Do we need to address waste at the source? Sources are diffuse, innumerable, and spread among different jurisdictions with different levels of commitment to environmental stewardship. I'm skeptical of our ability to stem pollutants at the source.

There's a certain attraction to centralized cleanup efforts substituting for this near-impossible task of enforcing source standards worldwide. While it's theoretically less efficient to pollute and then clean it up, this model may have the advantage of actually working.

It really depends on the cost benefit analysis. If we can convince the largest polluters to reduce their pollution levels to bellow what can be removed via beach cleanups (which are relatively low effort), eventually that gets a clean enough ocean.

Framing the issue is important. Yes, the environment is all good, but what the polluting nations will gain from reducing their pollution needs to be highlighted. Less plastic in rivers probably requires less plastic on streets which probably requires better sanitary conditions in general which means healthier workers and higher productivity. Cleaner air means less breathing problems means healthier workers and higher productivity, etc. Eventually, people might notice the nicer environment and develop that as a cultural goal in itself, as the US eventually did after getting tired of rivers catching on fire, but emphasizing worker productivity is probably a quicker way to get developing countries on board. Something about healthy oceans = more protein from the sea should help a bit too.

The plastics are diffused, innumerable, and spread through-out the ecosystem in varying environmental conditions where solutions will have varying effectiveness and possible negative impacts on wildlife. I'm skeptical of our ability to implement a large-scale collection effort that will collect a meaningful percentage of the waste, with a further concern that a poorly implemented solution may in fact add to the waste and/or impact the environment in ways just as damaging as the pollutants it does remove.

Yes, enforcing standards worldwide is a "near-impossible" task. But cleaning up waste at the scales we're talking about, after it's entered the ecosystem, is impossible. There is no magic bullet here, and the more people who ignore what has to be done to fix the problem, hoping projects like this will make it better, the worse it will get.

> cleaning up waste at the scales we're talking about, after it's entered the ecosystem, is impossible.

That's a very strong claim, especially attached to an article about cleanup mechanisms. Are you sure some kind of synthetic biology mechanism couldn't work?

Waste removal (be it carbon or plastic) is an engineering problem; source regulation is a political problem, and political problems tend to remain unsolved until it is impossible that they remain unsolved.

Yes it was a strong claim, and I should clarify that I specifically meant impossible using a solution based on ultra-large-scale-infrastructure methods like this. The scales required to have a meaningful impact on the quantities of plastic in the ocean are such that the project itself would have a larger negative impact then the waste itself, and this specific solution seems to have some serious questions about how effective it will be at removing any amount of waste, given dispersion depths and scale of the plastic particles.

A synthetic biology mechanism could be a viable approach at these scales, and there are some very interesting developments in this area in regards to breaking down and conversion of waste materials. There is a whole host of potential problems, largely of the "impossible to predict and impossible reverse" kind, that come with the idea of introducing a synthetic orgasm into the global ecosystem.

Yes, waste removal is an engineering problem, but one that may not have a safe and viable solution. Source regulation is a political problem, with all complexities that come with it, but it's a workable solution, and also has the additional advantage of at least helping even if only partially implemented.

> Waste removal (be it carbon or plastic) is an engineering problem; source regulation is a political problem, and political problems tend to remain unsolved until it is impossible that they remain unsolved.

Then move the plastic collection to the mouth of the 10 rivers in south east asia where the plastic is being emitted from.

I would enthusiastically support research and testing on this solution.

Many of the objections to clean-up in the open-ocean are not relevant here. The depths are very restricted, the ecosystems are more limited, the weather conditions less extreme and less variable, the plastics should be less broken down. The impacts and infrastructure would be similar to, and on the scale of, projects such as locks and dams.

I would see this as a first step to source control. Looking at collected materials, it would become quickly obvious where the major sources of the plastics are, and they could start being addressed.

There is a social issue here too though. I would expect this kind of project would be resisted in the same way that more local clean-up and source-control efforts in those regions are already resisted.

Edit: There is also the issue that a sizable portion of the ocean plastics seem to be from discarded/lost fishing equipment.

> I would enthusiastically support research and testing on this solution.

This would probably be helpful to deploy at scale: http://baltimorewaterfront.com/healthy-harbor/water-wheel/

Alone it's not an entire solution, but the technical challenges are not terribly difficult if you can constrain by the rivers dumping waste into the ocean. This is more a funding/political/logistical issue (as others have mentioned/insinuated in-thread).

That would be a good start.