Underwater Grasses

By providing food and habitat for wildlife, reducing shoreline erosion and improving water clarity, underwater grasses play an important role in the Bay ecosystem.

Underwater Grasses

In 2017, an estimated 104,843 acres of underwater grasses were mapped in the Chesapeake Bay. For the third year in a row, this total marks the highest amount ever recorded by researchers at the Virginia Institute of Marine Science. For the first time in our decades-long history of monitoring this critical habitat, total abundance has surpassed 100,000 acres.


Acres of underwater grasses in the Chesapeake Bay

Researchers attribute the rise in underwater grass abundance to a strong increase in the very salty, moderately salty and tidal fresh regions of the Bay. The very salty waters of the Bay saw a sustained recovery of eelgrass, while its moderately salty waters saw a continued increase in widgeon grass. Because widgeon grass is a “boom and bust” species whose abundance can rise and fall from year to year, a widgeon-dominant spike is not guaranteed to persist in future seasons. The wild celery, water stargrass and other species that have returned to the tidal fresh waters of the Bay are less prone to such changes in abundance. 

While this total is about half of the acreage the nation's largest estuary once supported—and 57 percent of the 185,000-acre goal to which the Chesapeake Bay Program has committed—it is 14,843 acres greater than the partnership's 2017 restoration target. 

A continued rise in bay grasses will benefit the entire Bay ecosystem: underwater grasses absorb nutrient pollution, improve water clarity, reduce shoreline erosion, release oxygen into the water, sequester carbon and provide food and shelter to striped bass, blue crabs and other critters.