Listen to part of a lecture on the topic you just read about. The ocean cleanup array is an interesting idea, but it does have some problems. First, let's talk about the cost of these devices. You know, people underestimate how hostile the ocean environment is. Ocean water has corrosive chemical properties and ocean waves exert strong mechanical forces. Devices placed in the ocean get easily damaged and need to be repaired very frequently. The repair expenses can be large. Also, the total amount of plastic that enters the ocean every year is really huge. It's so huge that we would need 500 of these devices to keep the oceans clean. So the cost of 400 million dollars per device is just a start. You need to add to that number, all the repair expenses that I mentioned, and then multiply that figure by 500, because that's how many devices we would need. It should be clear that overall this is not a cheap solution. Second, the effects of life, yes, swimming animals can avoid the device, but consider plankton. Plankton consists of tiny microscopic creatures. They aren't strong enough swimmers. So they're carried by ocean currents. So the ocean currents that draw the plastic to the barriers will draw in large amounts of plankton as well. When the plastic is removed from the devices, the plankton will be removed with it. Removing large amounts of plankton from the oceans would negatively affect the entire ocean food chain, because plankton is an important food source for many sea animals. Third, recycling. The problem is that plastic collected from the ocean is not quite ready for recycling. For example, polyethylene and polypropylene objects break down into small pieces in the ocean. When the pieces are collected, they're all mixed up. So recycling facilities first have to separate them. That costs money. In addition, sea organisms get attached to those pieces of plastic and have to be cleaned off. That also costs money. If recycling facilities have to invest too much effort and money into making this plastic ready for the actual recycling, they will not be interested in buying ocean plastics.