What an enviable life you lead, and how wonderful that you're able to find just the right words to share your stories.
I'm keenly interested in ecological conservation. From the outside looking in, one would think Japan is doing a good job with the environment (everything being so clean). But upon inspection, of course, we see the problems you point to: sedimentation covering the sea floor, over-zealous breakwater projects, and the near complete loss of those rich saltwater tidal flats that healthy ecosystems need. Without awareness, our solutions are trading one set of problems with another.
Sigh.
Bashō's iconic imagery of the crane, which appears in so many of his haiku, could never be penned in the 21st century.