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.
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.
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.
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.
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.