USGS: Aquatic life declines at early stages of urban development

Sponsored by

RESTON, VA, June 3, 2010 -- The number of native fish and aquatic insects, especially those that are pollution sensitive, declines in urban and suburban streams at low levels of development -- levels often considered protective for stream communities, according to a new study by the U.S. Geological Survey.

"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.

###

Sponsored by

TODAY'S HEADLINES

American Water announces James LaFrankie Scholarship Awards recipients

American Water announced recipients of the 24th annual James V. LaFrankie Scholarship Awards. The awards were distributed nationwide to nine college-bound students of full-time AW employees, who demonstrate an interest in water-related industry occupational fields.

WateReuse allocates $6M in funding for 13 new water recycling projects

The board of directors for WateReuse has approved funding for 13 new research projects valued at nearly $6 million. The projects represent a broad spectrum of issues all designed to improve the treatment, distribution and acceptance of recycled water.

MWD board approves nation's largest water conservation program amid drought

The board of directors for the Metropolitan Water District of Southern California approved the nation's largest turf removal and water conservation program, expected to generate enough water savings to nearly fill Diamond Valley Lake over the next 10 years.

EPA grants BCR Environmental national PSRP Equivalency for biosolids treatment

The Environmental Protection Agency's Pathogen Equivalency Committee announced that it has granted its CleanB process National Process to Significantly Reduce Pathogens Equivalency to BCR Environmental.

FOLLOW US ON SOCIAL MEDIA