CEDA (Catch and Effort Data Analysis) and LFDA (Length Frequency Distribution Analysis), are two pc-based software packages, designed for use by fishery officers in developing countries when carrying out fishery stock assessments, that were developed under the FMSP and first released in 1992. Both were developed for the then universally used MS-DOS operating system. More than 50 copies of the software packages were distributed to scientists and scientific organisations in developing countries during the year after their first release. Feedback from users of the original versions of the packages and experience gained during a follow-up adaptive project subsequently led to revisions of the software packages being made. Revised versions (CEDA Version 2.01 and LFDA version 4.01), which still used MS-DOS, but incorporated a Windows-like menu system, were released in 1995. By 1999, more than 150 copies of the revised packages were in use in developing countries worldwide. More recent feedback has been that the packages are getting harder to use with the modern Windows 95 or later operating systems, and the lack of a Windows-standard user-interface. Accordingly this project aimed to produce revised Windows versions of the two packages, which would then be able to be distributed to users via the Internet via the MRAG/FMSP website. Rewritten in Microsoft Visual Basic, the two software packages have standard Windows user interfaces and a very extensive context-sensitive on-line help systems. They also incorporate comprehensive tutorials illustrating the use of the packages, and separate guides on statistical issues and on use of population dynamics models. The LFDA packages allows users to estimate non-seasonal and seasonal growth curves from length frequency data using three alternative methods. Given these estimated growth curves, further analysis allows estimation of total mortality rates and estimation of age frequency distributions. The CEDA package allows users to fit a number of alternative population dynamics models to catch and effort data, thereby estimating stock sizes and important management quantities such as the maximum sustainable yield. The improved scientific advice available through the use of these packages will considerably enhance the likelihood of sustainable management of vital fishery resources, which in developing countries often represent major sources of animal protein, employment and income.
Fisheries Management Science Programme, Department for International Development, London, UK, 69 pp.