August 1999 Maryland status and trends information is calculated from data collected as part of the DNR's Chesapeake Bay Water and Habitat Quality Monitoring Program. Trends are a measure of how the system has been changing over time, either improving or worsening.
Total phosphorus is measured directly.
Abundance of algae is estimated by measuring active chlorophyll a . Active chlorophyll a from surface samples only is used in this analysis. No chlorophyll measurements are taken in non-tidal areas. Summer bottom dissolved oxygen is measured directly. The dissolved oxygen data used in this analysis are from samples take during the months of June to September in bottom samples only.