Water primrose: Physical removal

How is the evidence assessed?
  • Effectiveness
    30%
  • Certainty
    50%
  • Harms
    not assessed

Source countries

Key messages

  • A study in the USA found that hand pulling and raking water primrose failed to reduce its abundance, whereas hand-pulling from the margins of a pond eradicated a smaller population of water primrose.

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 study in 2005 in a managed wetland in the Laguna de Santa Rosa, California, USA (Sears et al. 2006) found that hand pulling and raking water primrose Ludwigia sp. failed to reduce its abundance, whereas hand-pulling from the margins of a pond in the Laguna Wetland Preserve Sebastopol successfully eradicated a smaller population of water primrose.  Attempts to reduce the coverage of primrose in the Laguna de Santa Rosa, California, were wholly unsuccessful and by the end of the season water primrose covered 100% of the pond.  Hand pulling and raking were carried out for 2-6 person hours/week.  Workers in the Laguna Wetland Preserve at Sebastopol spent approximately 150 person hours of effort hand-pulling water primrose from pond margins.

    Study and other actions tested
Please cite as:

Aldridge, D., Ockendon, N., Rocha, R., Smith, R.K. & Sutherland, W.J. (2019) Some aspects of control of freshwater invasive species. Pages 569-602 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. 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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What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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