Introduction to some alternative methods for providing scientific information for management

Fisheries management requires scientific information at most steps of the decision cycle (see Dankel and Edwards, Chapter 1, this volume). The methods for providing this information will vary, and several other methods exist in addition to numerical simulations as demonstrated in previous chapters in this volume. We introduce three categories of such methods for providing information to support management decisions: expert judgment, use of mathematical models not involving simulations, and qualitative approaches. Some of these methods are suitable either as a first step in providing information on which to base advice for fisheries management, to be augmented subsequently by more targeted numerical simulations, or else when numerical simulations are impossible due to lack of knowledge, data, or resources to build appropriate models and carry out extensive simulations, or when the complexity of the systems makes modelling simplifications intractable.