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Sloppy Science

While scientists study, farmers go broke.

May 23, 2011


Families Protecting The Valley Newsletter Tell Your Friends about Families Protecting The Valley

MAY 23 2011

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Denis Prosperi
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Sloppy Science!

It can be discouraging to try to get people's attention about California's water problems when there is so much water everywhere.  We read about the record snowpack, the beautiful waterfalls at Yosemite, the rivers running wild, full reservoirs and possible flooding.  When the average person on the street turns on the tap, water is always there.  So, what's the problem?  The problem isn't this year.  It's next year, and the next year, and the next year.  It's the lack of reliability.  Farmers don't know from one year to the next how much water they'll get.  They don't know what crops they'll plant next year, don't know how the banks will treat them, don't know how many employees they'll hire.  Devin Nunes and Jeff Denham are trying to address this in their Water Reliability Act that's making its way through Congress.  But things take time.  Time wears out a lot of people.  They give up, they sell, or they try to buy more land just to get the water rights with no intention to farm it. 

One of the main reasons there has been a lack of water is the science of water, and science has had a rough go the past year or two.  I think we can say with some certainty that water science isn't an exact science.  The U.S. Fish and Wildlife Service has been lectured by Federal Judge Oliver Wanger to go back to the drawing board regarding their scientific solutions to the delta smelt.  The National Academy of Science has just finished ripping apart the Bay Delta Conservation Plan for its lack of science.  The Delta Independent Science Board identified 42 different stressors in the Sacramento-San Joaquin Delta, but says they can't prioritize them. 

That's why we are amused (Hey! we have to find some humor somewhere!) by articles that perpetuate the confusion.  The article below (Heavy Rainfall May Be Linked to Shark's Deaths) tells the story of all the fresh water flowing into and through the delta and San Francisco Bay.  All we've ever heard from the enviro scientists is that the more fresh water flowing through the delta, the better.  But now, apparently the fresh water is killing leopard sharks.  Or, is it?  Keep reading the article.  State pathologists are studying blood and tissue samples and say the cause "could be anything from low salinity and low dissolved oxygen levels to bacterial infection, virus or man-made contaminants such as pesticides or fertilizers."

Oh!  We get it.  They don't know.  I guess it's not rocket science.  Again, we don't mind scientists trying to do their job.  We just wish they'd allow water to be diverted to farms and Southern California until they figure it out.  Again, it's not about this year; it's about next year and the years thereafter.  While scientists study, farmers go broke.

Heavy rainfall may be linked to sharks' deaths

Kelly Zito, Chronicle Staff Writer


This winter's heavy rains - beneficial to so many species - may, in fact, be diluting saltwater in San Francisco Bay so dramatically that leopard sharks are dying in the very spots where they prefer to give birth and search for food, scientists said Tuesday.

State biologists investigating a rash of leopard shark casualties around the region over the past month think the torrents of freshwater flowing into shoreline lagoons may be throwing the body chemistry of the fish fatally off balance.

"They might be going into these coves to pup," said Carrie Wilson, a marine biologist in Monterey with the California Department of Fish and Game. "If there's more freshwater intrusion and low salinity, it's very tough on these animals."

The analysis is still in the early stages, and there is no conclusive evidence of a connection, but hundreds of leopard sharks and rays also died in 2006, the last year rainfall was this far above normal.

More than 100 dead

More than 100 adult and juvenile leopard sharks have been found dead since mid-April. Early necropsies of a few sharks showed internal bleeding and brain lesions, problems not usually associated with low salinity conditions. However, several scientists and members of the public have reported seeing the animals gasping and thrashing before death, suggesting the sharks could have injured themselves after falling ill.

This week, state pathologists are expected to release the results of blood and tissue samples. Those should shed more light on the cause, which could be anything from low salinity and low dissolved oxygen levels to bacterial infection, virus or man-made contaminants such as pesticides or fertilizers.

Found around bay

The first wave of sharks washed ashore near a residential neighborhood in Redwood City. Since then, dozens of the strikingly patterned bottom-feeders have been spotted along the shores of Foster City, San Francisco and Marin County, according to Sean Van Sommeran of the Pelagic Shark Research Foundation.

Longtime East Bay resident Corky Schweizer observed a shriveled adult leopard shark carcass just south of San Francisco Airport on Saturday morning. He said the animal's remains caught his attention because they were so far above the waterline.

"It basically looked like it had launched itself out of the water," Schweizer said.

Leopard sharks, which can grow 5 feet long and live 40 years or more, are common in the shallow coastal waters from Oregon to Mexico. They typically eat crabs, small fish and mud-dwelling worms.

Prefer salty water

Though they don't venture out into the deep sea, they do favor water with salinity levels at the higher end of the spectrum, said Wes Dowd, a postdoctoral scholar at Stanford University's Hopkins Marine Station in Pacific Grove.

Dowd studied the effect of low-salinity water on leopard sharks as part of his thesis. In his experiments, Dowd found that when salinity fell to 19 parts per thousand, the sharks thrust their noses and fins out of the water in an attempt to survive.

Earlier this spring, sensors in some parts of San Francisco Bay recorded salinity levels below 15 parts per thousand, Dowd said. Seawater salinity maxes out at about 34 or 35 parts per thousand.

"When (salinity) moves lower ... it becomes harder for the sharks to compensate for that change in their environment," Dowd said. "They don't cope well."

Wait for the data

Though Wilson acknowledges the possible link between the deaths and the rapid influx of freshwater, she declined to use the term "die-off" and cautioned against jumping to conclusions until all the data are in.

"There have been some wild speculations based on only a few samples," she said. "We don't want to give out any information that's premature."

Whatever the roots of the problem, shark specialist Van Sommeran suspects that he and his team of volunteers are collecting only a fraction of the ailing animals.

"We found 50 (sharks) in one canal in Redwood City alone," he said. "Now we're getting calls from Millbrae, San Francisco, Mill Valley, Sausalito - it seems that the affected area is expanding."


E-mail Kelly Zito at kzito@sfchronicle.com. 


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