Biological quality metrics: their variability and appropriate scale for assessing streams

Abstract

The concept of spatial scale is at the research frontier in ecology, and although focus has been placed on trying to determine the role of spatial scale in structuring communities, there still is a further need to standardize which organism groups are to be used at which scale and under which circumstances in environmental assessment. This paper contributes to the understanding of the variability at different spatial scales (reach, stream, river basin) of metrics characterizing communities of different biological quality elements (macrophytes, fishes, macroinvertebrates and benthic diatoms) as defined by the Water Framework Directive. For this purpose, high-quality reaches from medium-sized lowland streams of Latvia, Ecoregion 15 (Baltic) were sampled using a nested hierarchical sampling design: (river basin fi stream fi reach). The variability of metrics within the different groups of biological quality elements confirmed that large-bodied organisms (macrophytes and fish) were less variable than small-bodied organisms (macroinvertebrates and benthic diatoms) at reach, stream and river basin scales. Single metrics of biological quality elements had the largest variation at the reach scale compared with stream and basin scales. There were no significant correlations between biodiversity indices of the different organism groups. The correlation between diversity indices (Shannon's and Simpson's) of the biological quality elements (macrophytes, fish, benthic macroinvertebrates and benthic diatoms) and a number of measured environmental variables varied among the different organism groups. Relationships between diversity indices and environmental factors were established for all groups of biological quality elements. Our results showed that metrics of macrophytes and fish could be used for assessing ecological quality at the river basin scale, whereas metrics of macroinvertebrates and benthic diatoms were most appropriate at a smaller scale.

Linking organism groups – major results and conclusions from the STAR project

“…These effects are most strongly reflected by fish, benthic invertebrates and benthic diatoms (Hering et al, submitted). This contradicts to some degree with the results of Springe et al (2006), who found macrophytes and fish being more suitable for assessing ecological quality at the river basin scale, whereas metrics of macroinvertebrates and benthic diatoms were more appropriate at smaller scales.…”

“…To tests these conjectures, comparative investigations on the response of different organism groups to stress are needed, which have, for example, been performed in the EU funded project STAR and are described in detail by Johnson et al (2006a, b), Springe et al (2006) and in addition by Hering et al (in press) and Johnson et al (in press). With this paper, we try to transform these results into a more general guidance, with focus on which organism group/groups can be used in biomonitoring.…”

Assessment of an index of biological integrity (IBI) to quantify the quality of two tributaries of river Chenab, Sialkot, Pakistan

“…Quantitative physical, chemical as well as biological standards are needed against which streams/rivers in the region can be compared to determine the influence of cumulative stressor (Radwell & Kwak, 2005). Selection of reference sites was done based on evaluation of the biological, physical habitat and water quality data of streams as suggested by USEPA (2006) and Springe et al (2006). Similarly, Zhu & Chang (2008) also used cumulative data set based on physical, chemical and biological conditions of upper Yangtze River to define reference sites for calculation of biological integrity.…”

Epiphytic, littoral diatoms as bioindicators of shallow lake trophic status: Trophic Diatom Index for Lakes (TDIL) developed in Hungary

“…The EC Water Framework Directive (WFD; EC Parliament and Council, 2000) initiated a number of research focusing on basic concepts (Furse et al, 2006), typology of surface waters (Sandin & Verdonschot, 2006) and various kinds of methodical approaches (Comte et al, 2005;Besse-Lototskaya et al, 2006;Persson et at., 2006;Springe et al, 2006).…”