Department of Water Resources
A daily compilation of significant news articles and comment
January 23, 2009
3. Watersheds –
Fall fish count in Delta is dismal
The
Trees dying in the West at record rate
The San Francisco Chronicle
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Fall fish count in Delta is dismal
The
By Matt Weiser
Delta fish continue to hover at the brink of extinction, and conditions could worsen for the estuary and the economy unless winter gets a lot wetter, according to a new state survey.
Native Delta smelt, a threatened fish, is at its lowest point in 42 years of record-keeping. Two nonnative fish, the American shad and threadfin shad, also set record lows.
The findings were in the state Department of Fish and Game's latest fall population survey of Delta fish species, which concluded in December.
Three other species showed slight gains over 2007, but remain well below historical averages: the native longfin smelt and
"When the uncommon ones like Delta smelt and the common ones like threadfin shad both take a nosedive, there's something really wrong," said Bruce Herbold, a biologist who monitors the Delta for the U.S. Environmental Protection Agency. "We're really seeing a massive change."
The health of the Sacramento-San Joaquin Delta is of concern because it is a freshwater source for two-thirds of
Last year, Delta water diversions were slashed about 30 percent to protect fish, bringing a hit of at least $300 million to the economy, according to an estimate by the state Department of Water Resources.
It could get worse this year.
In December, DWR warned water contractors they might get only 15 percent of average Delta water deliveries due to the ongoing drought.
On Wednesday, a DWR planning committee reported the delivery forecast may shrink further, perhaps as low as 5 percent to 9 percent of average.
It is rare to see that forecast shrink mid-winter. It usually grows as storms deepen the
But as DWR Deputy Director Ralph Torres noted,
The report was obtained by The Bee prior to its official release. Torres said a new delivery forecast has not been made, but he confirmed it will likely be less than 15 percent.
"Originally we had planned on doing that (new forecast) by Feb. 15," Torres said. "But we may move that date up, because we don't think any precipitation between now and then is going to change anything."
The water content of the statewide snowpack stood at 57 percent of normal on Thursday. Oroville Reservoir, the main supply for the State Water Project, has nearly reached a record low level.
The report suggests
Could things get that bad?
"It's probably a scenario we have to consider," Torres said.
This could worsen conditions for struggling Delta fish species, and for water quality.
Biologists warn that the Delta is in the midst of a human-caused shift – to a different kind of aquatic habitat, one that holds risks for human and environmental health.
The estuary is changing, they say, into a warmer and more stagnant water body where toxic algae blooms are common. Seasonal shifts in temperature and salinity that once defined and cleansed the estuary are disappearing.
Causes are many, experts say, including urban and agricultural pollution and the introduction of thousands of foreign wildlife species. The Delta has also been managed for decades as a freshwater delivery tool serving the world's eighth-largest economy, ahead of the needs of wildlife and water quality.
"You put them together and you get what I'm calling a train wreck," said Bill Bennett, a UC Davis fisheries ecologist and and Delta smelt expert. #
http://www.sacbee.com/ourregion/story/1567091.html?mi_rss=Our%2520Region
Trees dying in the West at record rate
The San Francisco Chronicle – 1/23/09
By David Perlman
Trees are dying faster than ever in the old-growth forests of California and the mountains of the West, a phenomenon scientists say is linked to rising regional temperatures and the destructive forces of early snowmelt, drought, forest fires and deadly insect infestations brought on by global warming.
Over the past 17 years in some regions - and 25 to 37 years in others - the death rates of mature trees have doubled, the scientists said, raising concerns that the problem goes well beyond the death of trees alone.
"The ultimate implications for our forests and the environment are huge," said Mark Harmon of
As the forests shrink, their capacity to absorb carbon dioxide from industrial lowlands diminishes, which means that more greenhouse gases would be added to the atmosphere, resulting in the acceleration of global warming, the researchers said.
While no trees are immune from the accelerating death rates, the victims are primarily the conifers whose abundance throughout
Leading forest ecologists involved
The research involved nearly a dozen leading forest ecologists who studied mortality rates of individual trees in 76 plots of unmanaged forests, situated primarily in
The increase in death rates for the trees has been "pervasive," said Phillip J. van Mantgem, a forest expert with the U.S. Geological Survey's
"If current trends continue, our forests will eventually become sparser, the ages of our trees will decrease by half, and they will be able to sequester less carbon - further speeding up the pace of global warming," van Mantgem said during a teleconference sponsored by the American Association for the Advancement of Science.
The most likely cause of the increasing deaths, van Mantgem said, is the widespread rise in average temperatures throughout the study regions over the past three decades - an increase of a full degree Fahrenheit and an amount consistent with the global warming measurements and models reported by the world's experts of the Intergovernmental Panel on Climate Change.
Death in Yosemite , Sequoia
Van Mantgem led his own
A powerful influence on the rising tree mortality rates has been increasingly frequent droughts in the High Sierra, where more rain instead of snow has been recorded in recent years and the snowpack has melted earlier, said Nathan L. Stevenson of the USGS forest ecology center, the co-leader of the research group.
"The droughts are lasting longer, and they're helping all those things that like to eat trees," Stevenson said, referring, of course, to all the hungry beetles and their ilk.
The scientists also found that wherever the death rate of the trees has been accelerating, fewer young trees have been replacing them. "Recruitment" is the forest ecologists' term for that succession, and slower recruitment marks another uneasy portent for the future, they warned.
"It's like a human population," Stevenson said. "If deaths among older people were doubling fast and fewer young ones were replacing them - well, if you saw this going on in your own family, it's high time you'd be concerned."#
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/01/22/BAO215D7DF.DTL&feed=rss.bayarea
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