Applications of vessel positional data in next-generation stock assessments

Abstract

Stock assessments constitute the foundation of sustainable fisheries management. Stock assessments, traditionally single-stock, non-spatial, and focusing on the biology, abundance and catch components of the fisheries, can be enhanced with additional information from fishery-dependent sources to provide a more accurate picture of stock status and promote positive management outcomes. We conducted a literature review to assess the potential of vessel positional data to help improve or augment stock assessments, expand stock assessments into the spatio-temporal realm, and better integrate human dimensions of fishing into the assessment process. We cataloged the kaleidoscope of variables that can be extracted from vessel positional data to describe fishing activity, and the methods implemented for their calculation. We found that positional data can be used to inform traditional stock assessments by (1) improving indices of fishing effort and stock abundance traditionally calculated using logbook data; (2) mapping the catch component and quantify fishing effort, fishing extent, spatial aggregation, CPUE, catch, landings, bycatch and discards; (3) understanding the individual and collective behavior of fishers, and their change after natural and policy disturbances. The rich information derived from vessel positional data can be used quantitatively to support region-specific stock assessments or as inputs to spatially-explicit stock assessment models. If not used quantitatively, the information can be used during model development and interpretation. These innovative applications involve no additional data-collection cost and utilize straightforward analyses of near-real-time, accurate, fishery-dependent data gathered within the existing management infrastructure.