December 20, 2012 Evaluating Protocols to Quantify the Significance of Aquatic Ecosystems at Regional and National Scales: Proceedings of a Workshop, Cambridge, MA, 20-22 July 2011 EMRRP-EBA-18: Evaluating Protocols to Quantify the Significance of Aquatic Ecosystems at Regional and National Scales: Proceedings of a Workshop, Cambridge, MA, 20-22 July 2011