Monday, December 9, 2013

Bay Barometer: Fair at Best

Adult female blue crabs are rebounding in the Chesapeake Bay, oysters show signs of resistance to deadly parasites, striped bass continue to hold their own, American shad are returning to spawn and nutrient pollution and sediment loads are dropping.

These are a few of the indicators in this year's "Bay Barometer" from the Chesapeake Bay Program that key elements of the bay and its vast watershed continue to recover, slowly but surely, from decades of pollution, disease and overfishing.

By every measure, however, the bay is still a troubled estuary and the report notes continuing areas of impairment. Among them:
• Nearly three-quarters of the tidal segments analyzed were partially or fully impaired by chemical contaminants.

• Less than half of the bay sites surveyed had healthy bottom habitats.

• Nearly 60 percent of non-tidal streams are in poor or very poor condition, caused chiefly by polluted runoff — although the report does note that about 70 percent of monitoring sites show improved levels of nitrogen and phosphorus in the long run, and 28 percent show improvements in sediment. More reductions are needed, but experts say there is usually a lag time between restoration efforts and the end result of water quality.

• Underwater grasses declined in the bay for the third year running.

"This report," said Beth McGee, "is a sobering reminder that although we have made progress in reducing pollution, we still have a long way to go to restore local rivers, streams and the Chesapeake Bay." McGee is senior water quality scientist with the Chesapeake Bay Foundation.
I find the various "Bay Barometers" and "Bay Report Cards" more about getting a little publicity for the cause (the Bay Program and Chesapeake Bay Foundation in the case) than about actually measuring the progress made or lost.  Anyone who has been in the business, or even been watching for more than a few years knows that the crabs and fish come and go (they come more when they're not fished as hard, but that's a different story), and oysters are a perennial disappointment.  Otherwise, the progressive changes in the bay, if any are smaller than the inter-annual variation, and will be observed only over longer periods.

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