Recent data on the health of underwater grasses, as reported in the Bay Journal, showed both improvement and decline in 2024. (https://marylandmatters.org/2025/08/11/underwater-grasses-hit-record-in-lower-chesapeake-bay-last-year/). Underwater grasses are both an important indicator of the health of a water body and a significant contributor to that health. Outcomes vary considerably year to year as they are influenced by rain, temperature, and pollution, particularly from sediment.
The upper and lower Bay saw significant expansion in 2024 but the mid-Bay, especially on the Eastern Shore witnessed a decline that outweighed the gains. The Chester and Corsica rivers are considered in the low salinity, or oligohaline zone, which overall saw an increase by 46 percent.
Data on Bay-wide grasses comes from aerial surveys conducted by Virginia Institute of Marine Science. The aerial photos show where the grass beds are located but volunteers go out in small boats to the identified areas and “ground truth” or identify SAV species found there. ShoreRivers volunteers, including volunteers from CRC, collect data to support the aerial measures with on-the-ground monitoring efforts.
For example, surveys in June 2025 of Gray’s Inn Creek and Robin Cove showed the presence of:
Volunteers monitor their survey areas at least twice per year. Next time you are on the water, take a look.