A statistical framework for identifying the relative importance of ecosystem processes and demographic factors on fish recruitment, with application to Atlantic Herring (Clupea harengus) in the southern Gulf of St. Lawrence

Despite the importance of recruitment for population dynamics and assessing stock status, limited information exists on the relative influence of various ecosystem and demographic factors on the recruitment dynamics of marine fishes. We develop a statistical framework to identify the ecosystem and demographic factors influencing the recruitment and of marine fishes and facilitate improved predictions of recruitment. We demonstrate the approach by examining the relative influence of ecosystem and demographic factors on the recruitment of southern Gulf of St. Lawrence spring and fall spawning Atlantic Herring (Clupea harengus) stocks, highlighting the benefit of considering multiple factors to better understand recruitment trends. We found different combinations of biological and physical ecosystem factors along with demographic had a significant influence on the recruitment and recruitment rate of spring and fall spawning herring. The study emphasizes the value of considering ecosystem characteristics when examining recruitment, provides a framework for researchers to investigate and model recruitment of other fish populations, and supports the continued development and implementation of ecosystem based fisheries management approaches for species such as Atlantic Herring.