Aquaculture in the Uwa Sea (2)
Two main factors make the Uwa Sea so suitable for fish farming.
Tailor-made topography
The Uwa Sea is distinguished by its sawtooth coastline, which began to take form during the most recent ice age. The sea level on the Uwa coast was up to 100 meters lower than it is now, leaving rivers to form deep valleys between the mountains and the ocean. When the ice age ended about 10,000 years ago and Earth’s atmosphere warmed again, the sea flowed into these valleys, turning them into the rocky inlets seen today. Their contours provide shelter from the wind and the ocean currents, making fish farming possible year-round.
Outstanding ocean currents
The Uwa Sea benefits from a constant inflow of oxygen-rich ocean water from the warm Bungo Channel between Kyushu and Shikoku. This mixes with warm water near the surface, brought in by the Kuroshio Current, and colder, nutrient-rich water deeper in the sea. This interplay of currents helps create ideal conditions for aquaculture.