Spatiotemporal variation in flow-dependent recruitment of long-lived riverine fish: Model development and evaluation
Authored by Valery E Forbes, Daisuke Coto, Martin J Hamel, Jeremy J Hammen, Matthew L Rugg, Mark A Pegg
Date Published: 2015
DOI: 10.1016/j.ecolmodel.2014.10.026
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Model Documentation:
ODD
Mathematical description
Model Code URLs:
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Abstract
Natural flow regimes can play a major role as an overarching ecosystem
driver in reproduction and recruitment of riverine fishes. Human needs
for freshwater however have altered hydrology of many riverine systems
worldwide, threatening fish population sustainability. To understand and
predict how spatiotemporal dynamics of flow regimes influence
reproductive and recruitment variability, and ultimately population
sustainability of shovelnose sturgeon (Scaphirhynchus platorynchus), we
develop a spatially explicit (1D) individual-based population model that
mechanistically (via energetics-based processes) simulates daily
activities (dispersal, spawning, foraging, growth, and survival). With
field observations of sturgeon and habitat conditions in a major
tributary of the Missouri River system (USA), we calibrate and evaluate
the model via pattern-oriented modeling. Model simulation experiments
using 17-year environmental time series data showed that seasonal and
interannual variation in hydrological conditions plays a major role in
timing, location, and magnitude of spawning and recruitment success of
sturgeon. During droughts, consecutive weak year-classes resulted in a
steady population decline. While low flow and subsequent low prey
production limited foraging opportunities and slowed gonad development, these conditions were not severe enough for adults to abort the
reproductive cycle. Post-settlement larval sturgeon were however unable
to feed efficiently to grow out of a size-dependent `predation window', resulting in high mortality. Slow growth and low survival of larval
sturgeon thus likely play a larger role in recruitment failures during
droughts than low or lack of spawning events. (C) 2014 Elsevier B.V. All
rights reserved.
Tags
Individual-based model
Atlantic salmon
Climate-change
Life-history characteristics
Lower missouri
river
Shovelnose sturgeon
Scaphirhynchus sturgeon
Mississippi river
Pallid sturgeon
Abiotic
factors