Urban Riverfly


Urban Riverfly is an extended list of the original ARMI aquatic invertebrates that can be used across a number of different river systems. The addition of six invertebrate groups to the original eight used in the basic ARMI scheme provides greater sensitivity and evaluation of pressures. The extra groups comprise of: worms, snails, beetles, leeches, blackfly larvae (Simuliidae) and freshwater hoglouse (Asellidae). The 14 groups now include easily identifiable, more pollution tolerant and commonly recorded invertebrates, especially in urban and modified rivers.

Scores are also impacted both positively and negatively by abundance, therefore are more reflective of the EA methodology (WHPT). Pollution tolerant groups such as leeches, worms and freshwater hoglouse will negatively affect the score as abundances increase. A pilot of this scheme was started in the Midlands where both new and existing volunteers were provided with one days training. The survey method remains the same as the traditional ARMI with a 3 minute kick sample and 1 minute hand search.


Environment Agency, ZSL

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