Science


Catchment Invertebrate Fingerprinting (CIF) Study

In 2014, the Wessex Chalk Stream and Rivers Trust (WCSRT) received significant funding from the Esmée Fairbairn Foundation in support of our pioneering work on catchment-scale river improvement. The rivers benefitting in the first year were the Test, the Itchen and the Hampshire Avon. The fingerprinting research has focussed on insects and other aquatic animals that live on the river bed and react characteristically to particular types of water quality pollution and habitat damage. The intention has been to identify pollution hotspots, which will then be addressed by WCSRT and partners.

The first phase of the work included analyses of long-term (up to 30 year-old) Environment Agency (EA) river quality sampling data on numbers and types of aquatic invertebrates by Dr Nick Everall of the Aquascience Consultancy . These samples were collected by standarised 3-minute kick-samples, which makes them comparable over the years and between rivers.

Maps of the outputs from these studies are presented below. On each map, for each sampling site, indices have been calculated to assess the impact of the following four common river pollution factors:

  • Fine sediment level
  • Flow regime
  • Phosphate enrichment
  • Organic pollution

Also, for each of these indices, an arrow has been added to indicate trends over time; an upwards arrow indicates a worsening effect, downwards an improving effect and level no discernible trend.

Phase 1 Results:
For all three river catchments there are clear widespread indications of adverse impacts on invertebrate communities due to both fine sediment and phosphorus pollution. The sources of these pollutants are likely to include non-mains sewerage, riparian farmland, fish and water cress farms, sewage treatment works and other forms of catchment industry.

Phase 2:
In September 2014, we embarked on the next phase of the project to collect around 55 invertebrate samples and analyse them to species level. This new suite of samples allowed for a finer level of analysis of invertebrate communities (and correspondingly water quality), as the older EA data was largely comprised of samples identified to family or genus, rather than species level. We repeated our sampling programme in Spring 2015 to further refine our understanding of catchment water quality. Autumn and Spring sampling allowed us to include all invertebrate species that emerge at different times of the year.

Next Steps:
We are beginning to identify pollution hotspots and are formulating strategies to address these problem areas via the respective Catchment Partnerships through the Sediment Pathways project.

With help and support from partner organisations, WCSRT is now embarking on a CIF study for the Meon catchment. As with the previous two studies, the EA has supplied historic data from their monitoring sites on the Meon. This long-term data set will be analysed to provide a picture of temporal trends. In addition to the EA data, independent invertebrate samples are also being collected for analysis.

WCSRT intend this project to continue indefinitely and will be seeking funding to enable ongoing annual or biennial sampling across our river systems.

For more information please contact Rupert Kelton, T&I Catchment Officer by email: rupert.kelton@wcsrt.org.uk.

Test and Itchen Maps

To download the maps in full please click here
The full version of the Test & Itchen map booklet can be viewed and downloaded here .

Hampshire Avon Maps

To download the maps in full please click here
The full version of the Hampshire Avon map booklet can be viewed and downloaded here.

River temperature recording

WCSRT temperature loggers monitor the daily warming and cooling patterns of river water at specific sites, particularly through the summer months. Over the years the number of loggers/sites is increasing and provide a useful resource.

Equipment tests

WCSRT loggers are tested for consistency. At 15C most loggers are within 0.05C of each other and the maximum difference between two of the loggers has been 0.1C. Tests are conducted each spring and autumn (2011-2016) and performance is better than the manufacturers claimed accuracy of +/- 0.4C at 20C.

Logging intervals

Generally WCSRT loggers are set to record water temperature every 15 minutes. This period is widely adopted by other organisations using temperature loggers.

File index

The raw data files can be downloaded and WCSRT encourage the sharing of information. Limited summary results appear in our Newsletters. Files are listed separately by year, by catchment, river and named site, with start and end dates of temperature recording in the river. Monthly mean, max and min are added from 2014 onwards. For most files it is advisable not to rely on data before 1st June and after 30th Sept, as some results may represent air temperature when the loggers were put out and retrieved. * Footnotes describe known data anomalies. Please report any additional data anomalies you find to WCSRT. Thank you.

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