Cahill Analytics

Cahill Analytics

Quantitative expertise for the problems that matter most.

Work With Me

What I Do

Independent quantitative science for clients who need findings that are defensible, rigorous, and honest.

Stock Assessment

Age-structured models, state-space models, statistical catch-at-age, stock-reduction analysis, and data-limited methods.

Harvest Policy & Decision Analysis

Harvest control rule design, management strategy evaluation, biological reference points, and tradeoff analysis under uncertainty.

Statistical Modeling

Bayesian hierarchical models, spatial and spatiotemporal modeling frameworks, mixed-effects models, MCMC, TMB/RTMB/Stan. Fully reproducible pipelines.

Independent Review & Audit

Code audits, assessment reviews, and second opinions on quantitative work. Especially useful when existing analyses may have undetected errors or structural problems.

Training & Capacity Building

Workshop design and delivery for agency, tribal, and academic partners. Advanced statistical methods and R programming for applied ecologists & fisheries scientists.

Model Conversion & RTMB Training

Conversion of legacy assessment code from ADMB and TMB to RTMB, with hands-on training so your team owns and understands the resulting workflows.

About

Over 15 years of applied quantitative science in support of agencies, tribal nations, industry, and academia.

My value to clients is simple: I offer senior quantitative expertise dedicated to your problem. I keep my project load small so that I can deeply engage with the work and deliver clear, honest, and effective analysis when the stakes are high and the problems are complex.

I am an independent quantitative scientist with expertise in stock assessment, population dynamics, and ecological and statistical modeling. I provide clear, rigorous, and defensible analysis for fisheries management, harvest policy design, and complex resource management and ecological modeling challenges. My work spans the Great Lakes, British Columbia coast, Arctic Canada, Alberta, and beyond.

Before independent consulting, I was Associate Director and Assistant Professor at the Quantitative Fisheries Center at Michigan State University, a Postdoctoral Researcher at Simon Fraser University, and a consultant and applied scientist working alongside Alberta Environment and Parks, Fisheries and Oceans Canada, and industry partners.

Selected Expertise

Stock Assessment

  • Assessment reviews
  • Statistical catch-at-age models
  • Stock-reduction analysis
  • Biological reference points
  • Harvest control rules

Statistical Methods

  • Bayesian hierarchical models
  • Spatial and spatiotemporal models
  • Mixed-effects & state-space models
  • MCMC & Laplace approximation
  • Simulation testing

Tools

  • R, RTMB, TMB, ADMB
  • Stan, JAGS
  • Quarto, Git, GitHub
  • Parallel & HPC computing
  • Linux/Unix/Bash

Selected Publications

2025
Montealegre-More et al. Using machine learning to inform harvest control rule design in complex fishery settings. Fish and Fisheries 26: 1004–1020.
2025
Faust et al. Indirect estimation of contact selectivity for gill nets using hierarchical models. Canadian Journal of Fisheries and Aquatic Sciences 82: 1–16.
2022
Cahill et al. Unveiling the recovery dynamics of Walleye after the invisible collapse. Canadian Journal of Fisheries and Aquatic Sciences 79(5): 708–723.
2020
Cahill et al. A spatial-temporal approach to modeling somatic growth across inland recreational fisheries landscapes. Canadian Journal of Fisheries and Aquatic Sciences 77: 1822–1835.
2018
Cahill et al. Multiple challenges confront a high-effort inland recreational fishery in decline. Canadian Journal of Fisheries and Aquatic Sciences 75: 1357–1368.

RTMB

Making stock assessment accessible — without sacrificing rigor.

RTMB is a native R implementation of Template Model Builder that makes state-of-the-art statistical estimation available to anyone who can write R — no C++ required. I am one of its earliest and most active practitioners, and I believe wider adoption makes fisheries science and quantitative ecology more transparent, reproducible, and equitable.

Legacy assessment code written in ADMB or TMB is often opaque to the biologists and managers who depend on it. When only one or two people in an organization can read or modify a model, that model can become a liability — especially when staff turn over or errors go undetected. RTMB changes that. Models written in RTMB are readable, auditable, and maintainable by a much broader community of scientists.

I convert legacy assessment models to RTMB and train the people who maintain them. The goal is not just working code — it is code that your team understands, owns, and can critique and defend.

What I Bring

Conversion Experience

  • Lake Whitefish statistical catch-at-age models converted from ADMB to RTMB for Treaty Waters of the Great Lakes
  • Full translation of modeling examples in Spatio-Temporal Models for Ecologists from TMB to RTMB

Training

  • Maximum likelihood estimation with RTMB (2024, 2025)
  • Uncertainty and diagnostics in RTMB (2026)
  • One-on-one mentoring for agency and tribal biologists

Why It Matters

  • Models are readable by anyone fluent in R
  • No C++ or TMB expertise required to audit or modify
  • Easier peer review and independent verification
  • Reduces key-person dependency in agencies

The Book

I translated the book Spatio-Temporal Models for Ecologists (CRC Press, Authors: Dr. James Thorson and Dr. Kasper Kristensen) to RTMB. I led the conversion of all modeling examples from TMB to RTMB, making the material accessible to a new generation of ecologists and fisheries scientists. Public code is available at: github.com/spacetime-ecologist/spacetime-ecologists-RTMB.

Curriculum Vitae

Consulting CV — updated May 2026.

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Get In Touch

The best engagements start with a conversation about what you need.

Let's Talk

I work with government agencies, tribal nations, academic partners, NGOs, and industry on problems that require deep quantitative expertise. A few sentences about the problem and your timeline are usually enough to tell if I'm the right fit — drop me a line.

Email christopherfishcahill@gmail.com
Based In North America · Remote & On-Site
Google Scholar Christopher Cahill

© 2026 Cahill Analytics · Christopher Cahill, Ph.D.