GRAPEVINE -- More than 124,000 fish died at Lake Grapevine this week as this summer's nonstop heat severely depleted oxygen levels, an official with the Texas Parks and Wildlife Department said.
"There were lots of dead fish stacking up at the Silver Lake Marina," said Tom Hungerford, a fisheries biologist for the agency. The marina is at the southeast end of the lake near the dam.
Almost all the dead fish were threadfin shad, biologist Melissa Dudley said.
Threadfin shad are small -- often used as bait -- and are rarely more than 6 inches long, according to the wildlife department.
"Less than 1 percent of the fish observed were game fish," she said, noting that the estimate is based on a sample of the fish killed.
Hungerford listed other dead species as gizzard shad, bluegill, white bass, freshwater drum, largemouth bass, smallmouth bass and white crappie.
Low oxygen Monday and Tuesday killed the fish, he said. On Tuesday, when temperatures reached 103 degrees at nearby Dallas/Fort Worth Airport, the hypoxia, or oxygen depletion, level was 1.2 parts per million.
"Anything under 3 parts per million and you start to see fish die," Hungerford said.