LURAY, Va. (WFXR) — The National Park Service (NPS) has closed all streams at Shenandoah National Park to fishing in an effort to protect native brook trout, and to ensure the long-term health of fish populations in the park.

The NPS says the closure is the result of hot dry conditions that have caused stream levels to drop, water temperatures to rise, and dissolved oxygen levels to fall. Those conditions are stressing fish, and catching them, especially brook trout, could kill them.

The closure affects all streams and rivers in the park. It will be lifted once stream levels rise and it is determined fish health will not be at risk.

Brook trout are the State Fish of Virginia. They are the only salmonid species native to the commonwealth. Biologists say they are holdovers from the last ice age. They require cool, highly-oxygenated waters like the streams found in the mountains of western Virginia.