The three ETI tools. Tool 1 assesses susceptibility of estuaries to eutrophication, Tool 2 provides information on monitoring indicators and a method for combining indicators to score current estuary trophic condition (banded from minimal (A) to very high eutrophication (D)), and Tool 3 provides a Bayesian Belief Network of estuaries to predict trophic scores when indicator information is lacking or when users wish to test scenarios of changed nutrient loads. Estuary type is considered within several of the tools’ functions.