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Title: Assessment of Sampling Methods for Macroinvertebrates (RIVPACS) in Deep Watercourses
Author: J A B Bass
Author: J F Wright
Author: R T Clarke
Author: J M Gunn
Author: J Davy-Bowker
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1420, Representation ID: 478, Object ID: 2575
A comparison of deep-water sampling devices for macroinvertebrates was undertaken at six sites throughout England in July/August 1999. The performances of three devices were compared (Yorkshire airlift, Medium Naturalist's dredge and Long-handled pondnet). Six replicate samples were taken with each device at each site. Each replicate sample was collected from a separate target area covering an estimated 1.5 m2 of riverbed. The comparison was confined to deep-water habitats. At the same six deep-water sites a series of six 1-minute replicate samples was taken at the watercourse margin, using the standard FBA pondnet. The range of macroinvertebrates present in the margin samples was compared with those from the deep-water samples at each site. The recommendations of the report are: 1. The airlift sampler is recommended as the most effective device for collecting benthic macroinvertebrates at sites with extensive deep-water habitats; 2. On the basis of results from the present study (at six sites), the total area sampled in deepwater habitats by the airlift should not be less than 4.5 m2; 3. Sampling activity at deep-water sites should take account of the spatial patchiness of habitats and associated fauna; 4. To permit the effective assessment of river quality at deep-water sites, sampling activity should target deep-water habitats but also watercourse margin habitats separately, to both reflect the different range of macroinvertebrates present and aid data interpretation; 5. For margin samples, a 3-minute margin pondnet sample should be taken from accessible bank-side habitats, with the collecting time and effort split in proportion to those habitats; 6; The development of separate RIVPACS modules (deep-water and margin) is necessary for all deep-water sites where the available habitats cannot be sampled effectively with one device; 7. Development of new RIVPACS modules (deep-water and margin) for deep-water sites will require the selection of c.40-50 good quality reference sites. The selection process for reference sites needs to take account of major site variables (eg flow/absence of flow; presence/absence of submerged plants) in the context of regional representativeness; 8. By adopting these recommendations, future sampling at deep-water sites will incorporate the flexibility to: (i) assess deep-water and margin habitats separately, thereby retaining an ability to detect and monitor different forms of stress (ii) restrict sampling to the deep-water or margin habitats, where the use of one of these options is considered adequate on a given sampling occasion (iii) combine the results from these habitats if this is appropriate.
Publisher: Environment Agency
Subject Keywords: Water qualityRIVPACSMacroinvertebratesWater qualityInvertebratesMethodologyCanals
Extent: 119
Total file downloads: 13

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