mizer blog

mizer is an R package to help you build and run multi-species size-spectrum models of fish communities. This blog is for anything related to mizer: new applications, new features, technical details, plans and ideas. Contributions welcome.

Pre-announcing mizer 3.0

mizer 3.0 brings new biological realism, improved numerics, a richer interactive analysis experience, and a composable extension framework

May 13, 2026
Gustav Delius

Age in mizer

In this blog post, we introduce an extension that allows you to calculate dynamic growth curves and ages at size in mizer. This addition will improve how mizer is calibrated to data and also allows it to be interpreted and compared to age-based models, potentially increasing the utility of mizer in the assessment and advice process.

Apr 2, 2025
Luke Broadbent, Michael A. Spence

Mizer 2.4.0

Celebrating Christmas with a new mizer release that makes building realistic multispecies models even simpler.

Dec 23, 2022
Gustav Delius

Don’t use von Bertalanffy growth parameters

Beware of the difference between age-dependent growth curves and the size-dependent growth curves used by mizer.

Nov 30, 2022
Gustav Delius

Temperature-dependent rates in mizer

Temperature is an important driver of ecosystem change. Now you can include it in mizer.

Jul 11, 2022
Phoebe Woodworth-Jefcoats

Tuning growth curves with a shiny gadget

I present to you a new shiny gadget that makes tuning a model to reproduce the desired growth curves feel like child’s play. And this is only a first glimpse of the future of interactively tuning mizer models.

Sep 7, 2021
Gustav Delius

A 5-step recipe for tuning the model steady state

Getting a steady state for your mizer model that agrees with observations is in principle a hard chicken and egg problem. I present the trick that makes it surprisingly easy, with a 5-step recipe. I’ll save tips on what to do when the recipe fails for later blog posts.

Aug 20, 2021
Gustav Delius

Reproducible research with mizer, GitHub, RPubs and binder

Share your code in 5 easy steps, so that others can easily reproduce your results and build on your work.

Aug 14, 2021
Gustav Delius

Change model parameters without using @

Mizer provides dedicated functions for changing model parameters. Using them protects you from pitfalls arising from manipulations with the @ symbol.

Aug 8, 2021
Gustav Delius

Density-dependence in reproduction

The take-home message is that it is important to set the density dependence in your model appropriately and that with the help of the setBevertonHolt() function you can easily make changes to the density dependence without spoiling other aspects of your calibrated model.

Aug 3, 2021
Gustav Delius
 

Welcome to the mizer blog

mizer is now 9 years old. mizer is becoming more social. Time to start a blog.

Aug 1, 2021
Gustav Delius
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