Excess Rain Waters Bay Grasses

An interesting case of science reporting by press release. VIMS released it's annual report on the state of submerged aquatic vegetation in the Bay, and other outlets picked up the news. First, VIMS: Survey indicates slight decline in underwater grass abundance

Despite record-rainfall in 2018, underwater grass abundance remains strong
An annual survey led by researchers at the Virginia Institute of Marine Science mapped an estimated 91,559 acres of underwater grasses in the Chesapeake Bay and its tidal tributaries in 2018.

While this acreage is less than the previous year, it is likely that substantially more submerged aquatic vegetation (SAV) grew in the Bay than the mapped acreage suggests: frequent rain, cloudy water, and security restrictions prevented researchers from successfully collecting aerial imagery over 22% of the monitored area, including the Potomac River near the Patuxent Air Base; portions of the Susquehanna Flats; Mattaponi, Middle, Choptank, and Honga rivers; and Fishing Bay.

In 2017, these unmapped portions of the Bay supported more than 17,401 acres of grasses. Adding this value to the 2018 estimate would bring the estimated total for 2018 to 108,960 acres—a 4% increase from 2017 levels and a 59% achievement of the Chesapeake Bay Program’s 185,000-acre 2025 goal. The 2017 total was the greatest amount of underwater grasses ever recorded by VIMS’ SAV Monitoring and Restoration Program, and the first time total grass abundance surpassed 100,000 acres. VIMS scientists began monitoring the Bay in 1979. . . . 

As reported by the Bay Journa (EPA Bay Programs bought and paid for media arm) is less optimistic: Bay grasses survived 2018 deluge, but losses expected this year

The full impact of last year’s high flows on the Chesapeake’s underwater grasses, one of the Bay’s most critical habitats, remains murky as scientists try to assess the full impact of last year’s record rainfall.

But the full story is far from clear. Most of that survey was finished before unrelenting rains began in late July. The continual downpours flushed huge amounts of water-clouding sediment and nutrients into the Bay, which can be lethal to grass beds.The good news, according to the results of the 2018 aerial survey, is that underwater grass acreage increased overall from 2017 in areas where the survey was completed.

Scientists say grasses stressed by poor conditions last year may not bounce back this summer. As a result, the impact of those high river flows may not be known until after the 2019 survey is complete.

“Everyone is wondering what will happen in 2019 and how these plants will react,” said Bob Orth, the Virginia Institute of Marine Science researcher who has been overseeing the aerial survey since its inception in 1984. . . .

The local CBS station in Balmer is really upbeat:  Measured Acreage Of Underwater Grasses Decline Slightly In The Bay, But Could Be Highest Amount Ever

In 2018, an estimated 91,559 acres of underwater grasses were mapped in the Chesapeake Bay and its tidal tributaries.

While this acreage is less than the previous year, it is likely that substantially more submerged aquatic vegetation (SAV) grew in the Bay than the mapped acreage suggests.

If the acreage of grasses that these unmapped portions of the Bay supported in 2017 is considered, the estimated total for 2018 could be as high as 108,960 acres.

This would be an increase from the previous total, which was the highest amount of underwater grasses ever recorded in the Bay since monitoring began over 30 years ago.

Experts believe it is likely that the actual expanse of underwater grasses in 2018 ranged between 91,559 and 108,960 acres.

The growth and survival of underwater grasses are sensitive to the impacts that extreme weather conditions have on Bay water quality. In the past, underwater grass populations have taken several years to recover from the effects of hurricanes or high-temperature events. . . .

The same basic facts, with three different spins.