Effect of ENSO events on larval and juvenile duration and transport of Japanese eel (Anguilla japonica)

PLoS One. 2018 Apr 10;13(4):e0195544. doi: 10.1371/journal.pone.0195544. eCollection 2018.

Abstract

Spawning ground of Japanese eel (Anguilla japonica) is located near the West Mariana Ridge seamount. The species travels through the North Equatorial Current (NEC) and then enters the Kuroshio Current (KC) on the migration toward East Asian growth habitats. Therefore, El Niño-Southern Oscillation (ENSO) events serve as the potentially important drivers of interannual variability across the equatorial Pacific. Because the NEC bifurcation and salinity profiles are related to ENSO events, we investigated the influence of locations of the NEC bifurcation and salinity front on the success of larval entry to the KC by numerically modeling particle transport in ocean currents from 1972 to 2013 and possible effects on the size of glass eels at continental recruitment and, via otolithometry on the duration of larval migration. Circulation and hydrography used for particle tracking were obtained from the results of the Model for Interdisciplinary Research on Climate (MIROC) high-resolution forecasting experiment. Our results demonstrated that during El Niño years, (1) the southward movement of the salinity front might cause the larvae to experience slower currents and (2) the northward movement of the NEC bifurcation might broaden the separation between their spawning ground and NEC bifurcation, thus prolonging the time needed for the larvae to enter the KC from their spawning ground, because of which the duration of entrainment in the water column and body size increase when eels reach estuarine waters. In addition, this might cause more water to flow into the Mindanao Current (MC), leading to a decline in the rate at which larvae get entrained into the KC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anguilla*
  • Animals
  • El Nino-Southern Oscillation*
  • Larva*
  • Models, Statistical
  • Water Movements

Associated data

  • figshare/2b08cd5251c4455a2e20

Grant support

This research was supported by Grant-in-Aid for Scientific Research (JSPS KAKENHI Grant Numbers JP16H04734) from the Japan Society for the Promotion of Science (JSPS) to SK. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.