| Title: |
REBECCA WP4 Rivers. Deliverable D6: Report on existing methods and relationships linking pressures, chemistry and biology in rivers
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| Resource Type: |
document --> technical publication --> report
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| Country: |
EU Projects
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| Year: |
2005 |
| Availability: |
Rebecca Consortium (2005) REBECCA WP4 Rivers. Deliverable D6: Report on existing methods and relationships linking pressures, chemistry and biology in rivers.
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| Author 1/Producer: |
Rebecca Consortium
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| Author / Producer Type: |
EC Project
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EUGRIS Keyword(s): |
Water resources and their management -->River basins
Water resources and their management -->Water resources and their management Overview
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| Short description: |
The review of literature on relationships between physical/chemical quality elements in rivers and
biological quality elements has identified thousands of publications on these issues. Therefore the
first main conclusion is that there is a general and very substantial knowledge on the different
types of pressures (types of pollution), on the physical and chemical characteristics and on the impacts
on river plant and animal life.
For all the important types of pressures studies have been made and described in the literature
based on either scientific experiments or environmental monitoring. This has generated a general
and widespread understanding of the general ecological impacts of the different types of pressures
among both scientists and managers with the authorities.
However, most studies did not cover the entire causal chain including pressures, physical/
chemical quality and biological quality. Most studies have been empirical in nature and all
three elements (pressure, physical/chemical quality and biology) have almost never been treated
in a quantitative manner. In the vast majority of studies one element has been assessed quantitatively
while the other two elements have only been qualitatively assessed. Such studies have given
us a useful understanding of general relationships, but will not enable us to establish doseresponse
relationships that could be used as a tool in the implementation of the WFD.
Another difficulty in establishing causal relationships from pressures to the river flora and fauna is
that multiple pressures dominate in rivers in populated catchments where most pollution studies
have been undertaken. Further, only limited conclusion can be made from laboratory experiments,
because they can not easily be up-scaled to entire river ecosystems and catchments, and targeted,
large scale scientific pollution experiments have not been made.
For these reasons the quantitative relationships found in literature between the biota/biological
quality indicators and physical/chemical parameters are rather few compared to the needs for the
authorities implementing the Water Framework Directive. Furthermore, there is an apparent lack
of studies investigating recovery processes after a stressor has been reduced or removed. This limits
our ability to predict how river quality will be improved after reducing a pressure on the ecosystem.
The next task of the REBECCA WP4 work on rivers is to analyse and describe these relationships
based on information found in literature and especially from available monitoring results from
rivers covering both biological and chemical/physical quality elements. With the very large number
of possible biological quality metrics, the large number of different river types in EU and the
different types of pressures this is still a very ambitious task.
With the focus of producing indicators, relationships and classification tools of practical use for the
authorities in their implementation of WFD two important aspects of the strategy for this work are
to focus on
• pressure-impact relationships with a direct linkage between the physical/chemical quality and
the biota and
• indicators and metrics describing the biological quality that can be rather generally applied and
not limited to be useful for one or a few types of rivers.
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Submitted By:
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Dr Stefan Gödeke WhoDoesWhat?
Last update: 28/09/2006
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