ssdtools: Open-Source Software for Water Quality Guidelines

Sat, 01 Mar 2025 00:00:00 +0000

Clients: Province of BC, Environment and Climate Change Canada, Australian Government Department of Climate Change, Energy, the Environment and Water

Species sensitivity distributions (SSDs) are the standard statistical method for deriving water quality and environmental guidelines. In 2018, Poisson Consulting released ssdtools, a peer-reviewed R package that fits SSDs using multiple distributions and model averaging, published in the Journal of Open Source Software (Thorley & Schwarz, 2018).

To make the method accessible to non-R users, Poisson Consulting followed up with shinyssdtools (Dalgarno, 2021, Journal of Open Source Software), a Shiny web application that provides a point-and-click interface for the same analyses. In 2025, ssdtools v2 (Thorley, Fisher, Fox & Schwarz, Journal of Open Source Software) added expanded distributions, censored data support, and improved model-averaging methods.

The tools are now used by state regulators in Australia, Canada, and New Zealand. This project demonstrates our commitment to building open, transparent, and reproducible tools that raise the standard for evidence-based environmental protection.

R Packages | Poisson Consulting

ssdtools: Open-Source Software for Water Quality Guidelines