It's not the heat, but this past weekend's rain that could be a major factor behind a fish kill on Lake Arbutus.

The Department of Natural Resources says the dead fish started surfacing on Friday. The DNR says they've seen more than 500 fish, probably dead from bacteria.

After fishermen noticed these crappies cropping up on Lake Arbutus late last week, they told Steve Wiss at the Hatfield Sport Shop. He says he became concerned.

“As the weekend grew, it seems like there's more and more crappies that are floating. There's no sign of any other species that are floating on the lake other than the crappies,” says Wiss.

He contacted the DNR. This morning, a team of biologists took to the water, counting the amount of dead fish and taking samples to test in the lab.

“We're probably looking at that big influx of water that came in and then probably a bacterial outbreak. Almost 99 percent of fish we found were crappies,” says DNR Fish Biologist Dan Hatleli. “Looking at the gills on those fish, it seems it's almost that there may have been a bacterial outbreak. Columnaris is real common, usually when fish are stressed after spawning and the water temperatures are high enough.”

And though this sports shop owner says he's nervous to hear of a fish kill, the DNR says there's still plenty of fish in the lake.

“If we had thousands and thousands and thousands of dead fish out here, obviously we'd be a little bit more concerned,” says Hatleli. “But, then again, this is nothing to sneeze at. But as far as total numbers of fish in the lake, this isn't that significant of a fish kill.”

The DNR says it will have to wait for lab tests to see if the bacteria are the cause of the kill.

Wiss says the cooler water temperatures earlier in the spring may have affected how the crappies spawned this year. But, the DNR says they’ll have to wait until fall to see if it's affected the younger crappie population.