Natural objects such as fish and trees have frequently been used as symbols to accompany vague environmental claims such as "earth friendly." CAN/CSA-ISO 14021 prohibits that type of usage. There needs to be a clear connection between the products and the symbol.
Source: 1. Requirements for Self-Declared Environmental Claims, ISO 14021 2. Environmental claims: A guide for industry and advertisers. Canadian Standards Association and Competition Bureau of Canada, June 2008, p. 22.