Au contraire, mon ami. Aluminum corrodes away to nothing in a very short time in salt water. Litter doesn't ruin anything but aesthetics in most cases. Plastic bags and other debris, etc, can be a hazard to marine life and very occasionally land animals. For the most part, it's harmless, just very ugly. As peoples standard of living increases, the availability of junk goes up with it. Unfortunately, the social changes to deal with the trash doesn't occur at the same rate.

Over use of pesticides and fertilizer are not readily apparent but way more damaging to the environment. Think about that the next time you spread those chemicals on your lawn.