An example of the nutrient bypass can be found in the primary production in a tidal front. Takeoka et al. (1993a) found a prominent chlorophyll-a maximum in the subsurface of the tidal front formed in lyo-Nada around the Hayasui Strait, following observations conducted in July 1990. From analysis of the TS diagram, they inferred that the nutrients supporting the chlorophyll-a maximum were supplied not vertically from the lower layer but horizontally from the mixed region around the Hayasui Strait. This nutrient supply route can be regarded as transport through the nutrient bypass.