Concerns regarding food shortages are deepening due to global population growth and the economic expansion of emerging nations. To meet the demands of a growing global population, sustainable increases in food production are essential. One component of this is the fish supply, which comes from both wild catches and aquaculture. Global aquaculture production is projected to reach approximately 141 million tons in 2024, whereas the wild catch volume stands at 79 million tons. A major challenge facing aquaculture operators is the soaring cost of feed. The feed used in fish farming consists primarily of fish meal—made by crushing and pelletizing wild-caught fish like sardines—and soybean meal (the residue left after oil extraction). Feed costs account for 70% to 80% of total aquaculture operating expenses; for instance, raising a Pacific bluefin tuna to a weight of 30 kg requires 500 kg of feed. A common issue for operators is their reliance on imported fish meal, the global price of which is benchmarked against Peruvian production rates. In 2025, the price of high-grade Peruvian fish meal rose to $2,500 per ton, a 57% increase from the previous year.
Eels from Lake Hamana, for example, are renowned. The Lake Hamana Aquaculture Fishery Cooperative (based in Hamamatsu City) raises eels in the area surrounding the lake. Their production cost structure consists of 30% for feed, 30% for juvenile eels, and 40% for fuel and labor. Here, too, the purchase price of feed has risen by 20% year-on-year, placing a heavy financial burden on producers. Naturally, feed manufacturers are working to develop feeds that substitute fish meal with other ingredients less susceptible to market fluctuations. Insect-based protein is attracting particular attention in this context. Trials regarding the utilization of black soldier fly larvae in animal feed are currently underway. While the consumption of insects as food is still in the experimental stage in Japan, markets for such products are beginning to take shape in regions like the EU. The global market for insect protein—encompassing both insect-based foods and animal feed—was valued at 7 billion yen in fiscal year 2019 and is projected to reach $3.3 billion (450 billion yen) by 2027. In Europe, the market for insects is expanding beyond human consumption to include feed for livestock such as pigs and poultry.
In the EU, the sale of mealworms and migratory locusts as food products has been authorized. Mealworms are the larvae of darkling beetles and are known for feeding primarily on plants in the grass family. Meanwhile, in the United States, attention is focusing on insects such as black soldier flies and grasshoppers. It is hoped that the growth of the insect feed market will provide a solution to issues such as dwindling food resources and soaring prices. Insects have the characteristic of growing rapidly even with minimal feed; this efficiency has drawn attention to them as a potential source of fish feed. For instance, one company has developed fish feed using the common housefly. These flies are raised in factory-like facilities, similar to those used for plant cultivation. Mixing housefly larvae into aquaculture feed stimulates the fish’s appetite. Studies have also shown that when dried larvae are incorporated into feed at a rate of 5%, the farmed fish grow larger. The availability of affordable, nutritious insect-based feeds is expected to increase in the future.
