Some anglers initially suspected foul play, but it appears that the fish died before spawning because of the stress caused by a combination of bacterial gill disease and the sudden drop in water in a crowded stream. The DFG staff and volunteers found hundreds of dead fish again on October 23, so they traveled over to the Little Truckee River to collect 275,000 kokanee eggs.

In addition to the kokanee salmon, three resident brown trout were also killed in the creek between the Highway 89 Bridge and its entrance into Lake Tahoe. Some DFG staff estimated that between 3,000 and 5,000 kokanee were killed, while another source estimated it was "over 2,000 fish."

"Our diagnosis is that the fish died from bacterial gill disease, coupled with spawning stress and low flows in Taylor Creek," said Tom Modem, DFG fishery pathologist. "The mortality occurred after flows were reduced on the creek."

"As long as I've worked at the hatchery, we haven't seen any event like this before," noted Dennis Redfern, manager of the DFG's American River Fish Hatchery. "It appears to be a case of lots of fish without much water. Some of the dead fish were already spawned out, while others were not."

The good news is that in spite of the fish kill, the DFG and Project Kokanee volunteers were able to meet their quota of 1.2 million eggs for the year, in addition to getting 300,000 eggs from Lake Paulina in Oregon.

"There are a lot of fish spawning now in the Taylor Creek system," added Redfern, "and kokanee were spawning successfully again last week when we took our second batch of 686,232 eggs."

The kokanee salmon run on Taylor Creek this season is estimated to be a whopper 30,000 to 60,000 fish, so there is no shortage of fish in the creek, in spite of the fish kill. Taylor Creek is the key spawning tributary for Lake Tahoe's kokanee salmon, though good numbers of fish also spawn in the Little Truckee River.

The fish kills were preceded by the release of 9 cfs into the creek during the annual Kokanee Festival on October 13-14. After the festival was over, the federal agency dropped the flows to 4-1/2 cfs.

Apparently, the Forest Service employee in charge of raising the flows at the time of the festival raised them more than he was expected. "He said he was letting out 5 cfs, but I told him it looked more than 9 cfs, so he dropped the flows back down," stated Michael St. Michel, the visitor center director.

There is an agreement between the DFG, U.S. Forest Service and the Fallen Leaf Lake Homeowners Association, a result of a court ruling to provide for minimum flows of 4-1/2 cfs after October to allow kokanee salmon and brown trout to spawn in the creek. The higher flows aren't allowed before October 1 because the homeowners around the lake were concerned about their docks being left high and dry.

Stafford Lehr, the DFG fishery biologist dispatched to the scene, emphasized that "no blame has been assigned to the fish kill. It's a function of environmental factors. The Forest Service did drop releases to 4-1/2 cfs after the festival, but nobody knew that the fish had abnormal bacterial levels when the flows were dropped columnaris bacteria was also found, but not in high levels."

Lehr said that the Forest Service reduced the flows from Fallen Leaf to extend the flows for fish spawning in this low water year. "There is a limited bank of water and they did not want to withdraw it," said Lehr.

"We were originally concerned that the fish kill might be a toxic dumping event, but we concluded that it wasn't after examining the fish in the laboratory," explained Lehr. "If it had been a chlorine discharge, for example, there would have been burning on the gills."

"The amount of fish now in Taylor Creek is above the carrying capacity," added Lehr. "The fish now are often spawning on the redds made by previous spawners. There are abnormally high numbers of kokanee in the creek this season."

The fish kill on Taylor Creek is not the only one that has taken place in northern California this fall. During the same week that the Taylor Creek kill took place, thousands of threadfin shad and catfish, along with some king salmon, perished on the San Joaquin River near Mossdale. No specific cause had been determined at press time on the San Joaquin, though sewage discharge, combined with low water conditions, was suspected by state and federal officials.