A new paper by Heather Welch titled “Decision support tools for dynamic management” in Conservation Biology highlights the role of decision support tools when integrating multiple species distribution models into a management tool. For example, the question being asked is critically important in the tool design. The algebraic formulation for EcoCast, is highly relative and scales geometrically while Marxan can have exponential relationships because of the algorithm used to ensure a certain percentage of habitat is ultimately protected. It is another good example of where there is no one size fits all approach towards tool building for multiple management goals.
Figure 3. Effect of changing management priorities for leatherback turtles and swordfish on EcoCast (top row) and Marxan (bottom row) tool outputs relative to species habitat suitability. Curves show generalized additive models fit to each weighting run.
Abstract: Spatial management is a valuable strategy to advance regional goals for nature conservation, economic development, and human health. One challenge of spatial management is navigating the prioritization of multiple features. This challenge becomes more pronounced in dynamic management scenarios, in which boundaries are flexible in space and time in response to changing biological, environmental, or socioeconomic conditions. To implement dynamic management, decision support tools are needed to guide spatial prioritization as feature distributions shift under changing conditions. Marxan is a widely applied decision support tool designed for static management scenarios but its utility in dynamic management has not been previously evaluated. EcoCast is a new decision support tool explicitly developed for the dynamic management of multiple features, but is lacking some of Marxan’s functionality. In this study, we compared the capacity of these two decision support tools to prioritize four marine species in a dynamic management scenario for fisheries sustainability. We successfully configured Marxan to operate dynamically on a daily time-scale to parallel EcoCast. The relationship between EcoCast solutions and the underlying species distributions was more linear and less noisy, while Marxan solutions had more contrast between waters that were good and poor to fish. Neither decision support tool clearly outperformed the other; the appropriateness of each will depend on management purpose, resource manager preference, and technological capacity of tool developers.
Welch, S. Brodie, M.G. Jacox, S.J Bograd, E.L. Hazen, 2019. Comparing decision support tools for multi-species dynamic management. Conservation Biology. DOI: 10.1111/cobi.13417 PDF