We dedicate this paper to the memory of Jonathan Daily, our colleague and friend, who died on 1 March, 2012.
Evaluating a multispecies adaptive management framework: must uncertainty impede effective decision-making?
Article first published online: 27 AUG 2013
Published 2013. This article is a US Government work and is in the public domain in the USA.
Journal of Applied Ecology
Volume 50, Issue 6, pages 1431–1440, December 2013
How to Cite
Smith, D. R., McGowan, C. P., Daily, J. P., Nichols, J. D., Sweka, J. A., Lyons, J. E. (2013), Evaluating a multispecies adaptive management framework: must uncertainty impede effective decision-making?. Journal of Applied Ecology, 50: 1431–1440. doi: 10.1111/1365-2664.12145
- Issue published online: 15 NOV 2013
- Article first published online: 27 AUG 2013
- Manuscript Accepted: 27 JUN 2013
- Manuscript Received: 17 APR 2013
- National Fish and Wildlife Foundation
- US Geological Survey
- US Fish and Wildlife Service
- Atlantic States Marine Fisheries Commission
- adaptive resource management;
- Calidris canutus rufa ;
- expected value of information;
- horseshoe crab;
- Limulus polyphemus ;
- management strategy evaluation;
- multispecies management;
- red knot;
- stochastic dynamic programming
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 Limulus polyphemus, while maintaining adequate stopover habitat for migrating red knots Calidris 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 performance and value of learning. Although natural resource decisions are characterized by uncertainty, not all uncertainty will cause decisions to be altered substantially, as we found in this case. It is important to incorporate uncertainty into the decision framing and evaluate the effect of reducing that uncertainty on achieving the desired outcomes.