SALT LAKE CITY — A toxic algae bloom closed a popular reservoir in east-central Utah to fishing, boating and swimming on Wednesday, and will likely keep it closed through the Labor Day weekend.

Thousands of small fish called chubs have died in the area affected by the bloom on the Scofield Reservoir, which is about 40 miles from Price, authorities said.

Toxin levels around the bloom are at least five times greater than what is considered safe, Southeastern Utah Environmental Health Director Brady Bradford said. The closure is expected to last through the holiday weekend.

The reservoir supplies drinking water to about 15,000 people in the area, but toxin levels are low to non-detectable in the part of the lake where the drinking water is drawn from, he said. The treatment plant is also equipped to clean water with ozone, which is “the perfect treatment for this situation,” Bradford said.

Scofield Reservoir is a popular fishing spot, and two nearby campgrounds were booked up for the holiday weekend, he said. The campgrounds remain open, though the lake restrictions could put a damper on turnout.

The blue-green algae can cause rashes and vomiting as well as release toxins that can cause nerve and liver damage. It can also be harmful to pets and livestock that drink the water. Algae blooms can contribute to oxygen-deprived dead zones where fish can’t survive.

The restrictions comes after a massive algae bloom last month closed Utah Lake, which is still dealing with elevated bacterial algae levels.