HARRISBURG, Pa. (AP) — Trout season in Pennsylvania opened Monday in an abrupt announcement by the Pennsylvania Fish and Boat Commission that was designed to preempt big gatherings of anglers and travel that typically occurs on the traditional April opening day.

Monday was two weeks ahead of the previously scheduled opening day.

Meanwhile, Chester County launched a plan to test thousands of first responders and other essential workers for coronavirus-fighting antibodies in their blood. A federal judge is also ordering the release of more immigration detainees in Pennsylvania.

Here are the latest coronavirus-related developments in Pennsylvania:

TROUT SEASON BEGINS

Even though trout season is now open, anglers and boaters must abide by social distancing guidelines provided by the U.S. Centers for Disease Control and Gov. Tom Wolf, the Fish and Boat Commission said.

“The trout we have been stocking have had time to spread out, and so should you,” Tim Schaeffer, the agency’s executive director, said in a statement.

The Fish and Boat Commission nonetheless urged anglers and boaters to limit travel by fishing close to home, cover their faces with a mask or some other cloth covering, keep a distance of at least six feet from others, only go fishing with family members living in the same household and never share fishing gear with others.

Not all waters have been stocked, and the Fish and Boat Commission said it will not provide a stocking schedule or a list of stocked waters to further discourage group gatherings.

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RELEASING IMMIGRATION DETAINEES

A federal judge ordered the immediate release of 22 people who were being held in civil detention by U.S. Immigration and Customs Enforcement at county jails in Pennsylvania while they await final decisions of their immigration cases.

The 22 people held in prisons in York County and Pike County each suffer from chronic medical conditions and face “an imminent risk of death or serious injury if exposed to COVID-19,” Judge John E. Jones wrote in Tuesday's decision.

Their release is effective for two weeks.

In a separate decision in recent days, Jones also ordered the release of 13 others held in the prisons in which he wrote that, “in times such as these, we must acknowledge that the status quo of a mere few weeks ago no longer applies."

In Tuesday's decision, Jones wrote that there is “clear evidence that the protective measures in place in the York and Pike County prisons are not working.”

“We can only expect the number of positive COVID-19 cases to increase in the coming days and weeks, and we cannot leave the most fragile among us to face that growing danger unprotected,” Jones wrote.

The released detainees must self-quarantine for two weeks, Jones wrote. He gave ICE one week to argue why the detainees' release should not last longer than two weeks.

The U.S. holds around 37,000 people in immigration detention. Detainees and advocates say many are vulnerable because of age and pre-existing medical conditions, and because they are often held in open rooms, beds 3-feet apart, and without adequate supplies of masks or other protections.

In addition to Pennsylvania, immigrant advocates have filed lawsuits in California, Maryland and elsewhere.

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BLOOD ANTIBODY TESTS

To fight the spread of COVID-19, Chester County will start test the blood of essential workers in an effort to determine who has developed coronavirus antibodies and can fight off the disease.

The tests will be administered to emergency responders, prison staff, health care workers and long-term care facility staff in Chester County, officials said.

County officials acknowledge that the accuracy of such testing is unclear.

The county has received a shipment of 10,000 blood test kits and expect a second shipment of 10,000 to arrive next week. With 307 confirmed cases, Chester County is in the middle of the pack of Pennsylvania's counties in terms of number of confirmed cases per 100,000 residents.

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PRISONERS MAKING MASKS

State prison inmates have so far manufactured more than 180,000 cloth masks for use by Corrections Department staff and the prisoners themselves.

The prison system said Tuesday that its garment factories began converting to mask production on March 17. Each employee has received three masks, each prisoner two.

The prison system’s manufacturing arm, Pennsylvania Correctional Industries, is also making gowns, anti-bacterial soap and disinfectant, the department said.