Small pelagic fish exhibit boom-bust cycles driven by fluctuations in recruitment success linked to environmental forcing. The cumulative impacts of these drivers remain poorly understood and are rarely accurately predicted. Without a mechanistic understanding of environment-recruitment linkages, risks to managing fish stocks may increase as the climate changes and underlying linkages shift or break down. Recruitment, or the culmination of parental fecundity and early life stage growth and survival, is determined by 1) behavioral and physiological responses to oceanographic conditions, 2) maternal condition, 3) forage availability, and/or 4) predation. We developed an approach to identify, test, and project the influence of these drivers on Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax) in the California Current System. First, we identified process-based indicators of recruitment from literature review and expert elicitation. Using these indicators and Dynamic Factor Analysis, we derived recruitment indices for each species from 1990 to 2019 and tested model skill for prediction of future recruitment. Indicators of upwelling regime and timing, zooplankton community composition, advective transport, and parental condition were strongly associated with recruitment in these two stocks. We then projected the recruitment indices through the end of the century under climate change using three regionally downscaled ocean projections. Although our models did not improve predictive skill over a persistence prediction at an annual forecast resolution, our approach supports integrating understanding of multiple recruitment mechanisms into strategic management advice and incorporating detailed early life stage dynamics in models of these stocks for effective estimation of climate impacts.
Wildermuth R.P., Tommasi D., Kaplan I.C., Bograd S.J., Hinchliffe C., Hunsicker M.E., Jacox M.G., Koenigstein S., Kuriyama P., Muhling B., Pozo Buil M. and Thompson A. (2026) Revealing climate impacts on recruitment drivers of small pelagic fish through Dynamic Factor Analysis. Marine Ecology Progress Series 787: meps15152. 10.3354/meps15152
@article{Wildermuth2026,
Title = {Revealing climate impacts on recruitment drivers of small pelagic fish through Dynamic Factor Analysis},
Author = {Wildermuth, Robert P. and Tommasi, Désirée and Kaplan, Isaac C. and Bograd, Steven J. and Hinchliffe, Charlie and Hunsicker, Mary E. and Jacox, Michael G. and Koenigstein, Stefan and Kuriyama, Peter and Muhling, Barbara and Pozo Buil, Mercedes and Thompson, Andrew},
Journal = {Marine Ecology Progress Series},
Year = {2026},
Pages = {meps15152},
Volume = {787},
Doi = {10.3354/meps15152},
Abstract = {Small pelagic fish exhibit boom-bust cycles driven by fluctuations in recruitment success linked to environmental forcing. The cumulative impacts of these drivers remain poorly understood and are rarely accurately predicted. Without a mechanistic understanding of environment-recruitment linkages, risks to managing fish stocks may increase as the climate changes and underlying linkages shift or break down. Recruitment, or the culmination of parental fecundity and early life stage growth and survival, is determined by 1) behavioral and physiological responses to oceanographic conditions, 2) maternal condition, 3) forage availability, and/or 4) predation. We developed an approach to identify, test, and project the influence of these drivers on Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax) in the California Current System. First, we identified process-based indicators of recruitment from literature review and expert elicitation. Using these indicators and Dynamic Factor Analysis, we derived recruitment indices for each species from 1990 to 2019 and tested model skill for prediction of future recruitment. Indicators of upwelling regime and timing, zooplankton community composition, advective transport, and parental condition were strongly associated with recruitment in these two stocks. We then projected the recruitment indices through the end of the century under climate change using three regionally downscaled ocean projections. Although our models did not improve predictive skill over a persistence prediction at an annual forecast resolution, our approach supports integrating understanding of multiple recruitment mechanisms into strategic management advice and incorporating detailed early life stage dynamics in models of these stocks for effective estimation of climate impacts.},
}
TY - JOUR
AU - Wildermuth, Robert P.
AU - Tommasi, Désirée
AU - Kaplan, Isaac C.
AU - Bograd, Steven J.
AU - Hinchliffe, Charlie
AU - Hunsicker, Mary E.
AU - Jacox, Michael G.
AU - Koenigstein, Stefan
AU - Kuriyama, Peter
AU - Muhling, Barbara
AU - Pozo Buil, Mercedes
AU - Thompson, Andrew
TI - Revealing climate impacts on recruitment drivers of small pelagic fish through Dynamic Factor Analysis
T2 - Marine Ecology Progress Series
PY - 2026
SP - meps15152
VL - 787
DO - 10.3354/meps15152
AB - Small pelagic fish exhibit boom-bust cycles driven by fluctuations in recruitment success linked to environmental forcing. The cumulative impacts of these drivers remain poorly understood and are rarely accurately predicted. Without a mechanistic understanding of environment-recruitment linkages, risks to managing fish stocks may increase as the climate changes and underlying linkages shift or break down. Recruitment, or the culmination of parental fecundity and early life stage growth and survival, is determined by 1) behavioral and physiological responses to oceanographic conditions, 2) maternal condition, 3) forage availability, and/or 4) predation. We developed an approach to identify, test, and project the influence of these drivers on Pacific sardine (Sardinops sagax) and northern anchovy (Engraulis mordax) in the California Current System. First, we identified process-based indicators of recruitment from literature review and expert elicitation. Using these indicators and Dynamic Factor Analysis, we derived recruitment indices for each species from 1990 to 2019 and tested model skill for prediction of future recruitment. Indicators of upwelling regime and timing, zooplankton community composition, advective transport, and parental condition were strongly associated with recruitment in these two stocks. We then projected the recruitment indices through the end of the century under climate change using three regionally downscaled ocean projections. Although our models did not improve predictive skill over a persistence prediction at an annual forecast resolution, our approach supports integrating understanding of multiple recruitment mechanisms into strategic management advice and incorporating detailed early life stage dynamics in models of these stocks for effective estimation of climate impacts.
ER -
