“When the area of driveways, parking lots, streets and other impervious cover reaches 10 percent of a watershed area, many types of pollution sensitive aquatic insects decline by as much as one third, compared to streams in undeveloped forested watersheds,” said Tom Cuffney, USGS biologist. “We learned that there is no ‘safezone,’ meaning that even minimal or early stages of development can negatively affect aquatic life in urban streams.”
As a watershed becomes developed, the amount of pavement, sidewalks and other types of urban land cover increases. During storms, water is rapidly transported over these urban surfaces to streams. The rapid rise and fall of stream flow and changes in temperature can be detrimental to fish and aquatic insects. Stormwater from urban development can also contain fertilizers and insecticides used along roads and on lawns, parks and golf courses.
"Stream protection and management is a top priority of state and local officials, and these findings remind us of the unintended consequences that development can have on our aquatic resources," said Tom Schueler, Chesapeake Stormwater Network coordinator. "The information has been useful in helping us to predict and manage the future impacts of urban development on streams and reinforces the importance of having green infrastructure to control stormwater runoff and protect aquatic life."
USGS studies examine the effects of urbanization on algae, aquatic insects, fish, habitat and chemistry in urban streams in nine metropolitan areas across the country: Boston, Mass.; Raleigh, N.C.; Atlanta, Ga.; Birmingham, Ala.; Milwaukee-Green Bay, Wis.; Denver, Colo.; Dallas-Fort Worth, Texas; Salt Lake City, Utah; and Portland, Ore.
These USGS studies also show that land cover prior to urbanization can affect how aquatic insects and fish respond to urbanization. For example, aquatic communities in urban streams in Denver, Dallas-Fort Worth and Milwaukee did not decline in response to urbanization because the aquatic communities were already degraded by previous agricultural land-use activities. In contrast, aquatic communities declined in response to urbanization in metropolitan areas where forested land was converted to urban land, areas such as Boston and Atlanta.
Comparisons among the nine areas show that not all urban streams respond exactly the same. This is mostly because stream quality and aquatic health reflect a complex combination of land and chemical use, land and storm-water management, population density and watershed development, and natural features, such as soils, hydrology, and climate.
These USGS studies represent an integrated approach to understanding urban streams that includes physical, chemical and biological characteristics associated with urbanization. This is critical for prioritizing strategies for stream protection and restoration and in evaluating the effectiveness of those strategies over time.
For more information, listen to USGS Corecast Episode 127. The full report and extended video podcasts are available at the National Water Quality Assessment program urban studies website.
Kara Capelli | EurekAlert!
Stagnation in the South Pacific Explains Natural CO2 Fluctuations
23.02.2018 | Carl von Ossietzky-Universität Oldenburg
First evidence of surprising ocean warming around Galápagos corals
22.02.2018 | University of Arizona
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy