While clean water is a serious concern I think that ocean acidification and the possibility of it radically altering the biological make-up of the ocean presents us with an even greater problem.
You may not have to give up on sushi, you just might have to acquire a taste for jellyfish.
Myself and a friend looked in to doing this for sprinkler timers. The aim was to simplify the interface to a large degree and allow for configuration via a browser or mobile device.
As it turns out there is a patent on sprinkler timers with embedded web servers. The owner of the patent has posted hostile messages threatening legal action on any public facing website that posts about the handful of consumer products that might infringe on their patent.