The Chesapeake Bay report card compares 11 indicators (dissolved oxygen, nitrogen, phosphorus, chlorophyll a, water clarity, aquatic grasses, benthic community, stewardship, walkability, heat vulnerability index, fish community) to scientifically derived thresholds or goals. These indicators are combined into an Overall Health Index, which is presented as a subregion percent score. Other indicators (turbidity, water quality index, blue crab, bay anchovy, striped bass, protected lands, social index, median income, housing affordability, income inequality, jobs growth, environmental justice index) presented on these pages are not included in the score.