RIASSUNTO
Vessel Monitoring Systems (VMS) provide trajectory data of fishing vessels to discover the spatial-temporal pattern of fishing activities. Although previous researches exhibit the fishing resource distribution in space and time, the information on vessel sailing activities traveling from one fishing region to another are lost. These kinds of activities indicate the link relationships among fishing regions. Moreover, the pattern accuracy depends on the precision of fishing activity recognition, which cannot be testified by the VMS data itself. The major challenge to find precise fishing regions and sailing roads linking the regions is the chicken-and-egg conundrum. Because there are no pre-existed routes in oceans like on land to define the blocks. This paper proposes an iterative style scheme to calculate the fishing regions and sailing roads between regions simultaneously, which applies the sailing segments between the coarse recognized fishing activities. We takes the VMS traces of 34 otter trawls in the East China Sea as the research object ranging from April 1st, 2014 to June 30th, 2016. The results are calculated with the time period of one quarter, which not only indicate the precise separation of fishing regions, but also reveal the link relationships between regions. This leads to the precise fishing region and roads recognitions, which will help the fishery researchers for further analysis on VMS trace data.