Climate variation and anchovy recruitment in the California Current: a cause-and-effect analysis of an end-to-end model simulation

TY - JOUR

T1 - Climate variation and anchovy recruitment in the California Current

T2 - a cause-and-effect analysis of an end-to-end model simulation

AU - Politikos, D. V.

AU - Rose, K. A.

AU - Curchitser, E. N.

AU - Checkley., Jr M.

AU - Rykaczewski, R. R.

AU - Fiechter, J.

N1 - Publisher Copyright: © 2021 Inter-Research. All rights reserved.

PY - 2021

Y1 - 2021

N2 - Interannual and regime (decadal) scale changes in climate affect the spatial distribution and productivity of marine fish species in numerous ecosystems. We analyzed a historical simulation (1965-2000) from an end-to-end ecosystem model of anchovy population dynamics for the California Current System to untangle the effects of warm versus cool conditions on recruitment. A 3-dimensional coupled hydrodynamic-NPZD (nitrogen-phytoplankton-zooplankton-detritus) model (ROMS-NEMURO) provided the physical conditions (circulation, temperature) and 3 zooplankton concentrations as inputs to an anchovy full life cycle individual-based model (IBM). Our analysis was focused on isolating the effects of the well-documented El Nino Southern Oscillation signal and 3 climate regimes on spawning habitat, development, and survival of eggs and yolksac larvae, growth and survival of larvae and juveniles, and ultimately recruitment of anchovy. The major drivers of lowered recruitment success in warm years and in warmer regimes were reduced survival and growth rates of eggs and larvae that resulted from the poleward shift of adults in response to warmer temperatures prior to spawning. Three model-data comparisons showed the model deviated from empirically derived values of annual recruitment success but agreed with data for annual mean latitude of egg distributions and predicted larval consumption rates versus measured zooplankton concentrations. More effort is needed to improve certain biological aspects of the IBM so that it can replicate empirically estimated recruitment fluctuations. Overall, the altered responses of anchovy to changing climate in the California Current domain illustrate the benefit of the present mechanistic approach to infer how anchovy may respond under future ecosystem conditions.

AB - Interannual and regime (decadal) scale changes in climate affect the spatial distribution and productivity of marine fish species in numerous ecosystems. We analyzed a historical simulation (1965-2000) from an end-to-end ecosystem model of anchovy population dynamics for the California Current System to untangle the effects of warm versus cool conditions on recruitment. A 3-dimensional coupled hydrodynamic-NPZD (nitrogen-phytoplankton-zooplankton-detritus) model (ROMS-NEMURO) provided the physical conditions (circulation, temperature) and 3 zooplankton concentrations as inputs to an anchovy full life cycle individual-based model (IBM). Our analysis was focused on isolating the effects of the well-documented El Nino Southern Oscillation signal and 3 climate regimes on spawning habitat, development, and survival of eggs and yolksac larvae, growth and survival of larvae and juveniles, and ultimately recruitment of anchovy. The major drivers of lowered recruitment success in warm years and in warmer regimes were reduced survival and growth rates of eggs and larvae that resulted from the poleward shift of adults in response to warmer temperatures prior to spawning. Three model-data comparisons showed the model deviated from empirically derived values of annual recruitment success but agreed with data for annual mean latitude of egg distributions and predicted larval consumption rates versus measured zooplankton concentrations. More effort is needed to improve certain biological aspects of the IBM so that it can replicate empirically estimated recruitment fluctuations. Overall, the altered responses of anchovy to changing climate in the California Current domain illustrate the benefit of the present mechanistic approach to infer how anchovy may respond under future ecosystem conditions.

KW - California Current

KW - Climate variation

KW - End-to-end model

KW - Northern anchovy

KW - Recruitment

KW - Regime shift

UR - https://www.scopus.com/pages/publications/85127489601

UR - https://www.scopus.com/pages/publications/85127489601#tab=citedBy

U2 - 10.3354/meps13853

DO - 10.3354/meps13853

M3 - Article

SN - 0171-8630

VL - 680

SP - 111

EP - 136

JO - Marine Ecology Progress Series

JF - Marine Ecology Progress Series

ER -