Chesapeake Bay’s dead zone shrinks

The dead zone of the Chesapeake Bay — sometimes covered in red and brown algae and deadly to fish — is shrinking, according to a recent study by the Maryland Department of Natural Resources and Old Dominion University.

The oxygen-depleted zone stretches from the middle of the bay near Baltimore to around Mobjack Bay near Gloucester County.

The progress means the bay is getting healthier for aquatic life and safer for humans. Dead zones, which occur when too many algae bloom, can make people sick if they swim in the water. The shrinking dead zone leaves more room for fishing and outdoor recreation.

Dead zones occur when pollution, such as fertilizers and dog waste, gets into the bay. Its high levels of nitrogen and phosphorus can cause algae to bloom.

When the algae die, they sink and decompose, sucking oxygen from the water faster than plants can replenish it. The vegetation dies and fish and other animals that rely on it will suffocate or have to migrate to an area with more oxygen.

Dead zones expand and contract throughout the year and are linked to spring rainfalls that wash pollutants into waterways. Warmer temperatures can help dead zones grow and make them last longer.

Virginia and the other states along the bay are working under the Chesapeake Clean Water Blueprint to decrease the pollution. The dead zone has been shrinking as cities have improved the facilities that filter wastewater into the bay.

While the commonwealth is on track to reduce pollution from wastewater, it is behind in reducing agricultural and stormwater runoff, according to the foundation.

The blueprint calls for about 90% of the remaining pollution reductions to come from agriculture.

The Inflation Reduction Act and the U.S. Department of Agriculture also provided funding this year for farmers to put in forested buffers and wetlands at little to no cost. The buffers trap much of the runoff before it can enter the bay.

Under the reduction act, farmers can get help in using conservation practices such as reducing fertilizers and using no-till or limited-till farming through organizations such as the Environmental Quality Incentives Program.