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> Plastics that can metabolize in oceans are highly sought for a sustainable future.

Really? I think that putting more nutrients in the water is almost as bad as having plastics floating around. The Baltic sea for example, have dead zones caused by agricultural runoff.

Surely, the best would be to not put more stuff in the water?

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Plastics are mostly carbon and hydrogen atoms, neither of which are even remotely limiting factors because autotrophs at the bottom of the food chain produce plenty of both from water and carbon dioxide.

Agricultural runoff is mostly nitrogen and phosphorus, which are limiting factors (hence why we have to supplement them in agriculture).

> Plastics are mostly carbon and hydrogen atoms

In general, this particular stuff is significantly different.

The article mentions sodium hexametaphosphate [0] and guanidinium sulfate [1], which have phosphorous and nitrogen respectively. Those are both common in fertilizers and are implicated in algal blooms.

[0] https://pubchem.ncbi.nlm.nih.gov/compound/Hexasodium-hexamet...

[1] https://pubchem.ncbi.nlm.nih.gov/compound/Guanidinium-sulpha...

it is certainly good to not put more stuff in the water. i would suggest it is even better not to make stuff that shouldn't go in the water. but apparently a lot has already been made and there's constantly more of it in the water, and it looks like nobody is stopping

so if some major fraction of present production of that shit that shouldn't go in the water can be eliminated, and satisfied by an alternative that is not a persistent accumulating poison, i'll take it

Seems like a pretty easy problem to solve if you ask me:

https://www.scientificamerican.com/article/stemming-the-plas...

Someone should send this link to Trump and Elon Musk so America and the EU can slap some actual serious and economy-breaking tariffs on those countries. I know that sounds snarky and drastic and funny and off-topic, but we seriously need actual serious politicians that just get shit done. We've tried the "reasonable politicians" approach so far, maybe it's time to bring in people that are unpalatable but actually willing to break shit and blockade some actual evil people and countries around the world in order to make positive change.

There seems to be a high correlation with people who are enthusiastic about breaking things to enable "simple" solutions, being legislative blockaders (instead of negotiators) of forming good policy from/with others, and not caring about external costs to the point of making that a vocal policy point.

A lot of damage is done in the name of real problems, associated with high frustration, leveraged politically.

If you mean this particular thing because it involves compounds [0][1] with nitrogen and phosphorous, then I agree it's a valid concern to look at.

However for existing plastics in general--mostly carbon, hydrogen, and oxygen--it's less of an issue. Just because a material can be metabolized doesn't necessarily mean it's a rich source of energy, or that the chemicals in it will unlock some limiting-factor that was holding back a population-boom.

Just to prove it's possible, consider lignin, another C/H/O polymer and the core component of wood. It was ecologically un-digestible for a long time until something (fungi) evolved to dismantle it efficiently. Yet even now, its breakdown is a slow, low-margin process that occurs in the background.

____

Side note: The long delay between the evolution of trees and the evolution of something to eat wood has been suggested as a cause of coal formation, but it is disputed. [2]

[0] https://pubchem.ncbi.nlm.nih.gov/compound/Hexasodium-hexamet...

[1] https://pubchem.ncbi.nlm.nih.gov/compound/Guanidinium-sulpha...

[2] https://www.pnas.org/doi/10.1073/pnas.1517943113

The natural input of "nutrients" to the ocean is vast, compared to the natural input of modern artificial plastics.

Depends on what you put in, how much, and where.

I do not think moderate quantities of nutrients are a problem, and very likely has benefits.

What the other commenter is alluding to is that, if this comes into widespread use, it won't just be a moderate amount. We produce mind-boggling amounts of plastic waste and a lot of it would concentrate in rivers and estuaries.

It will be a moderate amount compared to the amounts that produce dead zones.

These would not break down into the kinds of nutrients that cause algal blooms and dead zones. That is cause by nitrogen and phosphorus runoff.

That's interesting. I didn't have access to the paper, just the abstract, so didn't know it was different.

Well yeah but good luck with that.

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