Climate Change Alters Base of Tahoe Food Web

Sep 29, 2008
Climate Change Alters Base of Tahoe Food Web

(PhysOrg.com) -- UC Davis researchers at Lake Tahoe this week published the first evidence that climate change alters the makeup of tiny plant communities called algae, which are the very foundation of the web of life in freshwater lakes.

Other scientists had predicted that climate change would reduce the overall amount, or biovolume, of an important algae group called diatoms. However, the UC Davis researchers found that the warming of the lake changed not the overall biovolume but rather the relative populations of various diatom species.

"There are greater numbers of small-sized diatom species in recent years than there were 20 years ago," said postdoctoral researcher Monika Winder, the study's lead author.

"Changing climate conditions, such as warmer air temperatures, have changed the mixing patterns of the lake," explained study co-author Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center. "With less mixing, it is difficult for larger algae to stay suspended at the surface of the lake, where there is light to facilitate their growth. This allowed the smaller diatoms, which sink more slowly, to proliferate."

Diatoms form the base of the food chain in large bodies of water, both freshwater and saltwater, around the world. The hugely abundant, single-celled plants are eaten by tiny animals (zooplankton), which are eaten by small fish, which are eaten by bigger fish and birds, and so on to the highest predators in the system.

"It is inconceivable that you could alter the base of the food web and not have other things start changing," Winder said. "What those changes will be, we don't know yet."

Some zooplankton species may decline, which would lead to declines in fish numbers. Clarity may also be reduced because smaller algae stay at the surface longer, scattering light and making the water appear greener.

Schladow noted that this particular finding was possible because of the uncommonly long and detailed record of physical and biological measurements made by UC Davis at Lake Tahoe for the past 50 years.

The new study, titled "Lake warming favours small-sized planktonic diatom species," was published online on Sept. 24 by the journal Proceedings of the Royal Society B. The research was funded by UC Davis and the agencies that have supported the Lake Tahoe Interagency Monitoring Program (LTIMP).

Also a co-author of the study: John Reuter, associate director of the UC Davis Tahoe Environmental Research Center.

Provided by UC Davis

Explore further: Climate rhetoric faces devil in the detail at Lima talks

add to favorites email to friend print save as pdf

Related Stories

Lake Tahoe clarity improves, outlook not so clear

Aug 08, 2013

While clarity improved at Lake Tahoe for a second straight year in 2012, long-term trends show that climate change is impacting the Lake Tahoe Basin with drier years, less precipitation, higher lake temperatures ...

Lake Tahoe water clarity the best in 10 years

Feb 28, 2013

(Phys.org)—Lake Tahoe's clarity improved in 2012 for the second year in a row, and its waters were the clearest in 10 years, according to University of California, Davis, scientists who study the lake. ...

Five acres of mats for Tahoe Asian clam project

Oct 17, 2012

Rubber barriers bound for the lakebed of Lake Tahoe's Emerald Bay are being assembled at the University of California, Davis, as part of the biggest Asian clam control project in the lake's history. UC Davis scientists, staff ...

Recommended for you

Gold rush an ecological disaster for Peruvian Amazon

13 hours ago

A lush expanse of Amazon rainforest known as the "Mother of God" is steadily being destroyed in Peru, with the jungle giving way to mercury-filled tailing ponds used to extract the gold hidden underground.

Australia out of step with new climate momentum

15 hours ago

Australian Prime Minister Tony Abbott, who rose to power in large part by opposing a tax on greenhouse gas emissions, is finding his country isolated like never before on climate change as the U.S., China ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Modernmystic
2.5 / 5 (8) Sep 30, 2008
LOL it may REDUCE fish populations because the base of the food chain has increased. These are the kids in school who picked their noses incessantly and couldn't color inside the lines until the fifth grade....

They just can't admit that something positive could come from climate change. It's like a holy proclamation of their religion...

Thou shalt not admit a warmer Earth could be good in ANY way.

deepsand
2.3 / 5 (6) Oct 01, 2008
LOL it may REDUCE fish populations because the base of the food chain has increased.

WTF?
These are the kids in school who picked their noses incessantly and couldn't color inside the lines until the fifth grade....

So, you know these people personally?
They just can't admit that something positive could come from climate change. It's like a holy proclamation of their religion...

Non sequitur
Thou shalt not admit a warmer Earth could be good in ANY way.

Thou shalt not speak specious BS.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.