Bay wetlands may face losing battle against sea level rise

December 13, 2011 By Elaine Bible, San Francisco State University
Students in Tom Parker's lab set up an experiment at a salt marsh in Corte Madera, Marin County.

( -- San Francisco Bay's tidal marshes may face a grave threat from sea level rise in the next century, according to a new study published by a group of scientists, including Professor of Biology Tom Parker.

Tidal salt marshes form on the fringes of the Bay. Tall, reed-like cordgrass grows in lower marshes, inundated by the tide twice a day, while salt-resistant succulents are the signature plants of higher marshes, which only get wet during extreme high tides and storms.

These ecosystems are a critical natural resource. They sustain and other wildlife, protect coastlines against flooding, provide nursery areas for and filter pollutants from and the atmosphere.

But the survival of these wetlands depends on a delicate equilibrium between the water level and how quickly sediment is deposited by the seawater. That balance is likely to be thrown off course by over the next century, the researchers found, as accelerated sea level rise outpaces the marshes' ability to build up layers of , mud and minerals.

The researchers found that in the worst case scenario, 93 percent of the Bay’s tidal marsh could be lost in the next 50-100 years if no significant marsh restoration efforts are undertaken. This dire prediction was based on a sea level rise of 5.4 feet and low sediment availability.

"So far, wetlands in San Francisco Bay have been able to keep up with low rates of sea level rise of about 1 millimeter per year, which have increased to 2-3 millimeters per year in the last decade," Parker said. "But the sea level rise predicted for the next century is far greater and the bottom line is that there won't be many wetlands left."

Parker was part of a collaboration of researchers, led by scientists at PRBO Conservation Science, who built a model to predict how rise may impact San Francisco Bay’s tidal marshes. Parker contributed data on how quickly sediment builds up in the wetlands. Since 2003, he has conducted extensive fieldwork in the Bay's tidal marshes, funded by the California Bay-Delta Authority's CalFed program and the U.S. Department of Energy’s National Institute of Climate Change Research.

"The amount of sediment in the water is expected to decline in the future which doesn't bode well for tidal marshes," Parker said, noting that the damming of rivers upstream has reduced the sediment available to replenish marshes.

The study was published Nov. 16 in the online journal PLoS One. The researchers produced an online tool with interactive maps showing where marshes will survive under various scenarios.

Explore further: Bleak future for Bay area tidal marshes?

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not rated yet Dec 13, 2011
Ain't seen nothin' yet boys and girls.

In the next 5 years, expect mean global sea levels to rise by about 0.93 inches.

In the next 10 years, expect mean global sea levels to rise by about 2.79 inches.

The rate of sea level rise is accelerating, and the rate of acceleration is also accelerating.

You won't notice much difference annually, but on time scales of 5 to 10 years, it will become very noticeable.

In a couple decades, you'll be able to go to the ocean and WATCH the sea level rise by like a millimeter per day...
1 / 5 (2) Dec 13, 2011
" the next century." !!!!
that's ca. 90 yrs away - why should anyone believe this waste of public funding nonsense when they can't even accurately predict the weather for next week?

@nanobraino; you'd better go round up Chicken Licken and explain your "sky is falling" paranoia to the king. Maybe he can get you some free psychological counseling or free meds, or both.
5 / 5 (1) Dec 13, 2011
that's ca. 90 yrs away - why should anyone believe this waste of public funding nonsense when they can't even accurately predict the weather for next week

Actually, they CAN accurately predict the weather for next week, and do so on a daily basis with skill greatly exceeding chance.

The NHC predicted every hurricanes track this year almost to perfection. On the 5 day forecast it verified to within 25 miles of the center line, and 6 hours on timing. In several cases, their margin of error on the 5 day forecast was less than the width of the eye-wall of the storm...

The improvements that have been made in the past 10 years in weather forecasting are so good that it's practically spooky.

Sometimes it's as if they had a time machine or something...
5 / 5 (1) Dec 13, 2011
Oh really?

Methane Bomb is starting to hit. Check this article about the Russian Survey of the arctic.


They describe HUNDREDS of recent "kilometers wide" methane fountains spewing methane at 100 times normal concentration.
not rated yet Dec 14, 2011
With that speed of sea level rise wouldn't trapped sediments and organic matter raise the level of vegetation to a great extent allowing the areas to adapt on their own? while an instantaneous rise in sea level may be an issue, the productitivy of these areas should be high enough to adapt to these small levels of changes in water level.

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