Evaluating a multispecies adaptive management framework: must uncertainty impede effective decision‐making?

• Published in: Journal of Applied Ecology
• Main Authors: Smith, David R., McGowan, Conor P., Daily, Jonathan P., Nichols, James D., Sweka, John A., Lyons, James E.
• Other Authors: Frederiksen, Morten
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2013
• Subjects: Red Knot
• Online Access: http://dx.doi.org/10.1111/1365-2664.12145; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1365-2664.12145; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2664.12145

Summary Application of adaptive management to complex natural resource systems requires careful evaluation to ensure that the process leads to improved decision‐making. As part of that evaluation, adaptive policies can be compared with alternative nonadaptive management scenarios. Also, the value of reducing structural (ecological) uncertainty to achieving management objectives can be quantified. A multispecies adaptive management framework was recently adopted by the Atlantic States Marine Fisheries Commission for sustainable harvest of Delaware Bay horseshoe crabs L imulus polyphemus, while maintaining adequate stopover habitat for migrating red knots C alidris canutus rufa , the focal shorebird species. The predictive model set encompassed the structural uncertainty in the relationships between horseshoe crab spawning, red knot weight gain and red knot vital rates. Stochastic dynamic programming was used to generate a state‐dependent strategy for harvest decisions given that uncertainty. In this paper, we employed a management strategy evaluation approach to evaluate the performance of this adaptive management framework. Active adaptive management was used by including model weights as state variables in the optimization and reducing structural uncertainty by model weight updating. We found that the value of information for reducing structural uncertainty is expected to be low, because the uncertainty does not appear to impede effective management. Harvest policy responded to abundance levels of both species regardless of uncertainty in the specific relationship that generated those abundances. Thus, the expected horseshoe crab harvest and red knot abundance were similar when the population generating model was uncertain or known, and harvest policy was robust to structural uncertainty as specified. Synthesis and applications . The combination of management strategy evaluation with state‐dependent strategies from stochastic dynamic programming was an informative approach to evaluate adaptive management ...