Title: Feasibility of using the vessel monitoring system in Sierra Leone to monitor and assess the industrial fishery.

Final project
Year of publication:
Place of publication:
Number of pages:


In Sierra Leone Vessel Monitoring System (VMS) is only used to monitor in real time as a role in the enforcement of fishery regulations. The paper looks at the possibility of using this system to assess the industrial fisheries of Sierra Leone in evaluating the quality of VMS data collected to ascertain: 1. whether it can be combined with logbook data for mapping fishing effort by vessel, 2. describe the spatial distribution of fishing effort, and 3. map the catch of the main target species. The R programming language was used to analyse VMS data provided by AST marine via the Ministry of Fisheries and Marine Resources (MFMR) and the logbook data from the Sierra Leone Industrial Fisheries database (SLIFDAS). This paper represents the first attempt to link VMS and logbook data to evaluate the potential to map fishing effort and catch. In this study the evaluation of the level of coincidence between VMS data classified as fishing, using speed thresholds for individual vessels and the presence of entries in the logbook database gives a mixed result. On one hand, it is evident that there is a fair amount of overlap between the VMS and logbook data, meaning that for a vessel there is at least one VMS record classified as fishing in dates in which fishing activity was reported in the logbooks, with some vessels having a relatively high degree of coincidence through the entire period. On the other hand, there are several problematic patterns, vessels reporting fishing activities in the period June 2017 to May 2018, for which there is no VMS data classified as fishing. The VMS classified as fishing was used to map the relative fishing effort by category and those of the logbook were used to map the relative catch. VMS data have the potential to improve fisheries management and serve as a baseline to validate logbook positions and provide estimate of fishing effort by mapping of the catch. Lack of clarity in VMS coverage and inconsistencies in the logbook database introduce difficulties in combing the VMS and logbook data leading to limiting data sets. Personnel should be trained in modern methods of data management and analysis.

Read More



Documents and links