Microbiology

From the second half of the 19th century, land reclamation has transformed the Sacramento-San Joaquin Delta (Delta). The landscape of the Delta has gone from a network of shifting waterways and tidal marshland to channels and islands fixed in position by hardened levees.

New projects from coast to coast will advance the research on harmful algal blooms (HABs) in lakes, reservoirs and rivers. The vivid emerald-colored algal blooms are caused by cyanobacteria, which can produce cyanotoxins that threaten human health and aquatic ecosystems and can cause major economic damage.

The Urban Waters Federal Partnership reconnects urban communities with their waterways by improving coordination among federal agencies, particularly those communities that have been disproportionately impacted by pollution or economic distress. The UWFP draws upon Environmental Justice principles—the idea that all people, regardless of race, religion, national origin, or economic station, deserve...

Naegleria fowleri ( N. fowleri ) commonly referred to as the "brain-eating amoeba", is a thermophilic free-living amoeba found in warm and hot surface water that include freshwater ponds, lakes, rivers, and hot springs (Yoder and others. 2010).

Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.

Harmful algal blooms (HABs) are caused by a complex set of physical, chemical, biological, hydrological, and meteorological conditions. Many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of HABs.

Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.

The goals of the Regional Stream Quality Assessment (RSQA) are to characterize multiple water-quality factors that are stressors to aquatic life (contaminants, nutrients, sediment, and streamflow alteration) and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region.

Reconnecting people and water is an increasingly important goal in many urban areas. Parks, urban trails, boat ramps, and urban agriculture all are ways that an urban population can interact with nature and improve quality of life. USGS is participating in gathering the information that will make these projects possible.

Is water quality getting better or worse? Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.

Stream, river, and lake bed sediment are reservoirs for many contaminants. These contaminants include some “legacy” contaminants, like DDT, PCBs, and chlordane, and chemicals currently in use, like the insecticide bifenthrin and many flame retardants. Learn about techniques used to study sediment-associated contaminants and their importance to aquatic biota.

Who lives in your stream? Rivers and streams, even small ones, are teeming with a vast number of species, including fish, aquatic invertebrates, and algae. Stream ecology is the study of those aquatic species, the way they interrelate, and their interactions with all aspects of these flowing water systems.