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3. Resonance with the external forcings from atmosphere 
3.1 Fishermen's knowledge of yellowtail fixed nets 
Yellowtail fixed net fishery on the Pacific-Coast deserves to be studied as a coastal and 
marine engineering of more than 400years in history. Aided with the knowledge base having been 
accumulated and sophisticated by the fishermen, we can uncover an air, sea and solid-earth 
interaction process, through which the coherence in the oceanic turbulence is excellently enhanced. 
Figure 5(a) shows a location map, in which rich fishing grounds on the Pacific-Coast are 
shaded (Uda 1941, 1983). The yellowtail fry transported north in summer by the Kuroshio, attain 
the growth in the highly productive Oyashio region, and migrates back south in winter. 
Comparing to the NOAA/AVHRR-based turbulence measurements shown in Figure 1, we 
find the southward migration route of grown up yellowtails lies inside the coastwise boundary layer, 
and the optimum fishing grounds are located just downstream of the Giant-Cusps. If the eddy 
shedding process at the Giant-Cusps was the geophysically dominant factor, we would rationally 
extract out its onsite evidences in the yellowtail fishery from the fishermen's knowledge base. 
3.2 "Kyuu-Chou".... rapid sea currents system induced by atmospheric storm 
The first person having remarked the geophysical significance of old fishermen's knowledge 
base on air and sea is Uda (1984), who left a large volume behind him titled "Forklore on Sea and 
Fish". From the viewpoint of oceanic turbulence, following descriptions on the "Kyuu-Chou" 
phenomenology is noticeable, which he abstracted from his hearings marked in Figure 5(a). 
Before or after a rainstorm, sea currents Shio is suddenly accelerated, a coastward current Komi- 
Shio are generated, schools of fish flocks ashore to lead to a big catch. Suddenly, rapid currents 
Kyuu-Chou occurs. A coastal-front, a boundary of watermasses, moves ashore. Sea states undergo a 
digital-like change in the direction and speed of Shio, water temperature, salinity, transparency etc. 
Schools of yellowtail or tuna approach to bring a big catch in the fixed nets. Water temperature often 
rises and falls in a catastrophic manner. We also call Shike-Shio the suddenly accelerated coastwise 
Nobori-Shio or offshore Kudari-Shio, which acts sometimes as the precursor of coming storm. 
Here, integrating with Figures 1 and 5(a), we reasonably judge the "Kyuu-Chou" phenomenology 
dominating the yellowtail fixed net fishery is physically reduced to the eddy shedding mechanism at 
the Giant-Cusps (Nishimura 1986). In Figure 5(c), the relationships are schematically shown. 
3.3 "Offlying fixed net".... outer edge of cyclonic eddy shed from Giant-Cusps 
Owing to the coherence in the eddy shedding process, the outer edge of cyclonic eddy 
forms a sharply defined boundary in the sea, across which physical quantities differ in a digital-like 
manner. The submarine barrier for the yellowtail migration stretches from the top of Giant-Cusp, 
which fishermen have appreciated calling "naturally installed offlying fence net" as follows. 
Synchronized with the arrival of atmospheric storms, the warm currents of Kuroshio and Tsushima- 
Current repeat hitting and leaving the coast, accompanying the movements of the coastal front and the 
approachings and leavings of yellowtails. They call the warm currents as "Oki-no-Kaki-Ami (offlying- 
fence-net)", which emerges naturally in harmony with the coastal topography of capes and reefs or of 
the coastward penetration of troughs. Driven by the Komi-Shio and the offlying-fence-net, schools of 
yellowtail intrude ashore. Along a white turbid line, they come into the mouth of the fixed net. The 
movement of the coastal front, offlying-fence-net against the yellowtails, tunes with the arrival of 
extratropical cyclones with a period of one week in winter. The yellowtail schools make excurtions 
inside the swirling currents called "Mai-Shio" or the stagnant seas downstream the capes. An undersea