Toxic Delta Algae - More Problems?

[Martinez_Mitch]

I understand the toxic delta algae is again present, but I haven't seen any warnings, or PR's on it?

A friend that fishes Brannon Island at the swim beach, observes the DFG netting bait fish numbers ocassionally.

This year they are keeping some of the shad, because they believe they might be having problems after eating this algae.

Also, one of the Wardens waders had a leak, and he had an immediate reaction from from this, as my friend was present.

Any one have any more info out there?

 

[Flutterby]

About a month ago I saw it in Piper Slu, but now it has moved out that area. Between cooler temps and entering salt water, the algae will be killed off for the season. It will probably return next summer, usually in August. If we have dry, warmer then usual winter/spring, it will probably be worse next summer.

IMHO

 

[Martinez_Mitch]

I guess my point here is, when they build their canal, the stagnation problem will get worse.

I got an email reply from Marty Gingras of the Bay/Delta region bio, and they've been looking at this at it applies to to the smelt, shad, etc. (POD species).

When the canal is built, this, as well as the egeria densa, will become worse. And have they addresssed it? The algal blooms were not discovered toxic until maybe 2003 (initially algae '99, not toxic until '03?), but highy toxic tag came in '03/'04 - don't quote me.
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excerpts of the email from Marty:

You are probably talking about the algae named Microcystis aeruginosa. As part of the Pelagic Organism Decline research some folks have been studying it for the last several years. There is an old report here and you can probably find more on the web by searching for the name (in quotes):

http://calwater.ca.gov/science/pdf/workshops/POD/CDFG_POD_Microcystis_biomass_and_toxicity.pdf

Our concerns are mostly what effect it might have on delta smelt, longfin smelt, and striped bass. In high-enough concentrations fish stop eating when in its presence.
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From a Past Press Release:

Contra Costa Times
Effects of toxic algae in Delta unknown
Tuesday, October 18, 2005
Mike Taugher

A highly toxic algae is now growing in the Delta, a drinking water source for 23 million Californians.

Scientists and health officials are studying the potentially carcinogenic algae -- the first toxic algae ever recorded in the Delta -- to determine whether it poses a serious threat to human health and to determine if it plays a role in the Delta's ongoing ecosystem crash.

So far, state and local officials say the water distribution systems that rely on the Delta have not been affected and the water remains safe to drink.

"People shouldn't be terrified, but it is a serious issue," said Peggy Lehman, a senior scientist at the California Department of Water Resources who recently received a $500,000 grant to investigate the algae in the Delta.

"These very large colonial blooms are not that common," Lehman said, adding, "What we want to know is, is it increasing either in mass or toxicity?"

The algae, called Microcystis aeruginosa, is common around the globe but its toxicity ranges from mild to severe. It was first discovered in the Delta in 1999 and determined to be a highly toxic variety in 2003.

Swimmers and others who come in direct contact with Microcystis-contaminated water can sustain anything from minor eye irritation and skin rashes to permanent organ damage and death.

Lehman cited a study that showed Microcystis can cause liver tumors and cancer.

Karen Schwinn, associate director for the U.S. Environmental Protection Agency's water division in San Francisco, said water utilities have not expressed alarm about the algae, but added that state and federal water quality officials in California do not yet have a full grasp of the threat it poses.

"You're raising a question that we at EPA don't know the answer to, and we should," Schwinn said.

The Delta is a source of drinking water for 23 million Californians from the Bay Area to San Diego, adding urgency to investigations into the severity of the algae invasion and how to deal with it. The toxin could be removed at treatment plans that purify Delta water, although the byproducts of treatment can create a separate set of contaminants.

To date, no health problems associated with Microcystis in the Delta or in the drinking water supply have been reported, according to Beth Jines, a spokeswoman for the State Water Resources Control Board.

That may be, in part, because it usually grows in still water and near the surface -- away from the pumps that siphon water out of the Delta

"Intakes for public drinking water systems are in deep, flowing water. To date, there has been no effect on those systems," said Lea Brooks, a spokeswoman at the state Department of Health Services.

"The water is safe to drink. That's the main message: The water is safe to drink," Brooks added.

Still, Microcystis has the potential to render water dangerous.

Three weeks ago, for example, the U.S. Environmental Protection Agency and state and tribal agencies issued a warning to avoid all contact with water from the Klamath River near the Oregon border because of Microcystis.

Blooms in the Delta have not grown severe enough to warrant a similar warning, but health officials and water agencies are taking the threat seriously.

They have scheduled a Nov. 8 workshop on Microcystis in Sacramento.

"Until we understand the science, we'd rather err on the cautious side," said Jines. "What we know (now) is it is toxic and dangerous."

Microcystis, which was first detected in the Delta in 1999, looks like pea-green cornflakes. In severe blooms, it can form a surface scum or mat. Microcystis mats have not yet appeared in the Delta, Lehman said.

Still, swimmers and others who get wet in the Delta should watch out for lesser blooms and report to local health officials any skin rashes, nausea or diarrhea that develops after being in the water, she added.

At the Contra Costa Water District, the only major urban water agency that gets nearly all of its water directly out of the Delta, Microcystis toxins have never been detected in treated water.

But the toxins occasionally enter the district's water treatment plants, though never at levels high enough to exceed World Health Organization guidelines, even if the water were left untreated, said CCWD assistant general manager Greg Gartrell.

The district employs "taste profilers" at its drinking water plants to help detect algae in the drinking water before instruments can.

Beginning in 2003, Lehman and others received funding to study the algae and found it was widespread throughout the Delta.

Monitoring this year showed more Microcystis in the Delta than last year. Scientists do not have enough data to determine if that increase signifies a trend.

In addition to posing a threat to human health, scientists suspect Microcystis might play a role in an ongoing ecological mystery in the Delta.

Beginning in about 2001, populations of several open-water fish species and their food sources began crashing.

No one knows why. Among the many possible explanations for the crash is the possibility that Microcystis toxins could be getting into the food web.

But another possibility is that whatever is causing the ecological crash is also allowing Microcystis to bloom.

Lehman urged caution until definitive answers are available.

"People need to be careful and be aware. We'll know more about (the effect on) drinking water and the food web in another couple of years," she said, adding, "It's not something we can sit back and ignore."

 

[yzer]

Thanks for the info, Mitch.

I saw an average amount of toxic algae this season. The algae like still, fresh water and the warm temperatures found in shallow water. It also needs plenty of nitrates in the water as food. Ag and suburban run-off are the biggest contributor of the nitrates.

A new canal would reduce flow on the Sacramento River between Antioch and Three-Mile Slough: that's the area where toxic algae has reached it highest concentrations in the past.

 

[Flutterby]

Thanks for the additional information! I thought it was a just a concern to us humans in high concentrations. This may be the science we need to stop the canel and more delta gates!