Last week our own Cormac Booth led two expert elicitation workshops at the National Marine Mammal Foundation in San Diego, as part of the CARMMHA project. CARMMHA stands for the ‘Consortium for Advanced Research on Marine Mammal Health Assessment’, and is a project funded by GoMRI, with a collaborative team from a multitude of institutes including the Office of Protected Resources, University of Illinois, University of St Andrews, National Marine Mammal Foundation, Dauphin Island Sea Lab, University of Connecticut and Sarasota Dolphin Research Program.

The CARMMHA project brings together a team of marine mammal health scientists, with various expertise and specialisms in veterinary assessments, field assessments of wild populations and statistical modelling. These experts are working together to understand how the Deepwater Horizon oil spill may have affected marine mammal health in the Gulf of Mexico.

The statistical models that are intending to explore the potential impacts of the spill on marine mammal population demographics require various parameter estimates, though some of these estimates are currently data poor. As a solution to this, knowledge from a number of experts can be collated and used to inform these parameters. Expert elicitations are a way of getting these probabilistic judgements from experts in a careful, structured process, in order to provide a short-term solution to fill these knowledge gaps and guide future research. Doing this in a structured way minimises biases, such as anchoring, availability bias, confirmation bias and mirroring, and is an improvement on choosing an arbitrary value or asking just one senior expert.

In order to fill key knowledge gaps in population models and cetacean health for a range of Gulf of Mexico cetacean species, and to explore how populations might respond to changes following oil exposure, CARMMHA held two expert elicitation workshops focused on population biology and cetacean health. The questions to experts focused on understanding how exposure to Deepwater Horizon oiling would affect different species and how long it would take for individuals to recover to their health status before oil exposure. Prior to the workshop experts were supplied a compilation of the latest research findings from within the CARMMHA project and the wider field to help supplement their own knowledge and to aid informed judgments.

The workshops were a great success, providing a number of outputs for updating the population models in the CARMMHA project. The outputs of each elicitation question were in the form of probability distributions which provide updated inputs to the population models in CARMMHA. In the future this will result in new population trajectories for each Gulf of Mexico cetacean population considered in the assessment. Keep your eyes on the CARMMHA website for details on the outcomes of these expert elicitations. In the meantime, we want to express a huge thanks to the elicitation team (Lori Schwacke, Len Thomas, Ryan Takeshita, Barb Linnehan and Cormac Booth) and our amazing experts (Philip Dixon, Barb Taylor, Mike Hammill, Alex Zerbini, Tim Gerrodette, Randy Wells, Ailsa Hall, Mike Ziccardi, Nick Kellar, Andreas Fahlman, Tracy Collier, Cynthia Smith).


Expert Elicitation Workshop 1: Population Biology. Attendees (L-R) L to R: Philip Dixon, Ryan Takeshita, Barb Taylor, Mike Hammill, Cormac Booth, Len Thomas, Alex Zerbini, Tim Gerrodette, Lori Schwacke and Randy Wells.


Expert Elicitation Workshop 2: Cetacean Health & Recovery. Attendees L-R: Ailsa Hall, Lori Schwacke, Cormac Booth, Mike Ziccardi, Nick Kellar, Len Thomas, Andreas Fahlman, Tracy Collier, Barb Linnehan and Cynthia Smith.