Southern steelhead trout return

An unexplained die-off of Southern steelhead trout in Malibu Creek took place last year, with a population of 245 dropping to zero by November. Numbers of the fish have risen to about 32 at the last count in June.

to Malibu Creek after die-off

The cause of the die-off remains unknown. Authorities dismiss an alleged cover-up.

By Ben Marcus / Special to The Malibu Times

One year after a mysterious die-off of nearly the entire population of steelhead trout in Malibu Creek, the resilient, ocean-going fish have returned for the summer of 2007, although their numbers are low.

During the summer and fall of 2006, the Resource Conservation District of the Santa Monica Mountains recorded a “wholesale die-off” of steelhead trout in Malibu Creek. Rosi Dagit, a senior conservation biologist for the RCDSMM, has been conducting stream population surveys in Malibu and Topanga Creeks for several years under grants from the California Department of Fish and Game. She said her group, the Topanga Creek Stream Team, first noticed a decline in the Malibu Creek Southern steelhead population in July last year, when the count dropped from 245 to 182 trout, from a previous survey in May 2006. Dagit and her team became alarmed when the steelhead, as well as other species of fish, all began to turn yellow and their numbers continued to drop throughout the summer, down to 100 in August, then to two in October and then none in November.

Lee Michaelson with Tony Morris reported on the die-off and a possible cover-up in a story for the Topanga Messenger.

“The RCD has come under criticism by some who learned about the die-offs by word of mouth and through leaks from sources within the organization for failing to go public about the die-offs when they were first discovered last summer and fall,” Michaelson wrote in the Messenger. “RCD’s silence has led to speculation that the group was attempting to cover-up the die-off for a variety of putative reasons, among them, retaining steelhead related grant funding or concealing the alleged role of ‘RCD’s use of Round-Up in arundo abatement’ as a source of pollution leading to the deaths.” (Arundo is a reed that overtakes the habitat of native plants, growing as fast as 10 centimeters a day during the winter and becomes a significant fire hazard in the summer.)

Dagit said the allegations are “a bit off the wall, since the granting agency was immediately informed of the problem and the RCD has never used Round Up in Malibu Creek or done an arundo removal project there.

“All relevant agencies were made aware of the problem in July 2006 when it was first noted,” Dagit added. “Also, the RCD prepared a press release in December 2006 once most of the test results were in, but State Parks declined to release it. And they are the landowner.”

The RCD grant to maintain a census of the steelhead population in Malibu Creek ended in March this year, but because of the die-off the summer before, a new grant was obtained to extend the surveys until June.

Roy Stearns, public relations officer for State Parks, in a telephone interview Tuesday, said he went over his notes from the end of the year regarding the issue.

“To my knowledge there was no deliberate attempt to cover up anything, no effort to hide anything,” Stearns said. “What we had was not official; we did not have a stream with all kinds of dead fish up and down [the creek].

“What we had was a sudden decline and then no fish in the stream, no return [of the fish], no fish in evidence.”

Researchers tested the water and found nothing toxic or man-made that could have affected the fish, nor was there any evidence of over fishing, Stearns said. “Water temperatures were OK, and there was no evidence of algae [that would have affected the fish].”

Stearns said since researchers could not identify the cause of the decline in fish, he decided to hold off informing the public until one could be found.

A cause still has not been found, however, the steelhead trout are back.

Counting fish

The end of June, Dagit came home late on a Sunday evening after spending a long day counting steelhead in Malibu Creek.

“Snorkel surveys are done with a team of two to three divers and one observer/data recorder,” Dagit said. “Starting from downstream near Cross Creek Road and ending at Rindge Dam, we carefully enter the pools without disturbing the sediment and any fish. The observer stands where she can see any fish moving in the water that we might scare upstream. In large pools, the divers swim in a coordinated transect, so that we can see the entire width of the pool, and more accurately count the fish. Some of the pools in Malibu are well over 20 feet deep and the size of several Olympic swimming pools put together. In smaller pools, we check under every boulder undercut and small cascade where the small fish like to hang out.”

As of June 25, the natives of Malibu Creek were beginning a slow return.

“It was encouraging to see that there were at least a few young of the year present, as well as some adults,” Dagit said. “But when you compare a total of 32 trout in June 2007 to last July’s 180, you can see we still have a long way to go to recover lost ground with this endangered species. The sad news is that the California Department of Fish and Game, and National Marine Fisheries Service have decided that until the water quality improves, [and] exotic invasive species like the carp, crayfish and New Zealand Mud Snails are removed along with the dam, they are focusing their energies in other streams that have better conditions, like Topanga in the Santa Monica Bay and the Ventura River.”

Although the Pacific States Marine Fisheries Commission grant supporting the Malibu and Topanga Creek research by the RCD ended the last week of June, the Topanga Stream Team will be able to continue their work.

“Our next surveys will not take place until September 2007, supported by a new grant coming from the Sea Grant Program,” Dagit said.