Implement multi-year or long-term management strategies

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

Key messages

  • One study examined the effects of implementing multi-year or long-term management strategies on marine fish populations. The study was worldwide.






  • Stock status (1 study): One worldwide study found that commercial fisheries with multi-year or long-term management plans in place, among other management and governance strategies, had stocks that were more likely to be sustainable and less likely to be in decline compared to fisheries typically without long-term objectives.

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 site comparison study in 2005–2012 of 11 marine areas worldwide (Bundy et al. 2017) found that commercial fisheries managed with multi-year or long-term management plans in place, in addition to a range of other management measures and governance (those with higher “management effectiveness” and quality of governance) had better overall ecological status (sustainable stocks, non-declining exploited species) compared to those typically without long-term objectives (and with “lower effectiveness” and governance). For 11 ecosystems, the ecological status, defined by indicators for sustainable stocks, non-declining exploited species and ecosystem status (health), was greater in ecosystems where management and governance measures for fish stocks were ranked as being high, for example where long-term management plans were in place, in addition to biological reference points being used in assessments, illegal and unreported fishing addressed, and with greater harvesting sector participation, compared with those with lower rankings (data reported as model outputs/statistical results). Data were collected for a total of 27 global ecosystems as part of a large research programme (“IndiSeas” – Indicators for the Seas). Fisheries management effectiveness and governance quality rankings were derived from survey questionnaires completed by 61 experts (fisheries managers and scientists involved in management advice in each of the ecosystems), covering aspects such as management measures/plans, level of fisheries assessments and participation of the harvesting sector. Survey results were then analysed against eight ecological (derived from other IndiSeas outputs) and socio-economic indicators for 11 of the ecosystems, derived (see paper for details of ecosystems, management effectiveness and governance indicators, survey questions, data sources and full methods).

    Study and other actions tested
Please cite as:

Taylor, N., Clarke, L.J., Alliji, K., Barrett, C., McIntyre, R., Smith, R.K., and Sutherland, W.J. (2021) Marine Fish Conservation: Global Evidence for the Effects of Selected Interventions. Synopses of Conservation Evidence Series. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Marine Fish Conservation

This Action forms part of the Action Synopsis:

Marine Fish Conservation
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