Fig 1.
Schematic view of salinity structure, oceanic circulation and the North Equatorial Current (NEC) bifurcation in the western North Pacific Ocean related to the presumed spawning location of A. japonica.
Blue spots in the inserted map show the catch sites of glass eel in Taiwan.
Table 1.
The details of sampling time, sampling location, climate status, sample size, the mean total length (TL) and the mean larval duration (LD) obtained from otolith daily increments analysis of A. japonica glass eel in the nine ENSO climate periods.
The mean TL was measured after 1+ months of preservation shrinkage.
Fig 2.
SEM photograph of the otolith of A. japonica glass eel.
Scale bar = 10μm. P: primodium; HC: hatching check; FFC: first feeding check; MC: metamorphosis check; E: edge. The definition of the onset in each edge was modified from Arai et al. [66].
Fig 3.
The regression analysis of the relationship between the mean larval duration and the mean total length (N = 182, r = 0.40, p < 0.05).
Fig 4.
Comparison of the (a) mean larval duration (day) and (b) mean total length (mm) of A. japonica glass eels among the nine selected years in Taiwan.
Numbers within bars indicated sample size. Bar charts with different letters above are significantly different (Duncan, p < 0.05) between different ENSO climate periods.
Fig 5.
Comparison of the mean total length (after preservation shrinkage) between different ENSO climate periods for A. japonica glass eels collected in Taiwan from 1984 to 2013.
(a) Stage VA (N = 5757); (b) Stage VB (N = 5011). Bar charts with different letters above are significantly different (Duncan, p < 0.05).
Fig 6.
Particle trajectories released at the spawning ground with different ENSO climate years.
Particles are released from (a) a fixed spawning ground of 14°N and (b) changing spawning grounds associated with latitude of the salinity front along 142°N. Spawning latitudes (SL) are the release points for simulation changed spawning grounds.
Fig 7.
Comparison of annual commercial catches of glass eel (tonnes) from East Asian countries (grey solid line, data from the Nihon Yoshoku Shimbun) and the percentage of released particles in the transport modelling study that entered the Kuroshio Current (black dashed line).
Fig 8.
Comparison of the mean drifting time among El Niño, normal and La Niña years.
Starting spawning area locations are: (a) a fixed spawning ground of 14°N and (b) at the latitude of the salinity front along the 142°E longitude.
Fig 9.
Comparison of the recruitment rate among El Niño, normal and La Niña years.
Starting spawning area locations are: (a) a fixed spawning ground of 14°N and (b) changing spawning grounds associated with latitude of salinity front along 142°E into Kuroshio Current (dark grey solid bar) and Mindanao Current (light grey slashed bar).