aluminum cans on the ocean floor

[StianM]

Cans with coke last way past the exspiery date.

I think coke is causing more corotion than sea water

[SamSam]

If the cans didn't corrode quickly I would think that bottom trawlers would haul up a lot of them, possibly to the point of one bin for the fish and another for the scrap aluminum.

[sjo hest]

I just received an email from Cassandra Harper of the Water Resource Center, EPA, who sent along several helpful websites. According to the University of Florida AFAS Extension service, the issue is exposure to UV, so depth is key. Their timeline for degradation lists aluminum cans as lasting nearly 200 years (I'd heard 180 before). Far more durable are glass bottles (700), plastic bottles (450) and non-biodegradable diposable diapers (400). Regular tin cans degrade much more quickly, of course, (but can last several decades) and on the other end, plywood lasts two years, cotton rope one year, cardboard boxes a month or two, and paper towels are gone in a flash. The website is http://stjohns.ifas.ufl.edu/Sea/marine_debris.html
Interesting stuff!

[Roly]

I cannot understand why any human with a modicum of asthetic apreciation would want to biff their slow or toxic degrading trash in the ocean. Pox on all the advocates.
Obviously they don't, or haven't, been snorkling lately;Or don't give a rats ass.

[Poida]

Don't yer just love geeks and their fancy figures sjo.

So if I find an aluminium can half corroded on the ocean floor, it's got to be at least 100 years old.

Roly no one is advocating we throw cans in the ocean, we were just debating how long they would last if we did.

Poida

[sjo hest]

Yes, Roly, the whole subject came up because I indeed "give a rat's ass." I was teaching 5th graders a "leave no trace" outdoor ethics course and was emphasizing how long different items could trash up the environment if left. I quoted what I'd heard, that an aluminum can could last up to 180 years on the ocean floor, and I was later challenged by an adult who believed that couldn't possibly be true. Thus I asked this forum as well as other sources for confirmation. Answers have been varied and extremely interesting!

[Roly]

Good to hear you guys want to stand up and be counted.No target intended,
just general borax!

I would be curious to the rise in Al,Hg,trace metals etc in fish over time.All those dissolved salts/ions going into the food chain.My daughter tells me it is largely location dependent. Minimato etc.


Amended:

Pox on all the advocates.
Obviously they don't, or haven't, been snorkling lately;Or don't give a rats ass

[charmc]

Originally Posted by sjo hest

Yes, Roly, the whole subject came up because I indeed "give a rat's ass." I was teaching 5th graders a "leave no trace" outdoor ethics course and was emphasizing how long different items could trash up the environment if left. I quoted what I'd heard, that an aluminum can could last up to 180 years on the ocean floor, and I was later challenged by an adult who believed that couldn't possibly be true. Thus I asked this forum as well as other sources for confirmation. Answers have been varied and extremely interesting!

sjo hest,

Welcome aboard. Congratulations on teaching kids the "leave no trace" ethic. Ultimately, it doesn't matter how long trash lasts, dumping trash in any body of water sucks. The world needs more folks like you.

[Poida]

Charmc

When I die, I want my ashes scattered in the ocean.

How long do reckon I'll last?

Poida

[jehardiman]

Poida makes a good point. Everthing on land is going to end up in the ocean anyway. You, me, all the trash, all the heavy metals, all the radioisotopes spewed up from the core. Everything will be weathered away in time and end up in the water.

It's just a matter of scale and time. All that plastic floating out there now is 300 million years away from being oil again. It came from the ocean and will go back to the ocean.

In every breath we take, we breath some of the same oxygen and nitrogen breathed by the Pharaohs and Ceasars, and some of the elements that made up their bodies. The environment changes...seabeds are upthrust...alpine lakes become meadows...and all the species that inhabit that lake DIE!...and new ones are formed to take their place in the meadow. There is nothing more unnatural to me than the pseudo-intellectual agrument of some "environmentalists" that nature is static and man should not be changing it.

BTW, get a CNC handbook and look to see what is in "normal" seawater. In the shipyard we have trouble making something as corrosive as seawater to do tests with.

[hiracer]

Originally Posted by jehardiman

There is nothing more unnatural to me than the pseudo-intellectual agrument of some "environmentalists" that nature is static and man should not be changing it.

I agree. I don't see why we can't put untreated sewage in the ocean, nuclear waste, AND aluminum cans. Gonna get there some day anyhow. Why wait? Besides, nature is change.

* * *

"A straw man argument is an informal fallacy based on misrepresentation of an opponent's position. To "set up a straw man" or "set up a straw man argument" is to create a position that is easy to refute, then attribute that position to the opponent. A straw man argument can be a successful rhetorical technique (that is, it may succeed in persuading people) but it is in fact a misleading fallacy, because the opponent's actual argument has not been refuted."

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

[charmc]

Originally Posted by Poida

Charmc
When I die, I want my ashes scattered in the ocean. How long do reckon I'll last? Poida

According to both science and religion, you'd be gone before the ashes were made, mate!

If you go before me, let me know; I'll drink a beer and dedicate it to you.

[charmc]

Originally Posted by jehardiman

Poida makes a good point. Everthing on land is going to end up in the ocean anyway. You, me, all the trash, all the heavy metals, all the radioisotopes spewed up from the core. Everything will be weathered away in time and end up in the water.
It's just a matter of scale and time.

True, everything existing now will one day change and go back into the earth or the sea. And true, it's just a matter of scale and time. But, as my Mom used to say, "The devil is in the details." In nature, when an animal population increases and its waste products, consumption habits, etc. begin to change an area drastically, other forces act to restore balance. The herd moves on to find enough food, lack of food makes the herd weak and easy prey, weakened animals spread and succumb to disease, etc. Man is able to intervene to resist the normal consequences, either in beneficial ways (waste treatment, enhanced food production) or in harmful ways (manufacturing plants dumping vast quantities of waste products with higher concentrations of toxins). Typically, natural forces involve relatively small quantities and vast time periods. Man made processes do the opposite, introducing larger quantities of waste in short time periods. Sure, volcanic eruptions are natural, yet act like manmade processes, introducing large amounts of toxins in a short time. There was a time when volcanic eruptions were common. We weren't around then. Good thing, cause we wouldn't last long.

Originally Posted by jehardiman

There is nothing more unnatural to me than the pseudo-intellectual agrument of some "environmentalists" that nature is static and man should not be changing it.

I agree with you there. However, don't let distain for the knee jerk tree-hugging extremists hide the fact that dumping man made waste in the quantities we too often do in the modern world is not a natural force.

Originally Posted by jehardiman

BTW, get a CNC handbook and look to see what is in "normal" seawater. In the shipyard we have trouble making something as corrosive as seawater to do tests with.

Dealing with fresh, brackish, and seawater chemistry is a major part of what I do for a living. Chlorides are the principle corrosive compounds in seawater. If you want to run your tests a bit faster, try heating the seawater to 90-120 deg F; it will accelerate the corrosion rapidly, especially on austenitic stainless steels, even 316 and 316L. If you are designing a vessel intended to spend any significant time in the tropics, I would recommend replacing any 316 stainless pipe, tubing, or fittings with plastic. If it must be metal, use a duplex or one of the "super duplex" alloys.

Again, you're right in your points, but none of that justifies dumping waste.

[SamSam]

Originally Posted by charmc

I agree with you there. However, don't let distain for the knee jerk tree-hugging extremists hide the fact that dumping man made waste in the quantities we too often do in the modern world is not a natural force.

Given that we do dump massive amounts of man made waste into the environment, since a lot of these are man made chemicals and materials that are not found in nature, how does that stuff assimilate with the natural world? What sort of problems might be created when two things unknown to nature meet and meld together in and with natural things and possibly form something unknown to nature or man?
I guess you end up with movies like "The Creature From The Black Lagoon".

[charmc]

That's the point, Sam.

Don't forget "Swamp Thing".