Chesapeake Bay Barometer

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A recent Chesapeake Bay Program analysis of Chesapeake Bay health reveals an ecosystem in recovery. The study, known as Bay Barometer, offers a science-based snapshot of environmental health and restoration in a watershed that faces daily challenges from development and pollution.

While communities across the watershed have continued to take important steps to reduce the nutrient and sediment pollution that has long plagued the Chesapeake, the Bay remains impaired.

Nevertheless, some living resources are showing signs of resilience. Despite a sizeable drop in the abundance of blue crabs, underwater grass acreage has risen 24 percent, American shad have continued to return to Potomac River spawning grounds and the relative abundance of young striped bass in both Maryland and Virginia waters has recovered from the low numbers seen in 2012.

Bay Barometer Highlights:

Between 2012 and 2013, the abundance of underwater grasses in the Bay rose 24 percent. Scientists observed 59,927 acres of underwater grasses in the Bay and attribute the increase to an expansion in widgeon grass and a modest recovery of eelgrass.

In 2013, the abundance of American shad in the watershed increased to 41 percent of the goal. The Bay-wide trend was driven by rising shad abundance in the Potomac and York rivers.

Between 2013 and 2014, the relative abundance of juvenile striped bass in the Bay increased. Index values in Maryland and Virginia are about equal to historic values for each state, and are a significant increase from the low numbers seen in the region in 2012.

Between 2011 and 2013, 29 percent of the water quality standards for dissolved oxygen, water clarity or underwater grasses and chlorophyll a for the Bay and its tidal tributaries were attained. These results are not significantly different from those of the previous three-year assessment period.

Between 2013 and 2014, the abundance of spawning-age female blue crabs in the Bay fell 53 percent, from 147 million to 68.5 million. This number is below the 215 million target and the 70 million threshold, which means adult female crabs are in a depleted state.

Between 2009 and 2013, modeling estimates show that partners have reduced 20.28 million pounds of nitrogen, 2.04 million pounds of phosphorous and 497 million pounds of sediment. This means that nitrogen loads to the Bay fell 7 percent, phosphorous loads fell 11 percent and sediment loads fell 6 percent.

Since 1989, 2,576 miles of fish passage have been restored to rivers and streams.

Since 1996, 7,994 miles of trees and shrubs have been planted along rivers and streams.

Between 2010 and 2013, 6,098 acres of wetlands were established, rehabilitated or reestablished on agricultural lands.

8,371,682 acres of land have been permanently protected from development.

1,208 public access sites have been established across the watershed.

The data in Bay Barometer reflect the Chesapeake Bay’s health over the course of many years and, in some cases, decades. The publication offers a snapshot of the best available information from 2013 and 2014 on ecological health and our efforts to protect and restore the nation’s largest estuary.

source: Chesapeake Bay Program

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