What Do Dead Zones Do? They Kill Fish & Crabs.

Published: August 23, 2019

Here’s a sad story about why dead zones are a bad thing for the Severn River and the Chesapeake Bay. Our pal Ted found that 5 crabs and 5 Perch he was holding in a livebox overnight were dead the next morning (Aug. 21).

Cause: Dead Zone in Little Round Bay.

These fish and crabs suffocated in water that did not have enough oxygen to sustain them in the livebox resting on the bottom of the river.

Normally, a livebox is a wonderful place to hold your catch.

But on Tuesday night, a storm rolled through the area and the winds from the storm caused a great mixing of the waters, spreading the dead zone’s low-oxygen water through out Little Round Bay – and ultimately smothering the fish and crabs under Ted’s pier.

The Deadly Details

Just yards away from Ted’s pier is our Palisades Beach water quality monitoring station where our WQ volunteers track low oxygen conditions every week.

On Wednesday morning, we tracked a dead zone there that was two meters tall (from the bottom) where the water had an oxygen content of between 0.09 mg/l to 1.30 mg/l from 3 meters to the bottom at 4.5 meters.

Fish need at least 5 mg/l of oxygen or greater to thrive. Crabs need 3 mg/l or more.

When that low-oxygen dead zone rolled through, Ted’s catch suffocated.

You can view Ted’s video of the fish/crab kill here: https://www.facebook.com/ted.delaplaine/videos/10220020435570763/