Nereis Park assocoation (http://nereispark.org/) has produced an educative poster presenting the bioturbation process and functional groups than can be used for both the scientistic and general audiences. The poster is so far available for free in 15 languages (http://www.nereispark.org/divers/NPretsop/posters.php3). I propose you to have a look on it and feel free to use it for your scientific and educative activities. Do not hesitate to spread the information to others colleagues, teachers, associations.