Bay grasses expand to greatest extent in more than 30 years - Scientists caution that volatile widgeon grass is behind most of rebound
The Bay’s underwater grass meadows, a critical habitat for crabs and juvenile fish, expanded last year to the highest levels seen since monitoring programs began more than three decades ago.Which might make it the best year since Hurricane Agnes set off the decline of seagrasses in the bay back in 1972 by drowning most of them in mud.
The gains were widespread, from high-salinity waters in the lower Chesapeake to tidal fresh areas in its uppermost reaches. A number of areas had more grass acreage than had ever been observed, and scientists found isolated patches in places they had never seen grasses before.Is this another sign the Bay is turning the corner? When I was out with Pete on the Eastern Shore earlier this week, we saw lots of grass, so this may also be a good year coming up. What of it that I collected on my hook looked like Widgeon Grass, but I'm no expert.
The 91,631 acres photographed during the annual aerial survey is nearly half of the Bay Program goal. It also exceeded the 2017 restoration objective two years ahead of schedule — as long as the grasses hang on this year and next.
That’s far from certain, because much of the increase was in the Mid Bay, an area dominated by widgeon grass, a species notorious for its year-to-year fluctuations. Grass beds there more than doubled from 2012 through 2015, and account for more than half of the entire Bay’s acreage.
“Widgeon grass continues to be the story of the Bay in terms of what’s driving these numbers,” said Bob Orth, a scientist with the Virginia Institute of Marine Science who oversees the annual survey.
Orth also cautioned that there were signs of an eelgrass die-back in the lower Bay last fall — something that would not show up until this year’s survey.
Overall, though, the news was good. Grasses increased 21 percent from 2014 levels and have expanded 140 percent since the first survey found just 38,227 acres in 1984 — the lowest ever observed in the Chesapeake.