STOCKTON, Calif. -- Thousands of dead fish have gone belly-up along the deep water channel in downtown's McLeod Lake.

The tides have left hundreds of dead fish high and dry on the boat ramps, leaving the carcasses rotting in the sun.

The California Department of Fish & Game hasn't determined the cause for the deaths. However, Stockton Municipal Utilities blames the fish kill on lack of oxygen in the channel caused by the rainfall.

"There are a lot of storm lines that drain into this water body ... and what can happen is there is organic material on the bottom of the channel and that can get kicked up and that can greatly decrease the amount of dissolved oxygen in the channel," Mark Madison from the city of Stockton said.

Fishermen have seen the trend before.

"I guess that first runoff that we had, the first rain, all the chemicals from the street, the oil and all that probably got in the water. The runoff killed the shad," Mario Bustamante said.

Since the storm, the city has activated bubblers in the channel used to control algae growth, but will also circulate the water and add oxygen.

Last year, a significant fish kill along the Smith Canal in Stockton occurred in October right after a heavy rainfall.