Sediments in Delaware's Rehoboth and Indian River bays, and rivers such as the Broadkill and Mispillion are causing ignored, untold damage to their ecosystems. Using a common tool to measure transparency in these waters, a Secchi disk, the device can disappear below the surface in barely 8 inches. The use of a plankton net for sampling the productivity of these same waters is impractical. The nets quickly fill with sand, crushing most of the captured microscopic animals (zooplankton) and algae (phytoplankton) beyond recognition.
Setback buffer zones are commonly used to filter out sediment and nutrients from runoff into critical waterways. Salt or freshwater marshes or any other vegetation that binds the bank soils greatly improves the quality of drainage water and benefits downstream farmers, residents and visitors.
Water clarity is basic to the growth of tiny organisms - phytoplankton - that are at the base of the food chain. Using sunlight, they produce oxygen, nutrients and convert carbon dioxide into organic compounds. These then serve as food for larval crabs and other zooplankton that in turn feed fishes and larger marine animals.
Digging long ditches on agricultural lands may slow and collect runoff, but ditches do not compete with the benefits of properly created buffer zones. Some of the nutrients and possible toxins that the ditches accumulate can then percolate down into the aquifers, the source of our drinking water.
The state of Virginia requires 100-to-200 feet setbacks for any intermittent and perennial streams.New Jersey requires areas of 150 feet around resource value wetlands and a minimum of 50 feet in other cases.
In Maryland, setbacks and buffers are generally established by county or city ordinance. Baltimore County requires setbacks of 150 feet around any stream.
The First State's setbacks are regulated by its counties as merely property setbacks. Among its neighboring states, Delaware unfortunately ranks as the Last State in creating buffer zones for the protection of our waterways.
Robert Bachand
Milton