DEBtox information
Making sense of ecotoxicity test results

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DEBtox information

DEBtox information


Welcome to the DEBtox information site

Welcome to the DEBtox information page, the site for people that want to make sense of ecotoxicity data. This site contains information on mechanistic models for the analysis of stressor effects on the life-history traits of individual organisms (and from there to higher and lower levels of biological organisation). Specifically, this site is about models based on animal energy budgets (DEBtox and DEBkiss) and survival models from the GUTS framework.

This website constitutes a node in the international DEBnet network, together with the associated site of DEBtox Research.

The mission of  is to simplify biology to get to the essence of what toxicants (and other stresses) are doing to organisms. Simplification is necessary if we need to gain understanding. Furthermore, we cannot expect to test even a small fraction of all possible (combinations of) toxicants, species and environmental conditions. Once we get to the essence, it is possible to make educated predictions of toxicant effects for untested chemicals, untested species, and under untested conditions.

Here, you can find information, lists of relevant publications, (links to) free e-books, and freely downloadable Matlab packages to analyse your data. Use the major categories on the top left of the screen to navigate through this site; the corresponding sub-categories will appear right next to it in the sub-menu.

Messages and warnings

The free and open-source software openGUTS v1.1 is now available for download! It is available as a standalone Windows executable or as Matlab package. It supports the use of GUTS for regulatory purposes, but will also prove useful for scientific studies. The dedicated website provides more information. Version 1.1 repairs a calculation error that was spotted in openGUTS, which may affect IT calibrations/predictions for specific types of exposure scenarios. The Matlab version has also been updated to v1.1 to repair this. For more information, see the openGUTS website.

For users of BYOM versions before v. 4.3, see the notes and warnings on the BYOM page (bottom of page).
But, really, you should update to a newer version ... If you are working with BYOM, and would like to be notified immediately in case of errors, new versions, etc., email me and I will include you in a mailing list. I may also use this mailing list for other important developments such as new (versions) of the e-books, and new papers. This saves you the hassle of checking this website every week ;-).

                DEBnet network of experts

The Duck of Vaucanson

Upcoming courses and events

  • 9-10 December 2021. GUTS modelling: from the theory to the practice. On-line course via Zoom. This course likely focuses on the Mosaic platform and Bayesian inference. More information.
  • We planned to provide regular GUTS courses, but these plans are put on ice for the moment. More information.
  • Roman Ashauer and myself gave an on-line short course on openGUTS at the 2020 SETAC SciCon. This course is now available for everyone via Leanpub: Although you don't get the interaction with the instructors, this is still a nice way to educate yourself in quarantine.
  • The next DEB school and symposium is planned for the first half of 2023. More info will become available here.
  • The next TKTD summerschool on dynamic modelling of toxic effects is expected to be mid 2023. More info will become available here.

Job opportunities for modellers

  • ...

Latest news

  • 25 November 2021: small update to beta 7 of BYOM, available for download. The old version 5.2. still remains available as well for a while.
  • 15 November 2021: beta 6 version of BYOM available for download. The old version 5.2. remains available as well for a while, since the old files (and the current packages) will not work anymore with the new BYOM version (in general, only small modifications are needed).
  • 28 August 2021: new e-book launched. Mechanistic modelling essentials is now available from Leanpub. More info.
  • 11 June 2021: our MultiCop paper on growth in the copepod Tigriopus brevicornis has been accepted for publication in J. Sea Res. No complete DEB analysis yet, but highly relevant for DEB-based studies of copepods. Available via the DOI.
  • 4 May 2021: discussion paper on the use of reproduction data in DEB-based models. This is a must read for all TKTD modellers that work with reproduction data! A preprint is available at bioRxiv. Paper has been accepted 7 June for publication in IEAM. Early view at
  • 25 February 2021: new version 1.1 of the openGUTS software. See the openGUTS downloads page.
  • 9 February 2021: Error in the BYOM/engine files calc_epx and calc_ecx when used in conjunction with the slice sampler (in Bayesian analyses). The confidence intervals take min-max of the output rather than percentiles (they will thus be too wide). This will be repaired in the next update of BYOM.
  • 27 January 2021: New paper from Sylvain Bart on mixtures with GUTS in ES&T, see
Older news over here.

The DEBtox information site,, since July 2011