Scientific Basis for Fisheries Policy and Management

The science foundations of fisheries policy and management have a history of over a century. By the 1920s there was already concern about fisheries that had failed at least on local and sometimes larger scales, and a desire to avoid such failures. From the outset the science foundations were strongly empirical and at best weakly theoretical. This emphasis on empirical approaches was not because fisheries science was necessarily anti-theoretical. Rather, potentially relevant theoretical areas, such as ecology and oceanography, were themselves in their infancy. Established theoretical principles were few, and their relevance to applied problems was largely unexplored. Nevertheless some of the applied problems of unsustainable practices in fisheries were already urgent, and the scientists of the day were seeking ways to use available information to address practical problems. To illustrate, the early work that eventually led to concepts such as maximum sustainable yield (msy) came from empirical observations that as unexploited fish populations were reduced in abundance by a fishery, in many cases somatic growth rates increased, and recruitment to the fisheries at least did not decrease, and in some cases, such as many Pacific salmon, actually increased. These empirical observations began to be systematized into concepts like optimal yield and surplus production by the 1930s. Scientists of the day did explore theoretical concepts like the Verhulst equation in applied contexts, but as efforts to find increasingly powerful mathematical expressions to capture patterns emerging from the empirical data available on how fish populations changed with exploitation. From the beginning, progress was captured in mathematical equations to represent patterns in the information available, facilitating the ability to apply case-specific advances in knowledge to much wider ranges of similar problems. This did not mean the advances in fisheries science were incompatible with evolving fields of ecological, oceanographic, and economic theory. As concepts like carrying capacity and density dependence were elaborated in ecological theory, they enhanced the ability to explain why the empirically-based tools