Acidification and Disintegration, Part II

Yesterday, I set up the issue: the ocean is increasingly acidic, thanks to ever more CO2 in the atmosphere. It's already affecting creatures as far away as Antarctica, and is decimating the wild oyster in the northwest U.S.

Learning this, and how natural carbonic acid in rain dissolves beached shells, I decided to do an experiment of my own. Just what does an acid really do to a shell, and how long does it take? Plus, with all the plastic waste swirling in the ocean, how might ocean acidification affect plastics?

So off to work I went. First, the ingredients:

Distilled white vinegar, 2 Atlantic surf clams, 1 blue mussel,
1 #4 plastic, 1 #5 plastic, 1 #6 plastic, and unk plastic bucket

As mentioned before, the pH scale measures acidity/alkalinity, 0 being most acid, 14 being most alkaline, 7 being neutral. Pure water should have a pH of 7. By mixing with CO2 in the air, rainwater tends to have a pH of about 5.6. What's the pH of distilled white vinegar? Anywhere from 2.0 - 3.4. The best way to tell? Test it yourself:

The litmus test

Seems suppliers might be a little bit cheap with the vinegar these days - the paper looks more like 4.0 than 3.4. Still, 3.4 is very mild -- about as acidic as an apple. (Lemon juice is 2.3, a can of Coke is 2.5.) Certainly nothing dangerous to a person. But what about a shellfish? Let's see. Here's the moment I first put all the ingredients into the bucket:

Instant reaction

Like Alka-Seltzer in a glass of water, the shells immediately started reacting with the vinegar.

A quick word about seashells. As, say, a clam is growing, it develops a thin "skin" around its outside, called the periostracum. It's like a tiny membrane that wards off the outside world - including weak acids. But it's delicate, fragile, and usually worn away as the creatures lurch back and forth in tides, or burrow into the gritty sand on the seabed. In most cases, periostracum will not help a mature bivalve fend off an acid attack.

Back to the experiment. I poured enough vinegar into the bucket to cover the shells. Twice a day, I fished out the larger of the two surf clam shells and photographed it. Each morning I topped off the vinegar, and I replaced the vinegar twice through the length of the experiment. The pH of the solution ranged anywhere from ~3.4/4.0 to about 6.0 depending on how fresh the vinegar was. Here's what happened:

Start of experiment --
shell intact, periostracum worn in places

After 1 day -
periostracum darkened, bubbling

After 2 days

After 3 days

After 4 days

After 5 days

After 6 days

After 6 1/2 days

After 7 days

After 7 1/2 days

That's it. Gone. After just over a week, the Atlantic surf clam that had been half a foot long... is gone. In fact, all 3 of the shells I put in were gone. Leaving nothing behind but shreds of their empty skin. What do you think happened to all the various plastics? Long-time followers of the Flotsam Diaries will hardly be surprised by the answer:

Of course the oceans aren't predicted to drop to a pH of 3.4. Or even 6.0. They don't have to. The tiniest drop, from 8.1 to 7.8, causes a cascade of crises - some shellfish devote so much time to building & repairing their shells that they don't have the energy to devote to muscles, movement, immune systems, or procreation. A drop of just .2 killed half the copepods in a test group in a week. One chilling experiment showed that a drop of .4 killed 99.9% of a species of brittlestar larvae in 8 days.*

This isn't a small problem, or a made-up issue. This is reality, happening now. These are foods not only eaten by people, but are also the base foods for many of the other major foods we eat.

But who knows. Creatures have adapted before -- though it took them millennia, not decades. Perhaps they'll be able to get their energy from the plastics swirling in the water. Because, as we all know, plastic is forever.

Day 7 1/2 - The end

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* See this Scientific American article of August 2010 for these and many other examples.

The Plastic Ocean

In 2010, on almost any beach, at almost any time of the year, there is a constant: plastic. From the Jersey Shore to the distant paradise of Midway, plastic pollution has reached nearly all corners of the planet. We've done this all within a few generations. And the big question seems to be "Why is there so much plastic in the ocean?"

So I put together a little chart.

Recycling is wonderful. But it is not endless. Once a piece of plastic comes into the world, the only way it is known to end -- really end -- is in the fires of an incinerator. Until it meets that fate, it will persist. And given half a chance, it will enter a gulley, a roadside ditch, a culvert, a storm drain, a rill, a brook, a stream, a river, a floodplain. And eventually the ocean. Where it will remain plastic, even as it photodegrades to a microscopic soup.

So the question isn't "Why is there so much in the ocean?" It's "How did we not think this was going to happen?"

Collection Report August 18, 2010

A bit late getting this one up. But at long last!

August 18 greeted me with a few breaking clouds & a coolish breeze, the first reminder that our summer is winding down.

It's that time of year where there's a tension in the air -- an expectation. More people are on the road, trying to squeeze out the last bit of vacation. Folks are getting to the beach earlier, lingering longer. Minds are focused on anything but the return to school, layers, jackets. Which might explain how someone could forget this:

Cushy chair, cold drink, tasty snacks... *POOF* Just walked away. Confession: I did not put this into my bag & record it.

Second confession. I also didn't count everything I did pick up. I took a moment from bagging to dump several dozen jagged remnants of a Bacchanal into the metal trash bin on-site:

Always comforting what people will leave in the sand.

On to the finds. Zone N (which I really thought was going to be small):

It wasn't small. 266 finds:

• Building material: 3 (sawn blocks & part of a plank/clapboard)
• Foam/Styrofoam: 9 (inc. another part of the airplane that I started finding back on July 27)
• Fishing misc.: 2 (claw bands, one fresh & one a bit jagged)
• Food-related plastics: 37 (inc. 5 water/soda bottles plus 3 burned bits of bottle)
• Food-related metal/glass: 13 (inc. a piece of what was just starting to turn into worn-down seaglass)
• Non-food/unknown plastics: 32 (inc. 5 bandaids, balloon, shovel handle, action figure arm, packaging reading "Toys $2.99", orange plastic nozzle)
• Cigarette filters/plastics: 112 (101 fresh, 6 floaters, 5 packaging - including cigar pack with 7 wrapped cigars still inside)
• Paper/wood: 44 (inc. piece from Spanish-language magazine, fireworks packaging (still from July 4th??), business card, pail & shovel label, umbrella tag, bath towel tag)
• Misc./unique: 14 (inc. size XS ripped shorts, sock, 3 wads of gum, several tattered string/rope scraps)

Another colorful, if mostly predictable, collection. A few standouts:

Somebody's ultra-army is a tad sadder now

Four "Huh?"s

Foam from same original objects every week

Moving on to Zone S, which, as usual, was rather subdued:

54 finds:

• Building material: 0
• Foam/Styrofoam: 10
• Fishing misc.: 0
• Food-related plastics: 3 (inc. two burned things)
• Food-related metal/glass: 2
• Non-food/unknown plastics: 5 (inc. very aged/brittle little capsule holder?)
• Cigarette filters/plastics: 31 (27 fresh + 4 floaters)
• Paper/wood: 2
• Misc./unique: 1 (sea glass)

It's funny, sea glass always seems to be a Zone S thing. And as an example of what happens when plastic sits out too long:

Photodegradation, in all its glory!

Big takeaway from this week: People at the beach just can't seem to help burning stuff. And a second takeaway: You can toss that plastic bottle or wrapper into a roaring fire pit, but when the party's over and the embers die, it hasn't gone away.

I'll end this week with a teaser. If you're getting tired of the same old beach trash week to week, you're not alone. (People go to beach and litter, dog bites man.) But I was back there this morning. Yesterday (August 25) it rained all day, with some pretty serious winds too. Here's what I saw at 8:00AM:

A hint: It wasn't just kelp that washed up

Breaking It Down

"It doesn't go away." A phrase repeated a number of times already in the short life of this blog. Modern flotsam is a problem because so much of it is persistent -- it doesn't go away.

But everything rots, right? I mean, a plastic bag or flowerpot gets brittle and shreds if left out in the sun over a summer.

(photo courtesy flickr/wygd and licensed by Creative Commons)

So clearly, plastic does go away over time, right?

Wrong. With other trash, like, say, a napkin (which is just tree pulp) or nail or chicken bone, nature has had hundreds of millions -- in some cases billions -- of years of trial and error in figuring out how to recycle it.

Not so with plastics. The first artificial plastic was created in 1862, but plastic use only really exploded after World War II. For all intents and purposes, nature has only been exposed to plastics for a few generations.

And it has no idea what to do with them.

Plastics are synthetic polymers - long, large chains of (mostly) carbon and hydrogen molecules composed of repeating structures that are tightly bound together. The bonds that make them strong also make them incredibly resistant to microbes, weathering, rainwater, freeze/thaw, anything that can break a plastic back to its carbon and hydrogen. Science still knows of nothing that can be used in nature to break it up. (A high-schooler made big news in 2008 with a possibility, but there has been no effective follow-up since.) Estimates on how long plastic takes to break down in nature range from a century to thousands of years, for a simple reason: nobody knows.

Back to the shredded plastic bag. It's not biodegrading, it's photodegrading. Sunlight can make plastics brittle and break apart. But they're not breaking down -- they're just becoming smaller versions of themselves. Eventually they get small enough to swirl around the ocean as a "soup" of tiny colored fragments that can be ingested by plankton and then work their way up the food chain.

This picture, courtesy the Algalita Marine Research Foundation, shows the contents of a brief sample trawl in the North Pacific Gyre, a vortex in the ocean hundreds of miles from any island or shipping lane. That's all plastic, brought in by the currents.

Sometimes, plastic doesn't have to break down too small to have an effect.

This image, from CBC News, shows a dead albatross on Kure Atoll in the middle of the Pacific. This and other atolls around Midway are dotted with the carcasses of hundreds (thousands?) of albatross like this one. They ingest colorful plastic bits floating in the water, which (surprise!) don't break down in stomach acid. Eventually, the bird always feels full and stops eating altogether, ultimately dying of starvation.

Kure Atoll is 1200 miles from the nearest inhabited island.

When you see a piece of milk bottle floating in the harbor on a cruise, or see plastic wrappers on the beach at low tide that all get washed into the ocean at high tide, just remember: they don't go away.