Why did 1,000 pounds of fish die in a Fremont Lake?

( KRON ) — More than 1,000 pounds of fish died at Lake Elizabeth in Fremont this week, a city official told KRON4. Officials said fish in the lake were breathing one-fifth of their normal oxygen levels.

Fremont Director of Communications and Legislative Affairs Geneva Bosques said the deaths are due to the heat. There are usually fish deaths as the weather warms up, but this week’s deaths were more than usual, she said.

“The fact that we are not getting the afternoon and evening cooldowns we historically experience here in Fremont is exacerbating the problem and not allowing the water temperature to drop and partially improve overnight,” a tweet from the City of Fremont said.

Bosques said the heat brought the oxygen levels from its normal level of 5.0 to below 1.0. Fish typically die when levels drop below 2.0.

City staff were alerted to the situation on Wednesday. Staffers began cleaning up the dead fish that day and have continued making rounds throughout the week.

Bosques said the lake is just four feet deep at its deepest areas. More water was added to the lake to maintain the water level and bring down water temperature.

On Thursday, an outside specialist evaluated the situation. The city is testing to see if other factors like algae and bacteria are at play.

“The City will continue working with our consultant and partners to come up with long-term options and solutions that can help us manage these extreme weather and climate change impacts including the use of pumps and other devices to assist with improved water circulation and monitoring. There are also long-term capital projects being discussed that could increase the depth and flood capacity of the lake,” the city posted.

The city adds 300-1,000 pounds of catfish and trout to the lake every April for a fishing event.

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