image: Associate Professor Toshimasa Yamamoto of Okayama University of Science holds a hybrid grouper cultivated through land-based aquaculture in Mongolia, which grew to approximately 8 kilograms in three years. Photo taken in September 2022.
Credit: Okayama University of Science
In the English listening section of The Common Test for University Admissions, Japan’s nationwide standardized university entrance examination, administered on January 17, a form of land-based aquaculture using “the new type of water” was featured.
In the exam, this water was described as being made by adding selected minerals found in seawater to freshwater, resulting in a mixture that is lower in salt and mineral content than seawater. The passage highlighted several characteristics, including the ability to raise marine fish in landlocked countries, faster growth rates, and greater resistance to disease. These characteristics correspond closely to The Third Water, an innovative water technology developed by Okayama University of Science and currently used for land-based aquaculture both in Japan and abroad.
In Question 5 of the English listening test, the opening passage —titled “A New Way of Fish Farming” —introduced this water as “the new type of water.” The passage explained that this aquaculture method is one of the important means of addressing global food shortages and referred to the farming of marine fish in the landlocked country of Mongolia.
The passage further noted that, compared with wild fish, farmed fish grow faster and have a lower incidence of fatal diseases, and stated that these factors contribute to commercial success. In addition, it explained that the water can be reused not only for fish farming but also for the cultivation of salt-tolerant plants such as tomatoes.
At Okayama University of Science, research is also being conducted on aquaponics, a circular agricultural system that utilizes The Third Water. With the university’s cooperation, Higashi-Okayama Kogyo High School, a technical high school operated by Okayama Prefecture, is experimenting with aquaponics that combines the farming of giant grouper (Tamakai) with the
hydroponic cultivation of banana plants and other crops.
The exam questions focused primarily on the characteristics of “the new type of water.” In the final question, test-takers were asked to select the statement that fish farming with the new water could increase fish and seafood consumption even in countries like Luxembourg.