The Internet provides a unique opportunity for scientists to be in direct contact with the public in order to promote citizens' scientific literacy. Recently, Internet users have started to spend most of their online time on social networking sites (SNS). Knowledge of how these SNSs work as an arena for interaction, as well as for the development of scientific literacy, is important to guide scientists' activities online, and to be able to understand how people develop knowledge of science. This was evaluated by scrutinizing the Facebook page of the Monterey Bay Aquarium Research Institute and the consequences for users' ocean literacy. We investigated which practices could increase the number of users reached by a Facebook story. We also found that Facebook pages do not offer the appropriate social context to foster participation since it has only a few of the features of an arena where such practices could develop. We study the use of a Facebook page for developing science literacy.Posting videos and photos help to reach a wider audience than text and links.The frequency of posting is important to reach more users.Facebook pages do not offer appropriate social context for learning.Shared stories offer a more supportive foundation for participation and learning.