The federal government established the Blackwater refuge in 1933 to serve as a stopover point for migrating blue-winged teals, ospreys, black ducks and Canada geese.A great deal of the problem with the Eastern Shore marshes was due to the Nutria, the invasive South American rodent, which was far more destructive than any of the native species. The Nutria have either been eliminated, or all but eliminated by a recent campaign to exterminate them. Other problems are fires, mostly set by humans to "clear" the marsh, which prevents the build up of the peat. Not to mention, occasionally paving it over, ant then being surprised that it floods with increasing frequency.
It has become an important Eastern Shore resource, drawing more than 180,000 tourists each year. Its marshes protect communities from flooding and erosion, and they provide vital habitat for young broods of commercially valuable fish such as menhaden and flounder.
But since 1938, the 29,000-acre preserve has lost about 5,000 acres of marshland, according to an analysis of satellite data by a team at Salisbury University in 2009.
The changes started with Swiss cheese-like gaps in the marsh, as floods gradually overwhelmed the flowering bulrush, cordgrass (more commonly known as salt marsh hay) and other grasses.
Those grass varieties evolved to handle the monthly high tides that come with every full moon, but they can’t survive for long if their roots are waterlogged. The flooding stunts the growth of their roots and limits the buildup of peat — soil-like gunk made of decaying plants — that forms the marsh floor.
Curson said the changes are obvious even before marshland gives way to open water. On annual bird-counting surveys, he has grown used to taking a step through marsh grass only to suddenly find himself waist-deep in mud.
During the 2015 count, he said, it happened something like five times more often than in the past.
“I could feel that the root mats had disintegrated that much more,” he said.
As waters rise — as a result of climate change, and also because the Eastern Shore has been slowly sinking since the last ice age ended 10,000 years ago — new marsh areas are developing where forests once stood.
They are marked by isolated dead tree trunks known as snags, which can be dangerous for small marsh creatures, because they serve as perches for bald and golden eagles.
The rising water has added about 3,000 acres of wetlands to offset the losses, but conservationists say the new marshes aren’t the same. They’re often invaded by Phragmites, upland tall grasses with less extensive root systems than native plants.
Phragmites can’t support the same diverse ecosystem as native species because they don’t have the flowers, seeds and roots that support marsh birds, fish and rodents.
The changes are blamed for drastic declines in the populations of birds such as the saltmarsh sparrow and black rail.
Again, I'll show the data from NOAA:
Sea level has be rising in Chesapeake Bay since the end of the last ice age, and there's no evidence whatever that sea level rise is accelerating due to "global warming":
Do not ever think that AP, the WaPo, NYT etc will ever show this data.