نتایج جستجو برای: bioassessment

تعداد نتایج: 217  

Journal: :Environmental monitoring and assessment 2007
Juanita Bacey Frank Spurlock

This project was designed to establish baseline aquatic biological community structure and physical habitat conditions in select wadeable streams within the California Central Valley. A secondary objective was to evaluate possible water quality differences between site types and seasons. Two agricultural and two urban streams were monitored in spring and fall for two consecutive years beginning...

2013
Emma Göthe

Streams and rivers only contain a small proportion of the Earth’s freshwater, but nevertheless harbour much biodiversity. Headwater streams are the most prevalent running water environments, but despite their wide distribution, they are often excluded from important freshwater legislation and national monitoring programmes. This thesis investigated biodiversity patterns of benthic macroinverteb...

2012
Stefano Larsen Laura Mancini Giorgio Pace Massimiliano Scalici Lorenzo Tancioni

Although anthropogenic degradation of riverine systems stimulated a multi-taxon bioassessment of their ecological integrity in EU countries, specific responses of different taxonomic groups to human pressure are poorly investigated in Mediterranean rivers. Here, we assess if richness and composition of macroinvertebrate and fish assemblages show concordant variation along a gradient of anthropo...

2010
Haibo Wan Christopher J. Chizinski Christine L. Dolph Bruce Vondracek Bruce N. Wilson

The index of biotic integrity (IBI) is a commonly used bioassessment tool that integrates abundance and richness measures to assess water quality. In developing IBIs that are both responsive to human disturbance and resistant to natural variability and sampling error, water managers must decide how to weigh information about rare and abundant taxa, which in turn requires an understanding of the...

2006
Brandon K. Doan Patrick A. Hickey Harris R. Lieberman Joseph R. Fischer

Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this coll...

2008
George M. Ogendi Robyn E. Hannigan Jerry L. Farris

Natural and anthropogenic release of metals into surface waters and sediments may alter benthic community structure. To better understand macroinvertebrate communities in metal-impacted shale-draining streams in north-central Arkansas, sediment and macroinvertebrate samples were collected from sites on black shale-draining (BLS) and limestone-draining streams (LMS; used as a reference stream). ...

2010
ARTHUR C. BENKE

—Wood plays a major role in creating multiple invertebrate habitats in small streams and large rivers. In small streams, wood debris dams are instrumental in creating a step and pool profile of habitats, enhancing habitat heterogeneity, retaining organic matter, and changing current velocity. Beavers can convert sections of free-flowing streams into ponds and wetlands by killing trees and build...

2001
Michael H. Paller Marcel J.M. Reichert John M. Dean John C. Seigle

From 1985 to 1988, stream and riparian habitats in Pen branch and Four Mile branch began recovering from deforestation caused by the previous release of hot water from nuclear reactors. The Pen branch corridor was replanted with wetland trees in 1995 to expedite recovery and restore the Pen branch ecosystem. Pen branch, Four Mile branch, and two relatively undisturbed streams were electrofished...

Journal: :Environmental toxicology and chemistry 2004
Daniel J Cain Samuel N Luoma William G Wallace

Although the differential responses of stream taxa to metal exposure have been exploited for bioassessment and monitoring, the mechanisms affecting these responses are not well understood. In this study, the subcellular partitioning of metals in operationally defined metal-sensitive and detoxified fractions were analyzed in five insect taxa. Samples were collected in two separate years along an...

2011
Ben Labay Adam E. Cohen Blake Sissel Dean A. Hendrickson F. Douglas Martin Sahotra Sarkar

Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence infor...

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