Maps

Tidal waters that are impaired for part or all of the indicated Bay segment by toxic chemicals based on each state's implementation of the Clean Water Act.

This map demonstrates the attainment status of those Chesapeake Bay Program monitoring segments that have numeric chlorophyll a standards for the Open Water designated use during the 2009-2011 assessment period.

This map demonstrates the attainment status of those Chesapeake Bay Program monitoring segments that have dissolved oxygen standards for the Migratory, Spawning and Nursery Habitat designated use during the 2009-2011 assessment period.

This map demonstrates the attainment status of those Chesapeake Bay Program monitoring segments that have dissolved oxygen standards for the Open Water, Deep Water, and Deep Channel designated use during the 2009-2011 assessment period.

This map demonstrates the attainment status of those Chesapeake Bay Program monitoring segments that have SAV and/or water clarity standards for the Shallow Water Bay Grasses designated use during the 2009-2011 assessment period.

The 2012 Dissolved Oxygen Indicator showing Percent of Goal Achieved using the three year analysis method.

An effective way to measure the health of freshwater streams and rivers is to study the many tiny critters that live in these waters, called “benthic macro-invertebrates.” The abundance and diversity of snails, mussels, insects and other bottom-dwelling organisms are good indicators of the health of streams because they can’t move very far and they respond to pollution and environmental stresses. Benthic macroinvertebrates are generally harmed by direct and indirect effects of pollutants such as metals, acidity, sediment, pesticides, nitrogen and phosphorus. These pollutants come from sources such as mining, agriculture, urban and suburban runoff, automobile and power plant exhaust, and wastewater treatment facilities. Health of streams was evaluated by the Chesapeake Bay Basin-wide Benthic Index of Biotic Integrity (or “Chessie B-IBI”), which was developed from benthic macroinvertebrate data collected across the entire Chesapeake Bay watershed from over 20 federal, state, local, and river basin commission monitoring programs throughout the Chesapeake Bay basin. Each sampling event is scored on a standardized quantitative scale that allows scoring across jurisdictional boundaries. B-IBI scores were averaged for each site over all years of sampling (2000-2010) and then qualitatively categorized in one of the following categories – very poor, poor, fair, good or excellent for a total of 15,112 scored sites. An analysis was conducted on a subset of the 15,112 sites to investigate regional variation in the B-IBI scores. The subset of sites (8,871) were chosen where a random sampling design was used. By using only randomly selected sites, BIBI scores can be averaged across the smallest feasible watershed size without introducing bias associated with sampling designs that target areas with known degraded or high quality waters. For more information see: Buchanan, C., K. Foreman, J. Johnson, and A. Griggs. 2011. Development of a Basin-wide Benthic Index of Biotic Integrity for Non-Tidal Streams and Wadeable Rivers in the Chesapeake Bay Watershed: Final Report to the Chesapeake Bay Program Non- Tidal Water Quality Workgroup. ICPRB Report 11-1. Report prepared for the US Environmental Protection Agency, Chesapeake Bay Program.

Existing public access sites in the Chesapeake Bay watershed as reported by state partners through 2012. Sites added in 2012 are depicted in orange, while sites existing before 2011 are blue.

The Phytoplankton (Index of Biological Integrity) map shows the percent of the goal achieved by CBP Monitoring Segment.

The map shows the average Index of Biological Integrity Score for phytoplankton by monitoring station.