We are pleased to offer the latest versions of five fisheries assessment software packages for downloading free from this website; Length Frequency Distribution Analysis (LFDA), Catch Effort Data Analysis (CEDA), Yield, ParFish and EnhanceFish. All five packages were developed by MRAG Ltd. as part of the Fisheries Management Science Programme for the UK Department for International Development. We kindly ask you to register to download the some of the software so we are able to monitor the number of people who have been able to make use of the products.
LFDA Version 5.0The Length Frequency Distribution Analysis (LFDA) package is a PC-based computer package for estimating growth parameters and mortality rates from fish length frequency distributions. Version 5.0 of LFDA includes methods for estimating the parameters of both non-seasonal and seasonal versions of the von Bertalanffy growth curve. It includes three methods for estimating growth parameters. These are Shepherd's Length Composition Analysis (SLCA) method, the projection matrix (PROJMAT) method, and a version of the Elefan method. A facility is provided that allows conversion of length frequencies to age frequencies using the estimated growth curves. In addition to methods for estimating growth parameters, the package also includes three methods for estimating the total mortality rate Z, given estimates of the von Bertalanffy parameters. A function allowing simulation of length frequency data under a variety of assumptions is also included. As with previous versions of LFDA, the package includes a comprehenive context-sensitive Help system and a detailed example analysis.
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CEDA Version 3.0
The Catch Effort Data Analysis package (CEDA) is a PC-based software package for analysing catch, effort and abundance index data. Version 3.0 allows calculation of estimates of current and unexploited stock sizes, catchability and associated population dynamics parameters. Both depletion and several types of stock production (biomass dynamic) models can be fitted, using one of three different assumptions about the distribution of residuals. Both point estimates and bootstrap confidence intervals for the estimated parameters can be calculated. CEDA also includes the facility to do projections of stock size into the future under various scenarios of catch or effort levels, so that different management strategies can be investigated. Output is presented both graphically and textually, and can be printed or saved to disk for further use. As with previous versions of CEDA, the package includes a comprehensive context-sensitive Help system and a detailed example analysis.
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Yield Version 1.0
Yield Version 1.0 is a program for calculating fishery yields and stock biomasses, on an absolute or per-recruit basis, and for calculating biological reference points associated with these. On starting the program, users are asked to enter values of biological parameters (e.g. growth, mortality, age at maturity and stock-recruitment relationship) and fishery parameters (e.g. length at first capture, fishing season). For each parameter, either a single value can be entered, or a probability distribution can be specified to allow for uncertainty. When calculating yields and yields per recruit, the program takes explicit account of specified parameter uncertainties, presenting results in terms of histograms. Transient projection and reference point calculations can also be made, once the extent of stochastic recruitment variability has been specified. As with CEDA and LFDA, the package includes a comprehensive context-sensitive Help system and a detailed example analysis.
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ParFish Version 2.0
Participatory Fisheries Stock Assessment (ParFish) Software is a PC-based software package that uses Bayesian Statistics and Decision Theory to assess the state of a fishery stock and estimate limit and target control levels. The software supports the overall approach which is described in the accompanying ParFish Guidelines. The guidelines provide an overview of all six steps in the approach including: i) understanding the context; ii) engaging stakeholders; iii) undertaking the stock assessment; iv) interpreting the results and giving feedback; v) initiating management planning and vi) evaluating the process.
The ParFish software is currently based on the logistical biomass growth model and requires information on four parameters: Current Biomass, Unexploited Biomass, Catchabilty and Growth rate. Interview data from fishers are used to construct 'priors' for the model parameters which can be combined with other available information to provide best estimates. This information is then used, together with preference data from fishermen, to calculate the current stock level and the control levels that will provide the most preferred catch rates for fishers. The programme takes explicit account of uncertainty in the data, presenting results as probability density functions (with accompanying mean, median, mode and confidence intervals). The Software is accompanied by a manual which gives step-by-step guidance on inputting data and running the analysis. There area also additional reference sheets which assist with the interviews and other data collection methods.
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The EnhanceFish Tool is a PC-based software package for the analysis and planning of aquaculture-based fisheries enhancements. At the heart of the EnhanceFish Tool is a population dynamics model for enhanced fisheries. EnhanceFish can be used to assess whether stocking of hatchery fish are likely to improve productivity and economic performance of a particular fishery, and to identify optimal stocking and harvesting strategies. EnhanceFish also models impacts of enhancement on the wild stock of the target species, thus supporting ecological risk assessment of enhancements. The EnhanceFish Tool is accompanied by a manual which provides detailed guidance on running the software and conducting analyses. Complementing the EnhanceFish Tool is a recommended approach for integrated interdisciplinary analysis of enhancement systems, outlined in the EnhanceFish Guide. EnhanceFish was developed by Imperial College London as part of the DFID Fisheries Management Science Programme, and is supported through a discussion group and online help.
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For further information, downloads and support please visit the EnhanceFish Homepage.