A Process‐Based Theory of Fishing

ABSTRACT

The processes that lead to the capture of marine organisms in fishing gear are inherently complex, arising from interactions between the deployment of fishing effort, gear efficiency, and species‐specific demography and behaviour. A mechanistic understanding of these processes provides a principled basis for developing management approaches that explicitly account for how different gears interact with different species. Here, we present a general framework for fishing that decomposes capture into the sequential processes of encounter, contact, and retention. We demonstrate how these processes give rise to the emergent properties of catchability and selectivity under varying conditions. Using a set of examples drawn from fish farming, towed gears, and static gears, we show that a common conceptual framework can be applied across diverse fishing contexts, and that the resulting dynamics of catch are consistent with empirical observations. The framework provides a consistent interpretation of fishing effort across gear types and helps to relate existing definitions of fishing processes within a common structure. By synthesising concepts that have traditionally been treated separately in fishing gear technology and stock assessment, this framework provides a flexible basis for incorporating additional biological, technological, and behavioural processes. As such, it offers new insights into how management measures and fishery interactions influence the capture of fish and other marine organisms, with broader implications for fisheries management and ecosystem‐based approaches.