I also witnessed this at Deer Lake when I was there about 10 days ago. It was a man and what appeared to be his son. There were people telling them to stop but of course, they did not listen. I agree with Miss Kitty about tourists needing some sort of permits or beach training. Seriously, why can't people just enjoy nature without feeling the need to somehow alter it?
Wow, great photos! I don't know if this is 'bad' for the ecosystem-it looks like those kids did the work the next decent storm would have done.