Advantages and insights from a hierarchical Bayesian growth and dynamics model based on salmonid electrofishing removal data
Date
2019
Authors
Laplanche, Christophe
Leunda, Pedro M.
Boithias, Laurie
Ardaiz, Jose
Juanes, Francis
Journal Title
Journal ISSN
Volume Title
Publisher
Ecological Modelling
Abstract
Growth is a fundamental ecological process of stream-dwelling salmonids which is strongly
interrelated to critical life history events (emergence, mortality, sexual maturity, smolting,
spawning). The ability to accurately model growth becomes critical when making
population predictions over large temporal (multi-decadal) and spatial (meso) scales, e.g.,
investigating the e ect of global change. Body length collection by removal sampling is a
widely-used practice for monitoring sh populations over such large scales. Such data can
be e ciently integrated into a Hierarchical Bayesian Model (HBM) and lead to interesting
ndings on sh dynamics. We illustrate this approach by presenting an integrated HBM
of brown trout (Salmo trutta) growth, population dynamics, and removal sampling data
collection processes using large temporal and spatial scales data (20 years; 48 sites placed
along a 100 km latitudinal gradient). Growth and population dynamics are modelled by
ordinary di erential equations with parameters bound together in a hierarchical structure.
The observation process is modelled with a combination of a Poisson error, a binomial
error, and a mixture of Gaussian distributions. Absolute t is measured using posterior
predictive checks, which results indicate that our model ts the data well. Results indicate
that growth rate is positively correlated to catchment area. This result corroborates those
of other studies (laboratory, exploratory) that identi ed factors besides water temperature
that are related to daily ration and have a signi cant e ect on stream-dwelling salmonid
growth at a large scale. Our study also illustrates the value of integrated HBM and electro shing removal sampling data to study in situ sh populations over large scales.
Description
Keywords
growth, population dynamics, Salmo trutta, depletion sampling, Iberian peninsula, Mesoscale
Citation
Laplanche, C., Leunda, P.M., Boithias, L., Ardaiz, J., & Juanes, F. (2019). Advantages and insights from a hierarchical Bayesian growth and dynamics model based on salmonid electrofishing removal data. Ecological Modelling, 392. https://doi.org/10.1111/ecog.04476