waterborne equivalent of canaries in coal mines.

very difficult to make that effective

[YesIAmAScript]

Plutonium is toxic, that's true.

But the descriptions you hear all the time about how one gram can kill a bazillion people assumes that each person gets exactly a lethal dose and no more.

In reality, this is difficult to do. Plutonium, for example, is not soluble in water and is very heavy. So distributing it through the water supply would be very difficult.

If you drop a bit in the water supply, it'll just sink to the bottom in the first eddy it reaches and sit there, killing only things that come near it instead of the intended targets. It might kill nothing except a few rats.

http://www.llnl.gov/csts/publications/sutcliffe/

Re:Not the first

[ForestGrump]

Slightly off topic, but a related story.

I took an environmental law class once, and the guy who taught it used to work county health or something.

In California, there are a few ways of determining if somethning is toxic, and one of the ways is to put the suspected agent into a fish tank with an "indicator species" of fish and wait a few days to see if the fish live or die. If the fish die, then the suspected agent is thus toxic.

Well, one time he was infront of a judge explaining the test, and presenting that the fish died.
The judge then asked if the were any of these fish wild in the county.
No, there are none of these fish wild in the county.
Then why do we care about this test then?

Well, some people just don't understand the importance of indicator species.

Grump

Re:Really, and what about a mass spectrometer?

[KillerBob]

The problem with a spectrometer is that the more you have in the substance you're testing, the harder it is to detect a single substance. It's not like every chemical has a single line that shows up on a spectrometer scan... actually, everything has several lines that show up. The more complex a substance is (and the heavier the atoms that make it up), the more lines appear. Pure Iron (Fe), for example, has 43 lines that show up on its spectrum. And drinking water isn't pure H2O. Not by a long shot... pure H2O tastes soapy, bland. Like there's something wrong with it. Our tap water has lots of stuff in it already that isn't harmful. Mineral content, and additives like chlorine and fluoride.

Now... they could establish a baseline and subtract that, but there's so much stuff already in drinking water that you'd probably have a hard time telling one thing from the next. What you think could be cyanide may actually be a higher than normal silica content. There's really no way to be sure that what you're seeing on a spectrometer is dangerous without doing a proper series of tests on it, and there's no way to do those tests fast enough to cut off the water supply. The result is that you would need to set the sensitivity *way* too high and end up getting a lot of false positives... when you're dealing with contaminated water supply, a false positive is far more desirable than a false negative.

But here's a system that costs a *lot* less to implement, and because you're using living beings that are much more sensitive to poisons than humans are, you'll see the effect of a toxin long before the concentration is high enough to seriously harm a human.

Absurd, exaggerated claims

[nasor]

"There's no known manmade sensor that can do the same job as the bluegill."

This claim is absurd on its face. Who told him that? The guy who sold him the fish? He's obviously not an analytical chemist. Things like high-resolution mass spectrometry can detect cyanide, diesel fuel, mercury and pesticides at parts-per-trillion levels, far lower than anything that could ever possibly have any sort of detectible biological effect on a fish. There is no way that a fish is going to be effected by a nanogram/liter concentration of mercury, but a good mass spec would be able to see it.