Spatially dynamic maternal control of migratory fish recruitment pulses triggered by shifting seasonal cues

摘要: Environmental regimes set the timing and location of early life-history events migratory species with synchronised reproduction. However, modified habitats in human-dominated landscapes may amplify uncertainty predicting recruitment pulses, impeding efforts to restore invaluable endemic species. The present study assessed how environmental spawner influences modulate variability persistence Missouri River shovelnose sturgeon (Scaphirhynchus platorynchus) under seasonal spawning nursery habitat conditions. Using a spatially explicit individual-based biophysical model, cycle, processes (dispersal, energetics survival) prey production were simulated incrementally perturbed flow (from –10 –30%) temperature (+1 +2°C) over 50 years. Simulated reduction warming synergistically contracted spring (by up 51%) periods 19%). Under these conditions, fewer mature females entered reproductive more skipped spawning, reducing biomass by 20–50%. Many spawners migrated further avoid increasingly unfavourable habitats, intensifying local density dependence larval stages and, turn, increasing size-dependent predation mortality. Diminished egg 20–97%) weakened pulses 46–95%) ultimately reduced population size 21–74%. These simulations illustrate that environmentally amplified maternal on life histories can lower stability resilience ever-increasing perturbations.