Greenwire: U.S. EPA is weighing a revision of standards aimed at preventing the acidification of marine waters. The effort marks the first time EPA has invoked the Clean Water Act to address ocean acidification, and comes in response to a 2007 petition from the Center for Biological Diversity. The center noted that EPA has failed to update the pH standard since 1976 and has ignored research published since then. Concerns about ocean acidification have risen lately, as research shows a …