The targets of management rules for marine mammal populations require justification: A reply to Cooke et al. (2012)

The management of anthropogenic impacts on marine mammal populations involves the setting of targets that are built on assumptions and choices. Scientific methods can be used to investigate the implications of management actions, but the choice of overall objectives and priorities lies outside science. A recent paper (. Potential biological removal and other currently used management rules for marine mammal populations: . A comparison in . Marine Policy), summarised the characteristics of the main approaches currently used to set conservation management targets for marine mammal populations in order to provide a basis for discussion of the targets they contain. Cooke et al. (. Management rules for marine mammal populations: . A response to Lonergan in . Marine Policy) responded, giving some important additional information about these management rules. However most of that paper's criticisms were incorrect or misplaced. Specifically, it erroneously treated an example of how PBR could be reworked, to make its abundance explicit, as a proposal to ignore uncertainty in managing populations. This paper addresses Cooke's main criticisms, and suggests that explicit justifications should be an important part of the process of setting targets for the management of marine mammal populations.