Expert elicitation for CARMMHA

We will use expert elicitation to fill key knowledge gaps in population models for a range of Gulf of Mexico cetacean species.

Policymakers and managers are increasingly concerned about the effects of industries on wildlife populations, and in situations where management or conservation decisions need to be made, expert elicitation (asking experts for their judgments in a careful, structured process) is a viable way to provide a short-term fill of knowledge gaps and guide future research.

Elicitation requires experts to make probabilistic judgments, such as median and quartiles, that are difficult and unfamiliar tasks for most experts.

For many species of marine mammals, we lack data on key parameters, for example how long it might take to recover from exposure to oil. Where we lack empirical data, we conduct structured expert elicitations where experts are asked to make probabilistic judgements on these unknown parameters. Critically, this is done in a structured way to minimise biases (e.g. anchoring, availability bias, confirmation bias and mirroring), offering improvements over choosing an arbitrary value or asking the most senior expert you can think of! Here are some examples of how expert elicitation can be used to assess marine mammal issues:

  • Estimating the effect of different levels of disturbance on individual vital rates on harbour porpoise, harbour and grey seals, bottlenose dolphins and minke whales. 
  • How dolphin species might be affected by changes to the marine environment.
  • Exploring the effects of different noise sources on Pacific Walrus adults, juveniles and calves.

Expert elicitation is not an easy process and we have found that invited experts are often unfamiliar with the process and how to express uncertainty in their parameter estimates. Therefore, as part of a research project sponsored by Office of Naval Research, we created a course for experts to take prior to attending expert elicitation workshops so that they can better understand the process and get exposure to the kinds of judgments they will be required to make, before the workshop itself, and in a relaxed, self-paced way.

We will explore how populations might respond to changes following oil exposure.

In CARMMHA, we will use expert elicitation to fill key knowledge gaps in population models for a range of Gulf of Mexico cetacean species. In particular, we are interested in 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. We will also use expert elicitation to explore how populations might respond to changes following oil exposure. To help experts, we will compile the latest research findings from within the CARMMHA project and the wider field – to help supplement their own knowledge and to aid informed judgments.