© 2015 Elsevier Ltd. In this paper, we propose an automatic computation and data sharing scheme to support management system in coastal fishery using real-time fishery information through information and communication technology (ICT). In Japan, several species of fisheries commodity have not been specified in Total Allowable Catch policy, causing a lot of confusion on fishery cooperatives and fishermen on how to set the catch limit. To deal with the problem, in the previous study, we developed catchable stock index, a method to estimate a certain extent of resource via the swept area method. However, as the calculation of the index was computed on a GIS software manually, it was very time consuming, costly and unable to give an immediate evaluation of the fishing operation. This study aims to support management system in a coastal fishery through the development of automatic catchable stock index algorithm. In this study, ICT was utilized to obtain and transmit the real-time data sharing of fishery information as well as to distribute the computation results to the fishermen and fishery cooperative. The data used were vessels' trajectories and catch records, which included the start/end time and catch amount of each fishing operation. The catchable stock index was automatically computed in an originally developed cloud computing service. We have conducted the test run of the present method in sea cucumber dredge-net fishery on the coast of Rumoi City, Hokkaido, Japan. Data were collected from the entire vessels in Rumoi (16 vessels) during the 2012 and 2013 fishing seasons. The results were returned to the fishermen via the Internet each day during the fishing season, therefore, fishermen were able to immediately evaluate their catch. The estimated catchable stock index for the 2012 and 2013 seasons was 85.5tons and 92.3tons, respectively. By referring to the present system, fishermen voluntarily stopped the 2012 and 2013 fishing season several weeks earlier than their initial schedule to avoid overfishing. Moreover, in the previous study, the spacing of the grid has been decided empirically, but in this study, the adequate grid size could be evaluated due to the fast computation through ratio of the area of a grid cell to the total dredged area. In light of the evidence, the present automatic algorithm provided useful information for supporting the self-management of this coastal fishery.