The AQEM system
1. classifies a stream stretch in a quality class from 5 (high) to 1 (bad)
2. gives information about the cause of a possible degradation.
As demanded by the Water Framework Directive AQEM applies a stream type-specific approach. Particularly at the European scale this is inevitable, since
e.g. a highland stream in Sweden and a lowland stream in Italy are inhabited by very different macroinvertebrate communities. Therefore, for each stream type
different calculation methods are applied based on the comparison with different reference conditions. However, the system always follows the same evaluation
scheme and each stream-type specific method fits into the general assessment framework. This framework can be defined as follows:
Stressor-specific approach; for each stream type the 'main' degradation factor presently affecting the stream is assessed. This might be acidification
(e.g. in Northern Sweden), degradation in stream morphology (e.g. in Central Europe) or organic pollution (e.g. in Southern Europe). In some cases more than
one stressor is separately assessed and the results of the individual steps are then combined to a final assessment result or the assessment is addressing the
Multimetric system; for each stream type those calculation methods have been identified, which are best at indicating a sites' state of degradation. The
results of the individual calculation methods are then combined in a 'multimetric formula', which is always the same.
The multimetric result is converted into the final score ranging from 5 (high quality) to 1 (bad quality).
| Achieved Objectives:
The AQEM project developed an assessment system (AQEM Assessment System, AAS) for streams in eight European countries based on benthic macroinvertebrates,
which fulfils the requirements of the EU Water Framework Directive. The AAS system classifies a stream stretch into an Ecological Quality Class from 5 (high)
to 1 (bad) based on a macroinvertebrate taxa list, which has been obtained from sampling the stretch using a harmonised method. Furthermore, AAS gives information
about the possible causes of degradation. Based on a stressor-specific approach, for several stream types the main degradation factor presently affecting
the stream can be assessed. For each stream type those calculation methods have been identified, which indicate a site’s state of degradation best. The results
of the individual calculation methods are then combined in a multimetric formula. Converted into a final score ranging from 5 (high quality) to 1 (bad quality)
the multimetric methodology allows the definition of classes representing a gradient from degraded to reference or best-available stream quality
| Product Descriptions:
The AAS provides a scientifically sound assessment method for 28 European stream types, which can be used as a tool to implement the Water Framework Directive.
Though there are necessarily differences between the methods to assess different stream types, the assessment framework is always the same and the same tools
(PC program, taxa list, taxa scores and manual) are applied for all stream types. The applicability of the developed system is ensured by:
1. The AQEM European stream assessment program, which performs all calculations necessary for applying the AQEM system. It includes the calculation of
the Eco-logical Quality Class of a sampling site, based on a macroinvertebrate taxa list, by performing stream-type specific calculations, and a large number
of additional metrics, which are helpful for data interpretation.
2. The AQEM taxa database, which contains more than 9,500 European macroinvertebrate taxa and their autecological specifications, which are necessary
to perform the calculations.
3. The AQEM manual, which describes the whole AQEM procedure, individually the selection of suited sampling sites, the recording of abiotic data, the field
and lab procedures of taking macroinvertebrate samples, the identification, the handling of the data, the use of the AQEM software and the interpretation
of the results.
AQEM available resources
1. Ecological quality assessment calculation tool
Product: software, guideline
2. European macroinvertebrate taxalist