Publications

Integrating science into resource management activities is a goal of the CALFED Bay-Delta Program, a multi-agency effort to address water supply reliability, ecological condition, drinking water quality, and levees in the Sacramento-San Joaquin Delta of northern California. Under CALFED, many different strategies were used to integrate science, including interaction between the research...

Studies of the effects of urbanization on stream ecosystems have usually focused on single metropolitan areas. Synthesis of the results of such studies have been useful in developing general conceptual models of the effects of urbanization, but the strength of such generalizations is enhanced by applying consistent study designs and methods to multiple metropolitan areas across large...

We examined associations of fish assemblages and fish traits with urbanization and selected environmental variables in nine major United States metropolitan areas. The strongest relations between fishes and urbanization occurred in the metropolitan areas of Atlanta, Georgia; Birmingham, Alabama; Boston, Massachusetts; and Portland, Oregon. In these areas, environmental variables with...

In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment

In this paper, we show that the complex geological evolution of Valles Marineris, Mars, has been highly influenced by the manifestation of magmatism (e.g., possible plume activity). This is based on a diversity of evidence, reported here, for the central part, Melas Chasma, and nearby regions, including uplift, loss of huge volumes of material, flexure, volcanism, and possible...

The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural irrigation. Filtered ground water samples...

Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in...

The age of ground water in any given sample is a distributed quantity representing distributed provenance (in space and time) of the water. Conventional analysis of tracers such as unstable isotopes or anthropogenic chemical species gives discrete or binary measures of the presence of water of a given age. Modeled ground water age distributions provide a continuous measure of...

Evaluating six main rivers and six lakes in Beihuan water system (BWS) and diagnosing the limiting factors of eco-health were conducted for the ecohealth assessment and ecological restoration division of urban water system (UWS) for Beijing. The results indicated that Jingmi River and Nanchang River were in a healthy state, the degree of membership to unhealthy were 0.358, 0.392...

Glen Canyon Dam, located on the Colorado River in northern Arizona, has affected the physical, biological and cultural resources of the river downstream in Grand Canyon. One of the impacts to the downstream physical environment that has important implications for the aquatic ecosystem is the transformation of the thermal regime from highly variable seasonally to relatively constant year...

Earthen levees of three isolated salt ponds known locally as the Alviso Island Ponds were intentionally breached in March 2006 to allow tidal exchange of the ponds with water from Coyote Creek. The water exchange transformed the previously fishless hypersaline ponds into lower salinity habitats suitable for fish life. This study documented fish utilization of the ponds, adjacent reaches...

Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3000 ng/g; median of 6.1 ng/g) were generally greater than those for...