Crassula helmsii: Use dyes to reduce light levels

How is the evidence assessed?
  • Effectiveness
    0%
  • Certainty
    53%
  • Harms
    not assessed

Source countries

Key messages

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 replicated, controlled study in 2011-2014 at waterbodies in the New Forest, UK (Ewald 2014) reported that treatment with aquatic dye, along with other treatments at some sites, did not reduce cover of C. helmsii, although no statistical tests were carried out. Average coverage of C. helmsii was 72% before and 75% at the end of the dye treatment, compared to 63% and 70% respectively at control sites. The study also showed that coverage of native plant species fell from 17% to 11% at treatment sites and from 17% to 14% at control sites over the trial period. Several other treatments (mechanical removal, herbicide, hot foam) were also used at some sites during this trial. A combination of Dyofix blue and black pond dyes were applied to six ponds on 5-6 occasions between August 2011 and December 2013. C. helmsii coverage was assessed in five random 0.25 m2 quadrats within each treatment area in winter and summer from 2011-2014, and also in seven control ponds.

    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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