ANNAPOLIS — An abundance of underwater grasses in the Chesapeake Bay means clearer, cleaner water conditions.
Last year, the Bay grasses saw a decline but fared “better than expected,” according to a report released July 24 by the Maryland Department of Natural Resources.
Despite extreme rainfall in 2018, which can contribute to a reduction in underwater grasses, the aquatic vegetation persisted. At the end of the year, the DNR mapped 50,015 acres of grass in Maryland’s portion of the Chesapeake Bay, the report said.
That’s less than 2017’s record-breaking 62,357 acres, but enough grass for the state to stay on track for its 2025 restoration goal of 79,800 acres.
Since 2012, the DNR said Maryland has achieved 63% of that restoration goal, seeing a net gain of more than 25,500 acres of underwater grasses before last year’s decline.
Maryland DNR Secretary Jeannie Haddaway-Riccio said restorationists are taking their efforts one river at a time, though. She said all or part of eight Maryland rivers surpassed their restoration goals in 2018.
These rivers included the Northeast River and the Chesapeake and Delaware Canal in Cecil County, as well as the tidal fresh portion of the Chester River, the middle Chester River, the western branch of the Patuxent River, the upper Gunpowder River, the Bush River, the upper portion of the Big Annemessex River, and Fishing Bay.
Plus an additional four river segments in Maryland that reached 75% or more of their restoration goals, the report said.
But some waterways, such as large portions of the Potomac and Patuxent rivers, weren’t so fruitful, showing substantial declines in underwater grasses caused by rain-induced muddy conditions.
The report explained underwater grass abundance is important because the vegetation exhibits the quickest response to restoration efforts — meaning it’s a critical progress indicator, as well as a reliable gauge of overall Bay water quality.
The grasses also are responsible for removing harmful nutrients and sediment from the water column, reducing shoreline erosion, providing nursery habitat and protection for species like the blue crab and largemouth bass, and supporting and sustaining migrating waterfowl.
Despite varying progress throughout the state, Haddaway-Riccio said, “The resilience of Maryland’s underwater grasses shows that our commitment to improving the health of the Chesapeake Bay is working and with continued efforts, we are well on our way to achieving our 2025 goal.”
The underwater grasses were mapped during an annual aerial survey, conducted by the Virginia Institute of Marine Science. The survey covered 111 flight lines between May and October 2018.
The aerial imagery was then used to identify the amount and location of underwater grasses in the Chesapeake Bay and tidal tributaries.
Additional aerial and satellite imagery was used to augment the imagery in portions of the Bay that could not be mapped.