Procambarus crayfish control: Create barriers

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Key messages

  • A before-and-after study conducted between 2007 and 2010 in Spain found that the use of concrete dams across a stream, specifically designed with features to prevent red swamp crayfish from crawling over them, were effective at containing spread of the population upstream.


About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A before-and-after study from 2007 to 2010 in a mountain stream in Italy (Dana et al. 2011) found that building a series of small dams stopped migration of the red swamp crayfish Procambarus clarkii. The invasive crayfish did not penetrate into previously uninhabited areas upstream beyond the lower dams. In addition, numbers dropped below detectable levels in previously occupied areas in the mid reaches between dams. Dams were 1.5–2 m high and 6 m wide and constructed from reinforced concrete. Several design features discouraged crayfish from climbing over including vertical walls, smooth mortar, vertical wing-walls 3.5 m along the banks, and a projecting rim (crayfish are unable to walk upside down on a smooth surface). A flat stony platform was built downstream of each dam to create a shallow area with no refuges, discouraging crayfish from lingering near the dam. Crayfish populations were monitored for 30 days between July and October each year.

    Study and other actions tested
Please cite as:

Aldridge, D., Ockendon, N., Rocha, R., Smith, R.K. & Sutherland, W.J. (2020) Some Aspects of Control of Freshwater Invasive Species. Pages 555-87 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Control of Freshwater Invasive Species

This Action forms part of the Action Synopsis:

Control of Freshwater Invasive Species
Control of Freshwater Invasive Species

Control of Freshwater Invasive Species - Published 2017

Control of Freshwater Invasive Species Synopsis

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