State of the Inland Bays 2016
The 2016 State of the Delaware Inland Bays report is a compilation of environmental data about the Bays that is updated every five years. The content is grouped by subject matter into 35 bite-size indicators that can provide communities, decision makers, and concerned citizens with robust scientific information to help restore and protect the Inland Bays and the surrounding watershed.
The population in the watershed more than doubled between 1990 and 2010 when the last census was conducted. Population growth is driving many of the changes that are impacting the Inland Bays. After a slowdown brought about by the recession that began in 2008, intense development is underway again, much of it near waterways where water quality impacts can be the greatest. With development comes impervious surfaces. Parking lots, roadways and roofs now cover over 10% of the watershed’s land area—a point at which studies show detrimental impacts to water quality in estuaries.
Nutrient pollution from nitrogen and phosphorus remains the greatest threat to water quality in the Bays, but actions taken to reduce nutrient inputs give reason for optimism. The volume of tidal water passing through the inlet has increased over time. This helps flush out nutrients, but has also contributed to degradation of marshes in the Bays. Overall, water quality in the Inland Bays remains fair to poor, though Little Assawoman Bay and open waters near the inlet are showing some improvements.
More than 6,800 homes on septic systems were connected to central sewer since 2011, and discharges from point sources are down more than 80% since the 1990s with only two ‘point sources’ of pollution to the Bays remaining out of thirteen. Voluntary actions to reduce nutrient pollution, prescribed by the Pollution Control Strategy for agriculture and stormwater, show little progress, highlighting the need for dedicated funding.
Human health risks continue for those using the Bays for recreation. Most tributaries and canals continue to have very poor water quality and are unsafe for swimming or for the harvest of shell fish.
As the watershed urbanizes, loss of wetlands and natural shorelines impact both migrating and resident animal populations. Blue Crab populations remain low, and recreational fishing and its local economic benefits have not yet rebounded from losses brought about by the recession. Bald Eagles and Ospreys are thriving in the Inland Bays, and hard clam populations have been stable since the 1970s. Bay grasses, a signature species of healthy coastal bays, are still largely absent from the Inland Bays due to nutrient pollution.
Global emissions of carbon dioxide are bringing higher air temperatures, a longer growing season, and warmer Bays. Sea level in Delaware is now rising at a rate of 1.1 feet per century and is projected to increase to nearly five feet by 2100.
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