By Alex DeMetrick

KENT ISLAND, Md. (WJZ) — While heat waves like the one we’re currently sweltering in have impacts on land, it’s also being felt on the water.

Alex DeMetrick reports on what the intense heat and lower than normal rainfall are doing to the Chesapeake.

When the sun comes up over the Chesapeake these days, it adds to heat already trapped in the bay’s water and brings another big number to our First Warning Weather.

“The bay temperatures are really quite warm, even for the summer,” said Dr. Donald Boesch.

Boesch studies the bay for the University of Maryland’s Center for Environmental Science.

“The bad news is the conditions in the shallow water are stressful, not only for crabs but for some of the bay grasses,” he said.

Past summers with high heat have seen the decline in the number of crabs caught, as they flee to deeper water for relief. Large beds of grasses have died off in water too hot to survive. What the bay is not seeing are the kind of huge algae blooms that formed with warm water this past spring, which create dead zones.

“Where you get this algae blooming and it depletes the oxygen from the water,” said Severn Riverkeeper Pierre Henaart.

Those blooms were fed by nitrogen and sediment carried into the bay last fall after heavy tropical storms, but now the nutrients that fed the algae have been eaten up, thanks to dry weather.

“The advantage this year is we’ve had very little runoff, very little rainfall, so there’s not as much fresh water coming into the bay which would bring nutrients, which cause the dead zone phenomenon,” Boesch said.

Those conditions have reduced dead zones by two-thirds but also increased the number of sea nettles.

The full extent of the good news/bad news effects on the bay won’t be known until late fall.


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