Updated analysis shows North Carolina’s seagrass habitat still declining

The amount of seagrass in the state’s estuaries has decreased more than 16% over a 14-year period, according to a new study. 

The Albemarle-Pamlico National Estuary Partnership (APNEP), hosted by the NC Department of Environmental Quality through a cooperative agreement between the state and U.S. Environmental Protection Agency, has published a report showing a net loss in the extent of high-salinity submerged aquatic vegetation (SAV) habitat in North Carolina’s sounds between 2006 and 2020. Also known as seagrass or underwater grasses, this valuable natural resource improves water quality, decreases shoreline erosion, and is an essential habitat for many fishery and wildlife species. The report updates a study released in 2021 by including data from a third survey completed by APNEP and partners in 2020.  

While the data also confirm that the state continues to possess the largest acreage of seagrass along the east coast of the United States – an estimated 88,531 acres – the extent of seagrass meadows in the Albemarle-Pamlico estuary decreased by at least 16,129 acres, or 16.2%, between 2006 and 2020, despite suitable habitat available for expansion. 

Seagrass is declining worldwide, primarily due to water quality degradation, coastal development, dredging, fishing, boating, and other related aquatic activities, sea level rise, warming water temperatures, and tropical cyclones. North Carolina is experiencing annual rates of seagrass loss at or below the global average. 

The decline in North Carolina seagrass was not evenly distributed. In the central portion of the study area, from Hatteras Inlet to Barden Inlet near Cape Lookout, seagrass acreage decreased 2.0% per year compared with a decline of 0.8% and 1.4% per year in the northern and southern portions of the study area, respectively. It is noteworthy that recurring extreme weather events affected North Carolina over the period during which the three surveys were conducted, including 10 tropical cyclones that directly impacted the Albemarle-Pamlico estuary, physically disturbing meadows, water quality and the stability of the barrier island inlets and flood deltas. 

Because seagrass is sensitive to water quality, including nutrient and sediment pollution, a continued decline in the acreage of these underwater meadows indicates that the overall health of North Carolina’s estuaries may be declining. Continued mapping of seagrass is essential to clarify the status and long-term trends of this resource in North Carolina. Additionally, integration of seagrass mapping with other collaborative environmental monitoring programs is critical to identifying and managing the causes of seagrass decline. 

The data analyzed for this report were collected using three aerial surveys from 2006-2007, 2013 and 2020. APNEP and partners have since intensified and expanded seagrass monitoring efforts, completing new subregional surveys of the Albemarle-Pamlico estuary from 2021 to 2025. Analysis of these survey data are underway and will enable APNEP to provide more details on seagrass status and trends in the Albemarle-Pamlico estuary. 

These findings provide guidance for the development of protection and restoration strategies for the region’s underwater grasses, including conservation and management actions supported by the N.C. Coastal Habitat Protection Plan. 

The Albemarle-Pamlico National Estuary Partnership is a collaborative program dedicated to understanding, protecting, and restoring the Albemarle-Pamlico estuarine system in North Carolina and Virginia. Designated as an estuary of national significance by Congress in 1987, it is one of the oldest and largest programs in the U.S. Environmental Protection Agency’s National Estuary Program.