Urban impacts on phosphorus in streams

Aug 11, 2011

Although phosphorus is an essential nutrient for all life forms, essential amounts of the chemical element can cause water quality problems in rivers, lakes, and coastal zones. High concentrations of phosphorus in aquatic ecosystems are often associated with human activities in the surrounding area, such as agriculture and urban development. However, relationships between specific human sources of phosphorus and phosphorus concentrations in aquatic ecosystems are yet to be understood. Establishing these relationships could allow for the development, implementation, and evaluation of management strategies to reduce nutrient pollution.

Scientists from Washington State University-Vancouver and the University of California-Davis have investigated the link between human sources of phosphorus and in rivers draining into California's Central Valley. Agricultural activity and human population density data was used to estimate the annual input of phosphorus from human sources to watersheds in the Central Valley for the early 2000s. The scientists then compared these estimates with data on phosphorus concentrations in rivers draining the watersheds from 2000 to 2003. Results from the study were published in the August issue of the . This study was funded by California SeaGrant, the US Geological Survey, and NASA.

The research revealed that the majority of phosphorus input from human sources was located in a very small area in most of the studied. Additionally, estimates of phosphorus inputs from fertilizer and , rather than phosphorus input from human sewage, better predicted dissolved forms of phosphorus in rivers than generic data on agricultural and urban land use types in watersheds. The form of phosphorus in rivers is important, as different forms can have different environmental impacts.

"Establishing relationships between human sources of nutrients and nutrient concentrations in rivers is of interest because they may help to develop management strategies for reducing nutrient runoff to the environment," said Dan Sobota, who conducted the study along with John Harrison and Randy Dahlgren.

Research is ongoing at Washington State University-Vancouver and the University of California to find the link between human sources of nutrients in watersheds and aquatic nutrient levels. Further research is needed to examine how relationships between human sources of nutrients and aquatic nutrient concentrations change in other regions, and with different types of land use practices.

Explore further: Rising ocean acidity threatens sea life

More information: View the abstract at www.crops.org/publications/jeq/articles/40/4/1290

Provided by American Society of Agronomy

5 /5 (1 vote)
add to favorites email to friend print save as pdf

Related Stories

Tracking phosphorus runoff from livestock manure

Jun 14, 2010

Nutrient runoff from livestock manure is a common source of agricultural pollution. Looking for an uncommon solution, a team of scientists has developed an application of rare earth elements to control and track runoff phosphorus ...

Study probes sources of Mississippi River phosphorus

May 06, 2011

In their eagerness to cut nitrogen and phosphorus pollution in the Mississippi River and Gulf of Mexico, people have often sought simple explanations for the problem: too many large animal operations, for instance, or farmers ...

Double trouble for water life

May 18, 2009

Excess phosphorus and nitrogen produced by human activities on neighboring land is making its way into our coastal waters and degrading both water quality and aquatic life. Although historically the priority has been to control ...

Recommended for you

Bladderwrack: Tougher than suspected

2 hours ago

The bladderwrack Fucus vesiculosus is actually one of the most important species of brown algae along the North Atlantic coasts. But for years their populations in the Baltic Sea were declining. Looking for the reasons, biolog ...

Australia set to pay polluters to cut emissions

13 hours ago

Australia is set to approve measures giving polluters financial incentives to reduce emissions blamed for climate change, in a move critics described as ineffective environmental policy.

User comments : 0

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.