Driven by the need to replace the labor and know-how of their country's aging population, innovative Japanese companies are leading the way when it comes to developing new technologies for aquaculture.
Robotics and information and communication technology (ICT) are playing a bigger role in aquaculture in Japan, which is faced with an aging fisheries workforce. Robots are feeding salmon on farms, and sensors on buoys are gathering and transmitting data in real-time to assist oyster and seaweed cultivation.
Nippon Suisan Kaisha has installed a robotic feeder at pens for silver salmon in the Sea of Japan, off the coast of Tottori Prefecture. It supplies feed on a preset schedule, but it is not a mere timed feeder; it also contains a feed-demand sensor that detects fish strikes on fake feed. The amount of feed dispensed by the automatic feeder is adjusted based on these detection results, improving efficiency and lowering water pollution by excess feed. The company was granted a patent for its feeding method and system for farmed fish last year.
Meanwhile, Tokyo-based mobile phone company DoCoMo has been trying to address the problem of Japan’s aging population with technology.
High water temperatures result in oyster spat mortality. Water temperature management is very important in oyster farming, but on-site patrols to measure the temperature were impractical. In past years, experienced oyster farmers could estimate water temperature from experience. As these old hands retire, their experience will be replaced with objective data analysis.
In the Tohoku area, DoCoMo has developed and implemented a water temperature observation ICT buoy. In a demonstration project started in 2014, the buoys take hourly readings of seawater temperature in the aquaculture area at a depth of 1.5 meters. After successfully proving itself in trials, the module was commercialized in March 2016.
DoCoMo has also developed an app for smartphones and tablets that shows recorded water temperature readings, updated every hour, as well as charts of historical data and comparisons between years. In the future, wind direction and speed, wave height, and water quality state (such as saturation quantities of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen) may be measured by the sensors.
Buoys are also a research subject of the National Institute of Information and Communications Technology (NICT), Japan’s only agency specializing in the field of information and communications technology.
This organization has been working on extending battery life of ICT buoys, since it is impractical to change batteries on the sea frequently. Its pilot project, on a mozuku seaweed operation in Okinawa, not only measured water temperature, but also salinity.
To conserve battery power, the sensors remain in sleep mode most of the time. They turn on only a few seconds per hour, to pick up a sensor reading. There are three buoys in the system at differing distances from shore and in different depths of water. The first and last buoys contain sensors, while the middle buoy is a relay, allowing the data to be gathered by short low-power hops to a single buoy for transmission to a base tower on land. The data is stored in the cloud and is available online.
The device uses the Wi-SUN radio device, based on a low-power radio protocol. This type of low-power local broadcasting will find use outside of fisheries in smart home electrical meters, appliances, and home electricity management systems.
