Zooming into small-scale fishing patterns : The use of vessel monitoring by satellite in fisheries science

With the introduction of the European Vessel Monitoring by Satellite system (VMS), scientists could routinely access position data with an accuracy of around 100m. The introduction of VMS boosted the ability to explore the location of fishing activities (Murawski et al., 2005; Stelzenmuller et al., 2008; Fock, 2008), its relation to the habitat (Hiddink et al., 2006; Kaiser et al., 2006) and interaction with other fishing vessels (Poos and Rijnsdorp, 2007a) or users (Bastardie et al., 2015). My research aimed at expanding the use of VMS data to study the impact of fishing at small spatial scales (tens of meters) to be used in an international context taking account of the issues of confidentiality and transparency, allow for analyses to take place at small spatial and temporal scales, and gain a mechanistical understanding of how small scale fishing patterns arise. This to allow for predictions of fleet distribution to be made at small spatial scales.The PhD-thesis started with the development of transparent, generic and efficient methods to process fisheries data, both VMS and logbook data. Provided that in most countries, but in the EU specific, VMS and logbook reports contain very similar fields of information, standardized data templates were designed at which a suite of analyses tools could be applied to gain understanding in fisheries behaviour and the impact of fishing. An R software package VMStools was developed. This contains a suite of standardized functions to clean VMS and logbook data from evident incorrect entries, link datasets together in time and space and allowed for activity tracking of fishing vessels. The package shows how data from multiple countries can be combined to provide a more complete overview of fishing intensity. Among the routines available in the VMStools package is a tool to interpolate in between successive VMS observations to artificially reduce the interval time of VMS data and hereby reconstruct a trawling track. Although ther