a larval phase), transporting larvae from southerly coral reefs to downstream reefs along the Ryukyu Arc. Squid Western boundary currents are used by certain species of squid for rapid and easy transport, allowing mature squid to travel with minimum energy expenditure to exploit rich northern feeding grounds, while eggs and larvae develop in the warm current waters during winter. The Japanese flying squid (Todarodes pacificus), for example, has three populations that breed in winter, summer, and autumn. The winter spawning group is associated with the Kuroshio Current, because following spawning events in January to April in the East China Sea the larvae and juveniles travel north with the Kuroshio Current. They are turned inshore and are caught between the islands of Honshu and Hokkaido during the summer. The summer spawning is in another part of the East China Sea, from which the larvae are entrained into the Tsushima current that flows north between the islands of Japan and the mainland. Afterward, the current meets a southward flowing cold coastal current, the Liman Current. The group of squid spawned in the summer are traditionally found around the boundary between the two currents, sustaining rich fisheries. In fact, studies have reported that annual catches in Japan have gradually increased since the late 1980s and it has been proposed that changing environmental conditions have caused the autumn and winter spawning areas in the Tsushima Strait and near the Goto Islands to overlap. In addition, winter spawning sites over the continental shelf and slope in the East China Sea are expanding. Vertebrates Fish The Kuroshio Current is home to thousands of fish species occupying nutrient rich and diverse waters in this region. This expansive biomass is influenced by elevated rates of primary production leading to large biomass in the lower trophic levels, facilitated by warmer local oceanic and atmospheric conditions. Resident fish of this area include reef fish like rabbitfish and parrotfish, pelagic fishes such as sardines, anchovies, mackerel, and sailfish, and higher trophic predators such as sharks. Fisheries have a strong presence in this area and depend strongly on the changing oceanic conditions, largely dependent on the Kuroshio Current. To the north, the Oyashio Current contains subarctic water that is much colder and fresher than the resident water east of Honshu, and the intersection of these two currents is called the Kuroshio-Oyashio region. Here, local oceanographic conditions vary through the year and determine