Japan’s Nagasaki Prefecture experienced the worst case of red tide damage in the region’s history in early August, leading the prefectural governor to call on the country’s national government for additional aid to compensate affected aquaculture companies and research how to better anticipate red tide to prevent future damage.
The crisis stems back to late July, when people began to notice areas of dark brown water in Tachibana Bay along the coasts of Nagasaki, Isahaya, and Unzen. The affected water gradually spread, killing about 1.1 million tiger pufferfish, striped mackerel, and red sea bream farmed by 19 companies.
Nagasaki is the nation’s largest producing region of high-end, luxury fish products, and statistics from Japan’s Ministry of Agriculture, Forestry, and Fisheries show that the prefecture’s blowfish production accounts for about half of Japan’s total output. The loss to the affected species is likely to affect pricing and supply throughout the country.
Total damages from this instance of red tide amounted to an approximate JPY 1.3 billion (USD 8.8 million, EUR 8.2 million), making it the most expensive red tide damage ever recorded in Nagasaki.
The phytoplankton karenia mikimotoi, which thrives in rising seawater temperatures and in water with decreased levels of salinity, was the main culprit behind Nagasaki’s red tide. If the toxic phytoplankton exceeds 500 cells per milliliter of seawater, it destroys the gill tissue of fish on contact. Authorities confirmed concentrations of up to 3,400 cells per milliliter in the region.
In response to the disaster, Nagasaki Prefectural Governor Kengo Oishi, along with representatives from individual cities in the region and related fisheries cooperatives, visited national government offices to make requests regarding the damage.
“The red tide … caused the largest damage in the prefecture’s history, and there are concerns that the aquaculture production area will collapse and cause major damage to the local economy, so we request support from the national government,” the representatives stated in their request.
Specifically, they asked for …
Photo courtesy of Nagasaki Prefecture