Reproductive Biology and Population Models in Fisheries: Are We Assuming Too Much?

Complex reproductive life history strategies such as hermaphroditism, batch and skip spawning, and variable age at maturity are not always incorporated into management frameworks. Some basic biological data are rarely updated despite strong evidence of fishing- and climate-induced shifts in maturation, spawning frequency, and natural mortality. We often make assumptions about productivity based on theoretical models that assume stationarity and stability in fisheries indicators, and we rely on age structure monitoring to derive recruitment variability. This may lead to over-estimates of steepness and other key demographic parameters that can shift over time. Directional change in climate may invalidate predictions based on historical data. How we collect biological data are equally important –a species’ distribution by depth and/or latitude may substantially confound conclusions, as would gear selectivity. This symposium will explore how much and what type of information may be needed to appropriately incorporate this biological complexity into our population models, and what are the potential consequences of failing to do so.