Use satellite data to optimize the salmon release time -challenge a sustainable fishery project-

Speaking of the fishery industry in Hokkaido, salmon is salmon, but there is concern that the salmon returns to the river is decreasing due to global warming. In 2020, in 2020, the Cabinet Office applied for a "Sustainable Salmon Resource Production Support Project" in the Cabinet Office's "Advanced Sales Sensing Data Usage Demonstration Project" as a "sustainable salmon resource production support project". We demonstrated in Abashiri, Hokkaido. By using satellite data to release salmon fry to the sea, the decrease in fry is stopped and the sustainability of salmon fisheries is increased. Regarding this project, I asked the members Seiichi Saito, Professor Emeritus of Hokkaido University, Tatsuya Fujiwara of the Digital Hokkaido Study Group, Yasuyuki Miyakoshi of the Kitami Bureau and Product Business Association, and Takashi Hosokawa of Nitto Made Co., Ltd. 。

―― In fishing support using satellite data, you can think of an offshore fishing industry like a fishing ground forecast.How do you use satellite data in the coastal salmon aquaculture business?

Saito: Speaking of GIS use in the fishery business, fishing grounds are mainly used to increase catch efficiency, but they are also used to manage aquaculture.The coastal fisheries and aquaculture fisheries accounted for a large percentage of fishery, and the idea of expanding the applied destinations has come up with the idea of "can you use it more on the coast."In the past satellite sensors, it was difficult to observe the reflected light from bright land when shooting the coast, but recently the technology has progressed and the coastal area has been observed, and feasibility has increased.hey.In this project, salmon is targeted, but we believe that the range of use is wide because there is a possibility that it can be applied to flatfish released in the cultivated fisheries.

――What kind of cycle is salmon all year long?

Miyakoshi: Salmon is collected every fall and hatches around December to January.A small salmon, which has just been hatched, is called "shigyo", and immediately after birth, it nutrients from the eggs on the stomach of "Sainou", so it does not take nutrients from the outside.From around March to April, when it became a "fry", it was bred in the outdoor cubicated pond, and it was released in May.In nature, nearly 80 % of fry from other creatures from the eggs to go down to the sea, but if artificially hatched, about 80 % can survive.

If the grown fry is about 5 cm in length, the survival rate will be high after the release, but if the coastal seawater temperature is too cold, the residual rate will be low because the food will be poor.Until now, based on the boy observation information installed on the coast, the release time will start from the time when the water temperature on the sea surface exceeds 5 degrees, and the release will be completed around 10 to 11 degrees.I was.The fry that grows in the coastal area (generally 7cm long, 3g or more) will move offshore with a larger food.However, if the water temperature exceeds 13 degrees, it exceeds the water temperature area suitable for habitat, so small fry will have to leave the coast, so we will look at the timing so that the fry can eat the coastal bait well and grow.It is important to release it.

――What is the role of satellite data in this project?

Saito: It was adopted for the Cabinet Office's demonstration project in the summer of 2020, but the release of May was already over.For this reason, we have been working back in the past to develop the function of the water temperature prediction of the sea surface of the sea surface water temperature forecast, with satellite data analyzed by the Japan Meteorological Agency's coastal watery monitoring system.We prepared a function that can predict the water temperature three months ahead, and was released in May this year.

Miyakoshi: The "release timing record system" proposed in the demonstration business can predict the water temperature of the sea surface, so it can be used to determine the release time.If the water temperature is likely to rise quickly this year, it will be possible to adjust the release time, as the time spent on the coast will be reduced.

Saito: The salmon residual ratio is related to the time when it is just released and the winter season in the first year, but there are some parts that are not yet known what affects the mortality rate.。Therefore, there is an expectation that you can follow if you use the results of satellite data and numerical models.If you can continue for three years, you will be able to see what kind of environment the salmon, which came to the river for four years of salmon, was affected by the river.If the project is long -term, it is possible to have a sustainability, such as "it is likely to be caught as usual."

The salmon's life is about four years, so you need to continue your business for a long time.Currently, we are applying to JAXA so that data can be obtained as a project that can be continued for three years.

――What satellite data is used?

Saito: NASA's "TERRA" and "AQUA" satellites, NOAA satellites, JAXA's "Shizuku (GCOM-C)", etc.I am using it.In particular, "Shikisai" is very useful because the space resolution is 250m finely, and the coastal information can be seen in semi -real time about 6 hours later.In addition, the European Sentinel-3 has a spatial resolution of 300m and can check the water temperature and chlorophyll (chloroplast).This satellite achieves the top advanced open data in the world and is easy to use and popular.

At Hokkaido University, the Hakodate City International Fisheries and Ocean Research Center has a satellite data receiving station with an antenna with a diameter of 2.4 m on the roof, and immediately acquire the data of "Terra" and "AQUA" and use it immediately.I can do it.The data of "Risesat" launched jointly with Tohoku University in 2019 is also received, and it is also used to drop data when passing over Hakodate.This fall, we use this satellite data for observing red tide in the eastern road.

――How do fishermen, a user, use the water temperature forecast system on the sea surface?What is the actual feel?

Saito: When you log in on the web, you can see the forecast of water temperature and salt concentration based on past satellite data and numerical forecast models.

Miyakoshi: I used it for the first time this year as a user, but it will be helpful because the prediction of the water temperature rising one week ahead can be seen in the image.You can see not only the water temperature on the surface but also the vertical salt cross section.The concentration of salt reflects the distribution of the sea current called Soya warm current coming from the north, which is very helpful because it helps to grasp the places where salmon food is used.

――Isn't there any system that predicts the coastal water temperature?

Saito: There are fisheries test sites in various parts of Hokkaido, but there was no unified and giving predicted values.I think there are other systems that understand the current situation, not forecast, like Aomori Prefecture.Prototype Web GIS is a system that allows you to obtain predictive data from the Japan Meteorological Agency's coastal coastal coastal monitoring system, and visualize predictive distribution of water temperature, salt, and sea current.The other is that Kyushu University has developed a numerical prediction model called "Sea Status Prediction (DREAMS) near Japan" and can be seen on the web.In Japan, this is the only two in Japan that can provide a surface -like coastal water temperature map in conjunction with our system?

――What is the division of roles of project members in system development?

Saito: The project is involved in four organizations, and the role of the summary of the promoter is the Digital Hokkaido Study Group, the development of Nitto GIS tools as information providers for fisheries applied, green & life innovation, and analysis of data.And the creation of information is the role of Hokkaido University.

Fujiwara: The Digital Hokkaido Study Group was launched in 1991 as a voluntary organization and was launched in 2008 as an NPO.For "Educational Research Institute," "Administrative Organization," "Private Businesses," and "General Citizens and others" in HokkaidoThe purpose is to contribute to the development of the economy and society by conducting a business related to the development of spatial information infrastructure.Recently, one of the research themes is to use GIS, such as how to use the high -precision position of the quasi -top satellite "Michibiki" in smart agriculture and construction industry.He plays a role in connecting universities, research institutions, and companies, including satellites, open data of Hokkaido image samples, archive and utilization of data.

Saito: I was originally a ocean GIS researcher and promoted remote sensing and GIS promotion and data utilization at Hokkaido University and Digital Hokkaido Study Group.The most advanced use of marine GIS is the fishery industry.Although satellite data does not lead to use just by "seeing data", GIS is very effective as an expressive and visualization tool.It can also be used for fishing ground predictions and can be used by private companies.Currently, the form of Web GIS that can be used in the cloud is becoming mainstream, and this tool is also a prototype form.

The Kitami jurisdiction and the proliferation business association, the user of the system, are in charge of the data evaluation.In addition, we have shared and analyzed data in the past 20 years, such as the number of years and how many months, and how many years you have taken, how many years you have taken.

Hosokawa: We, fishing network makers, are participating in commercialization in anticipation of future sustainability of the fishery industry.There is a change in which fish cannot be removed not only in Kitami but also in other areas, and as a result, the whole, such as distribution processing, to consumer and fishing network manufacturing businesses.If the salmon resources were not sustainable, the fixed net fishery would not continue.

――The business operator involved in salmon fisheries plays a central role as a user, but how did you build a relationship of trust in sharing subtophy data?

Saito: In general, many fishermen do not want to disclose their own data, especially in the Okinai fishery, "how much fish they took."Mr. Miyakoshi of the Kitami jurisdiction and the proliferation business association and I have a long -standing relationship of trust, so I was able to share the data and analyze it.I think that trust relationship is indispensable in creating an application.

Miyakoshi: I have been in Hokkaido, and I have been in the internal water production test site for about 30 years, and I used satellite data in the Fisheries business in the Environmental Research Center.At that time, Mr. Saito began to cooperate as a satellite remote sensing expert.

Saito: It was around 2004 that I created the "Tredas" fisheries using satellite data, and at that time, the use of satellite data in the fisheries has not yet progressed.At that time, a lot of salmon was returned, and the effects of global warming were not as strong as it is now, but there were already concerns.For this reason, I had been thinking about applying for water temperature forecasts during the release time.

――You've been predicted that the environment can not be removed due to changes in the environment for nearly 15 years ago.After actually analyzing satellite data, what is the change in the environment surrounding salmon and the sea?

Saito: From the data for about 10 years, the day when the water temperature is 13 degrees tends to be a few days earlier, and in the area, the south area near Abashiri is stronger than the north.Isn't it about a week early?Although it does not reach long -term forecasts, the trend is always monitoring.

We are also trying to observe the red tide along the eastern coast of Hokkaido, which has been a problem since the fall of this year.From the point of Kamchukka, the poisonous whirlpool -haired algae (Uzuben is already so much) is observed with the OOC, an ocean observation camera installed in the small satellite "Risesat" we launched.It is predicted that the whirlpool algae have rides on the cold ninstto from the north, but in the current satellite sensor, the poisonous whirlpool algae and the harmless diatomy ages that feed on scallops.The challenge is that it is difficult to classify and observe.

――There is still an issue in the technical aspects of satellites.What kind of development will be expected to have satellite remote sensing supporting fishery in the future?

Saito: The request for the next -generation satellites discussed in the Remote Sensing community is desirable to improve the time resolution (observation frequency) as a sunflower and the space resolution.The Constellation type, which uses multiple small satellites, can increase the observation frequency.

In addition, in terms of observation equipment, I think that it is necessary to respond to "chlorophyll-A concentration" that can observe red tide.JAXA's "Shikisai" is observing "chlorophyll -A concentration", but it is presumed that "offshore is diatomy".In the future, it is expected that if a small satellite is equipped with a hyper -spectrum sensor, algae that cause red tide will be distinguished.The sea is dark and has a low reflectance, so you need a high -sensitivity hyper -spectra sensor.It would be nice if it could be realized with a small satellite Constellation that can be observed in a dedicated satellite for observing the sea.

* This article is the Space Business Information Portal Site S-NET "Use satellite data to optimize the salmon release time-Challenge a sustainable fishery project-Hokkaido University / Digital Hokkaido Study Group / Kitami Bureau Inside the BreastIt is published in the Business Association / Nitto Net Network Co., Ltd.

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