The annual Lake Tahoe health report released this week describes a spreading Asian clam population that could put sharp shells and rotting algae on the spectacular mountain lake's popular beaches and possibly aid an invasion of quagga and zebra mussels, say researchers from University of California, Davis and University of Nevada, Reno.

The planet's ocean surface temperature was the warmest on record for July, breaking the previous high mark established in 1998, according to an analysis by NOAA's National Climatic Data Center.

Feedback: Mercury Contamination In Fish

--- From Don A. Essig, Water Quality Standards Coordinator, Idaho Department of Environmental Quality

RE: USGS Study Documents Widespread Mercury Contamination In Fish Nationwide, CBB, 08/21/2009, https://www.www.www.columbiabasinbulletin.org/351355.aspx

Strengthening "El Nino" conditions in the equatorial Pacific in combination with a Pacific Decadal Oscillation "warm phase" pushes up the odds that the Pacific Northwest will experience a winter season warmer and drier than usual, according to the University of Washington's Climate Impacts Group.

An international team of scientists with divergent views on ocean ecosystems has found that efforts to rebuild many of the world's fisheries are worthwhile and starting to pay off in many places around the world. Their study puts into perspective recent reports predicting a total collapse of global fisheries within 40 years.

Scientists have developed a new system to help policy makers better assess the costs and benefits of building dams -- the first system of its kind to use an interdisciplinary approach to simultaneously evaluate the distribution of biophysical, socio-economic and geopolitical impacts of dams, according to one of the study's co-authors.

Climate change is already having visible impacts in the United States, and choices made now will determine the severity of its impacts in the future, according to a new federal study assessing the current and anticipated domestic impacts of climate change.

New research indicates that a warmer climate has a significant effect on the snowpack, as measured by water content on April 1, even if other factors keep year-to-year measurements close to normal for a period of years.

Rivers in some of the world's most populous regions are losing water, according to a comprehensive study of global stream flows.

Renowned marine biologist Jane Lubchenco, an Oregon State University faculty member for more than three decades, was confirmed last week by the U.S. Senate as the under secretary of commerce for oceans and atmosphere. In this capacity, she will serve as the ninth administrator of the National Oceanic and Atmospheric Administration.

Many state and local officials and private organizations are basing decisions -- such as how to build bridges or manage water supplies -- on the assumption that current climate conditions will continue, but that assumption is no longer valid.