Biological indicators of stream health using macroinvertebrate assemblage composition: a comparison of sensitivity to an urban gradient

2006 ◽  
Vol 57 (1) ◽  
pp. 37 ◽  
Author(s):  
Christopher J. Walsh
Keyword(s):  
Small Area ◽  
Ecosystem Health ◽  
Human Impacts ◽  
Biological Indicators ◽  
Assessment System ◽  
Biotic Index ◽  
Urban Gradient ◽  
Assemblage Composition ◽  
Management Objectives ◽  
Macroinvertebrate Assemblage

Biological indicators are increasingly being used as integrative measures of ecosystem health in streams, particularly indicators using macroinvertebrate assemblage composition. Several indicators of this type have been advocated, including biotic indices based on taxa sensitivities, richness indices and ratios of observed to expected taxa from models predicting assemblage composition in streams with little human impact (O/E scores). The present study aimed to compare the sensitivity of indicators of each of these types (all used for legislated objectives for stream protection in Victoria, Australia) to a gradient of urban disturbance in 16 streams in a small area in eastern Melbourne. The biotic index SIGNAL and number of Ephemeroptera, Plecoptera or Trichoptera families were the most sensitive indicators, whereas total number of families and O/E scores from Australian river assessment system (AUSRIVAS) models were least sensitive. Differences in sensitivity were not the result of sampling or taxonomic inadequacies. AUSRIVAS and similar models might be improved by using only predictor variables that are not affected by human impacts and by sounder approaches to model selection. Insensitivities of indicators and misclassification of sites by the Victorian objectives show that assessment of indicators against disturbance gradients is critical for setting management objectives based on biological indicators.

Protection of in-stream biota from urban impacts: minimise catchment imperviousness or improve drainage design?

2004 ◽  
Vol 55 (3) ◽  
pp. 317 ◽  
Author(s):  
Christopher J. Walsh
Keyword(s):  
Urban Gradient ◽  
Assemblage Composition ◽  
Explanatory Variables ◽  
Urban Impacts ◽  
Macroinvertebrate Assemblage ◽  
Impervious Area ◽  
Drainage Connection ◽  
Drainage Design ◽  
Urban Catchments ◽  
Stream Biota

Urbanisation is a looming global threat to in-stream biodiversity, but the best approaches to mitigation are unclear. This paper asks if the protection of in-stream biota, in particular macroinvertebrate assemblages, is dependent on the sequestration of catchments from urbanisation, or if protection in urbanised catchments can be achieved through better drainage design. In-stream macroinvertebrate assemblage composition was assessed for 16 catchments spanning a rural–urban gradient. Catchment imperviousness and drainage connection (the proportion of impervious area directly connected to streams by stormwater pipes), together with other possible driving factors, were assessed as explanatory variables of macroinvertebrate assemblage composition. The proportion of variance explained independently and jointly by each variable was assessed by hierarchical partitioning. Assemblage composition was strongly explained by the gradient of urban density (i.e. a large proportion of variance was jointly explained by variables correlated with the urban gradient; imperviousness, connection, longitude and elevation). However, drainage connection was the strongest independent correlate. Most sensitive taxa were absent from sites with >20% connection. Thus the connection of impervious surfaces to streams by pipes is a more likely determinant of taxa loss than the impervious areas themselves. Low-impact urban design approaches that reduce drainage connection are postulated as the most effective management solution to the protection of stream biota in urban catchments.

Body size, not other morphological traits, characterizes cascading effects in fish assemblage composition following commercial netting

2005 ◽  
Vol 62 (12) ◽  
pp. 2802-2810 ◽  
Author(s):  
C A Layman ◽  
R B Langerhans ◽  
K O Winemiller
Keyword(s):  
Morphological Traits ◽  
Fish Assemblages ◽  
Human Impacts ◽  
Morphological Characteristics ◽  
Prey Fish ◽  
Geometric Morphometric ◽  
Complex Species ◽  
Predator Prey ◽  
Assemblage Composition ◽  
Cascading Effects

Traits used to group species and generalize predator–prey interactions can aid in constructing models to assess human impacts on food webs, especially in complex, species-rich systems. Commercial netting has reduced populations of large-bodied piscivores in some lagoons of a Venezuelan floodplain river, and cascading effects result in distinct prey fish communities in netted and unnetted lagoons. In 2002 and 2003, we sampled assemblages of prey fishes in netted and unnetted lagoons and tested whether fish size and (or) other morphological characteristics were associated with differences in assemblage composition. In both years, prey fish assemblages in netted lagoons were dominated numerically by larger species. We used geometric morphometric methods to test for a relationship between species morphological characteristics and found that neither overall morphological ordination nor specific morphological traits could be used to distinguish among assemblages. Thus, size was the only variable that was useful in explaining differences in assemblage composition. Even in this species-rich river with a complex food web, size-structured predator–prey interactions apparently influence community-level patterns and can be used to characterize human impacts.

scholarly journals Using an improved interval technique for order preference by similarity to ideal solution to assess river ecosystem health

2019 ◽  
Vol 21 (4) ◽  
pp. 624-637
Author(s):  
Wei Xu ◽  
Zengchuan Dong ◽  
Li Ren ◽  
Jie Ren ◽  
Xike Guan ◽  
...  
Keyword(s):  
Ecosystem Health ◽  
Assessment System ◽  
Ideal Solution ◽  
River Ecosystem ◽  
Interval Numbers ◽  
Aquatic Life ◽  
Morphological Form ◽  
Standard Interval ◽  
Order Preference ◽  
The Mean

Abstract A river ecosystem health (REH) assessment system, based on indicators for morphological form, hydrology features, aquatic life, and habitat provision was established to characterize REH. The standard interval Technique for Order Preference by Similarity to Ideal Solution method (TOPSIS) does not fully consider dynamic changes in REH, so interval numbers and the mean were introduced into an improved version of TOPSIS to achieve a more objective analysis. The improved interval TOPSIS method was tested in the Zhangweinan River and a river ecosystem health integrated index (REHI) was calculated. The REHI decreased from 0.376 to 0.346 over the past 25 years and the REH ranged from general to poor for 1991 to 1995 and from poor to very poor for 1996 to 2000, 2001 to 2005, 2006 to 2010, and 2011 to 2015. The ecosystem health is poor because of dams and reservoirs in the upper reaches that prevent water flowing to the lower reaches, over-abstraction of water, and severe pollution. This method gives objective and accurate assessments of REH and can be used to support decision-making and evaluation in a range of fields.

Using benthic diatom assemblages to assess human impacts on streams across a rural to urban gradient

2015 ◽  
Vol 22 (22) ◽  
pp. 18093-18106 ◽  
Author(s):  
Ying Yang ◽  
Jin-Xiang Cao ◽  
Guo-Feng Pei ◽  
Guo-Xing Liu
Keyword(s):  
Human Impacts ◽  
Benthic Diatom ◽  
Urban Gradient ◽  
Diatom Assemblages

New sensitivity grades for Australian river macroinvertebrates

2003 ◽  
Vol 54 (2) ◽  
pp. 95 ◽  
Author(s):  
Bruce C. Chessman
Keyword(s):  
Water Quality ◽  
Health Program ◽  
Assessment System ◽  
Local Context ◽  
Biotic Index ◽  
Government Agencies ◽  
River Health ◽  
Site Specific ◽  
Eastern Australia ◽  
Family Level

The SIGNAL biotic index for river macroinvertebrates, originally developed and tested in eastern Australia, was revised for application to the entire continent. Macroinvertebrate survey data from the National River Health Program were used to set grade numbers between 1 and 10 to represent the water-quality sensitivities of 210 taxa. Grades were assigned at the taxonomic levels customarily used by government agencies (predominantly family level) and by community groups (mainly order). A new index version using these grades, SIGNAL2, was correlated with water temperature, turbidity, electrical conductivity, alkalinity, pH, dissolved oxygen, total nitrogen and total phosphorus. Because of natural spatial variation in water quality, index scores need to be interpreted in a local context or against site-specific predictions generated by the Australian River Assessment System (AUSRIVAS).

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