Lorenzen Lab @ UF/IFAS

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Decision Support Tool for Fisheries Enhancements


EnhanceFish is a decision support tool for the quantitative assessment of aquaculture-based fisheries enhancements. It can be used for example to:

  • Evaluate whether releases of hatchery fish are likely to increase yields in a fishery for which enhancement has been proposed
  • Assess the likely impacts of releases on the wild stock of the target species (where one exists)
  • Analyse data from release experiments to estimate population parameters
  • Identify optimal release and harvesting regimes

The EnhanceFish toolkit has three components:

(1) The EnhanceFish tool, a software package. It contains a mathematical population model for enhanced fisheries and is used to carry out the quantitative analyses. Underlying EnhanceFish is an extended dynamic pool fisheries model with explicit representation of size-dependent mortality, density-dependence in the recruited phase, and differences in population parameters of wild and stocked population components. EnhanceFish provides empirical distributions of key parameters to allow prognostic evaluations, and conduct risk assessments. For more information on the scientific basis of EnhanceFish see the key reference below.

(2)  The EnhanceFish manual, which explains the principles underlying the EnhanceFish model and assessment methods. It also provides guidance on the practical use of the tool, including worked examples.

(3)  The EnhanceFish guide, which provides guidance on how to link the quantitative analyses supported by EnhanceFish to management and development of enhancements.

EnhanceFish is designed for use by fisheries and other natural resources professionals including for example government officers, NGO staff or development consultants. Use of EnhanceFish requires understanding of basic concepts of fisheries stock assessment. It does not require specialist knowledge or mathematical skills.

Enhance Fish Project Brief (0.2 MB PDF)

STREAM Enhance Fish Policy Brief (0.1 MB PDF)

EnhanceFish Beta release

The EnhanceFish toolkit is now publicly available as a Beta release for user testing. This means that you are welcome to test the software and associated documentation, but you should be aware that the software may have bugs and is not guaranteed to work correctly in all situations. Your feedback on any bugs or other problems you may encounter is important to us, as it will help us to improve the software for the first definitive release.



EnhanceFish Manual (4 MB PDF)

EnhanceFish Guide (1 MB PDF)

The following documents are frequently updated during Beta testing

EnhanceFish Known Problems (0.1 MB PDF)

EnhanceFish Frequently Asked Questions (0.1 MB PDF)

EnhanceFish support

Please report any problems you encounter using EnhanceFish Beta to our dedicated email help: [email protected]

Who is behind EnhanceFish ?

EnhanceFish has been developed by Kai Lorenzen and Paul Medley. Kai Lorenzen has carried out much of the research on population dynamics of enhancements that underlies EnhanceFish (see below for a key reference). Paul Medley has developed and programmed the EnhanceFish software.

The development of EnhanceFish has been supported by the UK Department for International Development (DFID), Fisheries Management Science Programme. For more information on other outputs of the DFID Fisheries Management Science Programme please visit www.fmsp.org.uk .

Key reference

More information on the scientific basis of EnhanceFish can be found in:

Lorenzen, K. (2005) Population dynamics and potential of fisheries stock enhancement: practical theory for assessment and policy analysis. Philosophical Transactions of the Royal Society of London, Series B 260: 171-189. PDF

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