BALTIMORE (WJZ) — Dead zones are a sign the Chesapeake is in trouble—and most every summer, one appears in the bay.
Alex DeMetrick reports this year’s dead zone is bigger than normal.
Summer heat is the final ingredient to make a dead zone. Algae—which are microscopic plants—bloom in it, wringing oxygen out of the water as they die and decay.
“If you’re a clam or an oyster, that’s not good news. If you’re a fish, you can certainly move to areas where water has more oxygen,” said Tom Parham, Department of Natural Resources.
But not all make it out alive.
The loss of oxygen can happen quickly, especially when algae explode in confined areas, like Baltimore’s Inner Harbor. in the bay, the scale is far larger.
“Dead zones typically appear in the deepest part of the bay. In Maryland’s portion of the bay, it’s the Bay Bridge down to the state line. Right now, due to our higher than normal spring flows, we’re expecting a slightly larger than normal dead zone,” Parham said.
The heavy rains in spring washed nutrients like nitrogen—a by-product of car exhaust and air pollution—off hard surfaces, into storm drains that ultimately made it to rivers and the bay. Runoff also carried fertilizer and animal waste from farms, all of which fed the algae.
The dead zone cycle fired up with more food than normal.
“The bulk of it is due to the amount of excess nutrients that are coming into the bay or polluted runoff,” Parham said.
Cooler weather in the fall will eventually shrink the dead zone—but not before a summer’s worth of damage is done.
Drought years typically produce the smallest dead zones but come at the cost of lost crops and sometimes water rationing.
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