Dr Patrick Lynch1, Dr Malin Pinsky2, Melissa Karp1, Jay Peterson1, Roger Griffis1
1NOAA Fisheries, Silver Spring, United States, 2Rutgers, The State University of New Jersey, New Brunswick, United States
Fishery stock assessments are fundamental to sustainable fisheries management. They provide the scientific basis for determining fish stock health (i.e., stock status) and sustainable levels of fishing. Traditionally, stock assessments follow a unit stock approach, where homogeneous population dynamics are assumed stock-wide, and spatial or temporal variability in population dynamics is largely ignored, or modelled implicitly (e.g., via random annual variability in production). However, spatial distributions of marine species are in constant flux, with observations of cyclic variability around average distributions, as well as unidirectional shifts in response to a variety of factors, including climate and ecosystem change. If these added spatial and temporal complexities cause the unit stock assumption to be violated, then the quality of the scientific advice being provided to fishery managers may be compromised. Several managed fish stocks in the U.S. are exhibiting major changes in their spatial distributions and we describe how their stock assessments accounted for those shifts (if at all). Our conclusions support a broader facilitated discussion on the risks and benefits of various approaches to accounting for species distribution shifts in the fishery stock assessment process.
Patrick Lynch leads the National Stock Assessment Program for NOAA Fisheries. His primary role is to support and advance the scientific enterprise that provides quantitative advice to U.S. fishery managers in support of sustainable fisheries. Patrick’s research has focused on fish ecology and population dynamics, and the effects of climate change on marine organisms.