Fish species composition was observed by using Remotely Operated Vehicle （ROV）and time lapse camera around an anchored fish aggregating device （aFAD）in Goto Islands, Nagasaki in summer 2018. A total of 10 families and 15 species were observed by both ROV and time lapse camera. The most frequently observed fish was largescale blackfish Girella punctata recorded by both techniques. More families and species were observed by the time lapse camera as compared to the ROV. However, Shannon’s diversity index was low for the time lapse camera compared to the ROV. Bray-Curtis similarity index between the ROV and the time lapse camera was 0.95 suggesting that the observation between the 2 techniques was different. This could have been attributed by the difference in mobility by both techniques, temporal and spatial distribution of aggregated fish around the aFAD. Therefore, researchers investigating artificial fish habitats including aFADs should understand such potential differences among visual observation techniques and utilize the advantages and disadvantages for better understanding of fish fauna around the habitats.

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Stereo vision systems have been employed for monitoring the size of fish reared in aquaculture production facilities. A time-synchronized method using audio records is used to synchronize stereo cameras consisting of two stand-alone underwater cameras. In this study, a time-synchronized video analysis was conducted on objects moving on an elliptical orbit rail to assess the influence of frame rate and shutter speed on the measurement accuracy of a stereo camera. A coverage rate was defined for the reconstructed moving object in the stereo images to assess the accuracy of measurement. The coverage increased at high frame rates and at high shutter speeds under a high frame rate. Although the shutter speed affects illuminance in the experimental space, a higher frame rate should be set when using a stereo camera. This study shows that frame rate is the most important factor when measuring a 3D image using a stereo camera, provided a suitable shutter speed is used.

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In aquaculture，the net is fixed underwater for a long term. Periphytons are easy to attach to the net，therefore it is necessary to clean the net regularly. In addition，the net may be broken by the rapid current or marine animals，it is necessary to repair the net for prevent fishes from escaping to outside of the net. But huge labor is demanded to clean or repair after lifting up the net. When divers work underwater，the work is often difficult under the influence that high water pressure and low water temperature. Therefore，underwater robot is useful to work underwater instead of divers under the severe situation. As the pre-stage，this paper reports on the underwater mobile mechanism for the robot of ROV （Remotely Operated Vehicle）type to use at the net.

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Fisheries facilities were severely damaged by the Great East Japan Earthquake that occurred on March 11, 2011. Recovery and reconstruction of fishery facilities have been actively promoted until now after the earthquake, but recovery and reconstruction of the fishery processing industry is significantly delayed compared to other industries. 　　In this paper, based on the census of manufactures before and after the earthquake, we examined the situation of restoration and reconstruction of the fishery processing industry. The items to be compared are the value of manufactured goods shipped by industry and by company size, and labor productivity, etc. Based on the examination results, we grasped the process of restoration and reconstruction of the fishery processing industry, considered its characteristics and issues.

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As the international demand for marine products increases, exports expand, and concerns about the management of resources and sustainable fisheries grow, it becomes increasingly essential to improve hygiene and quality management in fishing ports, as well as the efficiency of and traceability of market transactions. While fishing ports and markets go about installing facilities and equipment for hygiene management in a systematic manner, however, it is true that, aside from those in a small number of locations, transaction procedures in most fish markets remain utterly dependent on handwritten paper forms such as order slips. Japan’s population is graying and dwindling and fishing communities are faced with their rapid declining and aging population. Therefore, it is necessary to promote the computerization for the operations of fish markets, particularly for the handling of market transactions. 　　This will be beneficial for reducing time and labor, as well as improving traceability and resource management. This report provides the results of a quantitative analysis of the benefits of the computerization for the operations of the Ofunato fish market where the market transactions were monitored with Internet Protocol （IP）cameras and visual observations were also made during the peak fishing season in October 2018. 　　The number of the assigned personnel has slightly decreased from 22 to 20 persons, and the total scheduled work time has shrunk by 12% from 213 to 188 hours. The time spent in actual labor has fallen from 213 to 158 hours, which is a 26% decrease. Bidding time （or lead time）has been shortened by about half an hour. The savings in the buyers’time spent in the main market building for the purchase of fish have been estimated at between 24 and 30 minutes （20–25%）. We anticipate carrying out similar analyses in other advanced markets in the future and also look forward to improving the accuracy of the aforementioned analytical procedures.

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Currently, coastal protection facility inspection checks are being carried out by means of visual observation and measurement both on the land and from the sea, and the labor-saving technologies and practices have become challenging issues. This study considers the practical application of a new method of inspection that combines aerial photography by UAV with 3-dimensional image analysis using SfM as a means of replacing conventional manpower. The results of the study verify that, with the exception of the detailed measurements made in secondary inspections, it is possible using this method to ascertain changes in all inspection items, including cracking, flaking and damage of structures, as well as changes in the status of the embankment as a whole, such as subsidence, collapse and displacement.

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