Migrations of Common Snook from a Tidal River with Implications for Skipped Spawning

摘要

Common snook Centropomus undecimalis support a recreational fishery that contributes greatly to Florida's economy and have been the subject of many diverse studies in which aspects of their life history, reproductive biology, and fishery dynamics have been defined. The current stock assessment contains assumptions based on historical reproductive schedules measured at the population level during the early 1990s. Recent research, however, suggests our understanding of habitat residency and spawning schedules may be overly generalized. We used acoustic telemetry to study the movements and migrations of common snook from the tidal reaches of the Caloosahatchee River, a major tributary of Charlotte Harbor, for 3 years (2005-2007). During this period, 60% of the tagged snook left the study area during at least one spawning season, presumably to enter higher salinity waters where they spawn. The onset and duration of these annual migrations are similar to those reported in previous reproductive studies of snook, but individual dynamics varied. Unexpectedly, 40% of tagged snook remained within the monitored portion of the river for up to three spawning seasons, providing initial evidence for skipped spawning. These detailed data indicate differential individual contributions to total spawning biomass. If further investigation confirms skipped spawning in common snook and shows similar rates of skipped reproduction throughout the snook population, this information should be incorporated into future stock assessments.