Brown and black bullheads: Application of a biocide

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

Study locations

Key messages

  • A study in the UK reported that use of a piscicide containing rotenone achieved eradication of black bullhead.
  • A study in the USA found that rotenone successfully eradicated black bullhead, but one of two ponds required two separate doses.


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 2014 at a fishery in Essex, UK (Environment Agency Invasive Species Action Group 2014) reported that use of a piscicide containing rotenone achieved eradication of black bullhead Ameiurus melas.  The piscicide was applied using a boat and a bank based application system. Dead fish were removed using nets.  During and after the operation, regular water samples were taken to monitor the level of rotenone.

    Study and other actions tested
  2. A study from 2001-2003 in two ponds in Illinois, USA (Towey 2007) found that rotenone successfully eradicated black bullhead Ameiurus melas, but one pond required two separate doses due to an incomplete initial kill.   Rotenone was applied in December 2001 using a motorised and hand-pumped sprayer at concentrations of 7 parts per million or 3.5 parts per million, with dose dependent on apparent fish susceptibility.  It was applied from several points along banks to ensure complete coverage.  A second application was applied in January 2003 as black bullhead catfish were not eliminated in 2001.  Ponds were sampled with wire minnow traps, D-frame nets and visual observations to ensure fish had been eliminated.

    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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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, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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