Editing A11. Riparian Invertebrate Survey (section)

== 2 Method summary  ==

To get an overview of the diversity of riparian beetles a combination of three techniques: hand searching, excavation and pitfall trapping is recommended (Natural England, 2017). Four sampling stations close to each other (200m), usually on sand or shingle bank and associated habitats, should be surveyed. Each one should be surveyed for a one-hour hand-searching, completed by 20 minutes excavation (only on sand and shingle bars). This is complemented by pitfall traps which are buried for 2 weeks within the defined sampling station.

'''Sample station:''' a stretch of river and its associated riparian habitat, including: eroding banks, edges of backwaters, vegetated sand and shingle, riparian woodland, stretches of emergent vegetation, woody material etc.

'''Hand-searching method:''' for each station, 6 searches of 10minutes are undertaken targeting the specific habitats presents. The 10 minutes includes the time to prepare equipment and transferring individuals to collecting tubes. Specific techniques are advised according to the habitats (please see protocol) 

'''Excavation:''' Following the Sadler and Petts (2000) method, the operator digs a 1m² area, located 1 or 2 meters from the river edge, down to the water table.  The sides of the excavation are gradually collapsed down into the water and floating invertebrates are collected. Method should last between 15 and 20 minutes.

'''Pitfall trapping:''' Based on Sadler and Bell (2000), the surveyor buries ten small plastic cups, c. 10cm diameter, in the sediment/soil, so that the rim is flush with the surface. These are filled one third full of a 50:50 mixture of propylene glycol. and water, with a small amount of detergent added to break the surface tension. Pitfall traps are placed in the riparian zone, at least 2m apart in each of the habitat types detected.

Survey should be performed between the first week in May to the last week in June, with mid-May to mid-June being optimal as it corresponds to the peak of beetle activity.
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File:Figure A11RIS1.jpg|Monnow river, 5 pit falls traps - June 2015 © Nick Mott, Staffordshire Wildlife Trust. 
File:Figure A11RIS2.jpg|Dove river, pitfalls and hand searching - 2013 © Nick Mott, Staffordshire Wildlife Trust

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