My experience in the Severn is that water clarity, on average, was at its lowest point from about '83 to the early 90s. Since then it's improved somewhat on average, but is highly variable. Even going back to, say, the 1500s, the Bay and especially the tribs were almost certainly nowhere near as clear as the Bahamas. What makes the Bay and other estuaries such rich ecosystems also clouds the water to at least some degree.
Another fun fact is that there's never been a Chesapeake without people on its shores. Those people could be hard on their environment from the very beginning, including causing stream erosion and sedimentation, slash and burn forest clearing, etc. The large tracts of unbroken forests European settlers found in the eastern U.S. were largely due to reforested land after major native population declines, coupled with the decimation of most large, grazing animals by natives. This is not to denigrate natives or suggest that they deserved what European settlers did to them; it's simply to acknowledge that they were people and societies, just like us, with all of our positives and flaws. People have been woven into the Bay's ecosystem from the beginning.
Fast forward to the mid-1800s through the early 1900s, and much of what is forest today was cleared farmland. Look at any arial photo of the Bay watershed from, say, the 1910s through the 50s, and you'll see cleared land as far as the eye can see. The Severn River was closed to commercial oystering in 1912 due to pollution.
The difference today is that there's a lot more of us. And even though we have more forest cover than the early 1900s, we've also added a lot more impervious surface to what was once pervious farmland. In fact, even as population growth in the watershed has slowed significantly, we continue to add impervious surface at record rates. Some things are improving; agriculture has improved substantially, as has sewage. Air pollution has also improved dramatically. Suburban runoff is, unfortunately, the one category of pollution that continues to increase. But, you know, who wants to pay a "rain tax" when we can continue to pollute at will and blame everyone else for the Bay's decline? Or who wants to slow the spread of impervious surface when we can elect politicians who support sprawl development at any cost?
From what I've seen, the solutions are straightforward:
1. A Marshall Plan for oyster restoration. Scaling restoration 20-fold is still cheaper than just about any other solution and probably more effective.
2. Continue to pass tougher forest and meadow conservation laws. And continue to remove red tap from redevelopment. We have thousands of already cleared, paved land in the watershed that is economically defunct and begging for redevelopment.
www.trcp.org
