A very simple and handy way to do something for the environment, especially the sea, is to use an online guide for buying fish. The International Seafood Guide can be found at http://fischimhandy.de/ formatted in a way suitable for mobile phones. So the information what fish to buy is always at your fingertip.

It works quite easy. Go to the web site, choose your language, and it shows you different names of fish. Choose the one you want to buy and it says whether it is environmentally a good or bad idea to do that.