Asian clams: Use gas-impermeable barriers

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms
    not assessed

Study locations

Key messages

  • A controlled study in North America found that placing gas-impermeable barriers across the bottom of the lake (several small fabric covers or one large cover) significantly reduced the abundance of Asian clams.


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 controlled, replicated study conducted in 2009-2011 in Lake Tahoe, North America (Wittmann et al. 2012) found that gas-impermeable fabric laid across the lake bottom killed 98-100% of Asian clams Corbicula fluminea after 30-120 days. During one trial all clams were killed after one month, compared to only 3% in control plots without fabric. During the second trial the abundance of Asian clams after 120 days under gas-impermeable fabric was 98% lower than clam abundance in control plots. One year after the barrier was removed from this second trial, clam abundance was still 90% lower compared to control plots. Mortality was caused by a reduction in dissolved oxygen concentrations, which dropped to zero after 72 hours during the first trial and after eight days in the second trial.  In 2009, six plastic (ethylene propylene diene monomer) barriers (9m2; 1 mm thick) were placed by scuba divers on the lake bottom at 5 m water depth and left in place for 4-56 days. In 2010-2011 a plastic barrier (1,950m2; 1 mm thick) was placed by scuba divers on the lake bottom at 5m depth and left for 120 days. The survival of clams underneath the fabric test sites and in control plots was monitored.

    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

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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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