State scientists are updating wetlands maps, a project that allows them to see how many wetlands acres the state has lost in the past 15 years, when the last maps were produced.
Recent Supreme Court cases have lifted federal protection from certain nontidal freshwater wetlands, known for their ability to filter harmful pollutants from groundwater. Some scientists are concerned rolling back federal protection may harm the waterways scientists and others worked hard to protect.
Chris Bason, science and technical coordinator for the Center for the Inland Bays, said, “We have made progress in one area, but may be going backward in others.”
The federal changes apply mostly to isolated waterways that cannot be defined as navigable, said Amy Jacobs, scientist in the Department of Natural Resources and Environmental Control Watershed Assessment Section. They have been being filled in for various projects, including farming, road building and development. Under federal regulations, freshwater wetlands could be filled in, but a permit was necessary to do so, said Bason.
Staffing shortages in the U.S. Army Corps of Engineers have hampered enforcement, said Jacobs.
Scientists are still working to determine to what degree freshwater wetlands are losing their nutrient-filtering capabilities, Bason said.
It is difficult to compare the efficiency of freshwater wetlands and saltwater marshes in nutrient removal, said Bason.
Now, scientists are working with grant money to determine how much wetland has been lost in recent years. State maps are based on 1992 aerial photographs, said Jacobs. New maps will use 2007 aerial photography.
She said as scientists work to see how wetland acreage has changed, they can determine which wetland areas were filled in with permits and which were not permitted.
The concern over wetlands use goes beyond whether the marsh areas were altered legally.
When people change wetlands, it reduces their ability to filter nutrients – and that increases pollution to the Inland Bays.
To help meet state goals for nutrient reduction, the state implemented a pollution control strategy, mandating vegetated buffers along waterways, in October.
Those regulations have been challenged in court by Sussex County and the Positive Growth Alliance.
Delaware’s successful campaign to reduce nutrient pollution from farms reaching sensitive waterways has been under way for nearly a decade. Bason said scientists are becoming concerned recent rollbacks in protections for freshwater wetlands could slow some of the progress made by the agricultural industry.
The Nutrient Management Act, passed in 1999, aimed at limiting fertilizer runoff, has successfully reduced surplus nutrients applied to farm fields to increase yield. If farmers put more fertilizer on their fields than plants take up, those nutrients can wash away and wind up in local watersheds, where high levels of nutrient pollution cause fish kills and other disasters.
Scientific reports say while surpluses from farm fields have decreased over the last 11 years, they still exist.
Nutrient management conference
The Center for the Inland Bays will host a conference, Frontiers in Nutrient Management: Sources and Solutions in the Inland Bays watershed, Wednesday, Jan. 28, at the Atlantic Sands Hotel and Conference Center in Rehoboth Beach. For more information or to register to attend, visit inlandbays.org.
