Lake Research That Isn't All Wet

October 2, 2009
Sergio Sañudo-Wilhelmy, left, and Douglas Capone received a National Science Foundation grant to study the nutrient cycle of three lakes in California and Nevada. Photo credit Taylor Foust.

( -- The federal government may not have been able to save California from massive budget cuts, but at least a stimulus research grant will help scientists understand the biology of western lakes.

USC College biologists Douglas Capone and Sergio Sañudo-Wilhelmy will use $535,000 from the National Science Foundation to study the nutrient cycle of three lakes in California and Nevada.

As world authorities on the and trace metals, respectively, Capone and Sañudo-Wilhelmy hope to pinpoint how a lesser-known metal — — affects a lake’s productivity.

The project is relevant to anyone who has ever water-skied, fished or swum in algae-choked waters.

An excess of nutrients leads to eutrophication, the term for unchecked plant growth in a body of water. The plants consume all oxygen in the water, killing fish while creating thick mats of vegetation.

The opposite problem, a dearth of nutrients, also may limit the fish and game that live off a lake.

Nitrates and phosphates from human activities often drive the nutrient cycle. But in remote lakes with few sources of natural or artificial nutrients, trace metals such as molybdenum may be the limiting factors, Capone said.

In such places, small variations in metal inflows could cause big changes in a lake’s biology.

“By understanding these subtleties, you may be able to prevent eutrophication,” Capone said.

His team’s overall goal, he added, is “to understand controlling factors in the primary productivity of each of these [lake] systems.”

The three lakes are nutrient-poor Castle Lake, near Mt. Shasta in Northern California; Lake Tahoe, which used to be nutrient-poor but has begun to change with increased runoff from human activities; and Walker Lake in Nevada, a nutrient-rich on the verge of eutrophication.

Expected to last two years, the project will test the researchers’ hypothesis that molybdenum is a key factor in the uptake of nitrates and nitrogen fixation by algae in these lakes.

Nitrogen-fixing microbes obtain their nitrogen directly from the air. They are able to live in nutrient-starved waters, but they need key trace metals. Capone and Sañudo-Wilhelmy believe that molybdenum is as important to nitrogen fixation in lakes as iron is for the same process in areas of the open ocean.

The project, funded by a grant from the American Recovery and Reinvestment Act, will create full-time positions for a laboratory technician and a graduate student. Another two technicians and five graduate students will spend part of their time on the project.

Provided by USC College

Explore further: Controlling nitrogen pollution will not stop toxic algae blooms, says research

Related Stories

Researchers find key to saving the world's lakes

July 21, 2008

After completing one of the longest running experiments ever done on a lake, researchers from the University of Alberta, University of Minnesota and the Freshwater Institute, contend that nitrogen control, in which the European ...

Amazon powers tropical ocean's carbon sink

July 21, 2008

Nutrients from the Amazon River spread well beyond the continental shelf and drive carbon capture in the deep ocean, according to the authors of a multi-year study.

Recommended for you

The world needs to rethink the value of water

November 23, 2017

Research led by Oxford University highlights the accelerating pressure on measuring, monitoring and managing water locally and globally. A new four-part framework is proposed to value water for sustainable development to ...


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.