Maps

Sufficient dissolved oxygen (DO) is crucial for the fauna of the Chesapeake Bay to exist. Different aquatic organisms have different DO requirements. Many finfish need at least 5 mg/l while some bottom dwelling worms and clams need as little as 1 or 2 mg/l to survive. The different designated use zones (Open Water, Deep Water and Deep Channel) reflect the different needs of the species that inhabit different parts of the water column. Note: Some areas of the DO Designated Use were changed in 2007 from the original published map of 2003.

The map shows the average Index of Biological Integrity Score for phytoplankton by monitoring station for 2007.

The Phytoplankton (Index of Biological Integrity) (2007) map show the Percent of the goal achieved by CBP Monitoring Segment.

The 2007 Chlorophyll a Goal, Percent Achievement by Segment

This map shows the Percent of the Index of Biological Integrity Indicator Goal achieved by segment.

This map shows the 2007 Indicator Status of the Benthic Index of Biological Integrity by station.

This map shows the percent passing of the Water Clarity goals for each Chesapeake Bay Segment in 2007.

Each state in the watershed conducts benthic macroinvertebrate assessments as part of its biennial water quality assessment report mandated by the Clean Water Act. Where assessed benthic macroinvertebrate communities are deemed the most degraded, states must designate those stream segments as impaired and add them to the list of impaired waters in need of cleanup. The Bay Program state partners - Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia - used the data and results from their 2006 water quality assessments to prepare summaries of stream conditions in each state. The methodologies for benthic macroinvertebrate assessment vary by state, therefore a synthesis of results across the entire watershed was not attempted at this time The map presents a summary of each state's assessment results within the boundaries of the Chesapeake Bay watershed.

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

Over the past decade, sightings of the zebra mussel, have increased in the Chesapeake Bay watershed. Zebra mussels can out-compete native species for space, food and nutrients. They also clog water intakes and damage equipment by attaching to boat motors and hard surfaces. Zebra mussels spread by attaching to watercraft, aquatic plants, nets, fishing equipment, or through water currents as larvae. For this reason, public awareness, education and warning are crucial elements in the fight against zebra mussel invasion. This map lists zebra mussel sightings in the Chesapeake Bay Watershed through 2010.