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

Abstract

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.

Skipped spawning in Northeast Arctic haddock Melanogrammus aeglefinus

“…Although migration distance may be state dependent and adjusted according to individual energy reserves (Jørgensen et al 2008), there is nonetheless a large non-recoverable cost associated with breeding in these fishes. Similar to what has been observed in migratory snook Centropomus undecimalis (Trotter et al 2012) and suggested to be occurring in other migratory species (Jager et al 2008), this may make skipped spawning more prevalent in the longdistance migratory NEA gadoids compared to shortdistance migratory or non-migratory gadoid populations. NEA haddock that skipped also primarily appeared to never start endogenous vitellogenesis, i.e.…”

Reproductive variability of the common snook, Centropomus undecimalis, in environments of contrasting salinities interconnected by the Grijalva–Usumacinta fluvial system

“…La información sobre la migración de varias especies, incluyendo el robalo común en Florida, y la similitud en la frecuencia alélica a nivel genético para los peces de nuestras áreas de estudio, permiten sugerir que los ejemplares de C. undecimalis en la etapa capaz de desovar pueden viajar más de 300 km en el sistema Grijalva-Usumacinta hacia las áreas de desove localizadas en el golfo de México. Sin embargo, Trotter et al (2012) sugieren que en la costa de Florida, hasta el 40% de individuos de C. undecimalis no completa la migración anual para el desove. Estos autores no mencionan la condición gonádica de los peces residentes o no-migrantes, por lo cual no es posible definir la condición gonádica al momento que ocurre.…”

“…Information on migrations of several species, including common snooks in Florida, and similarities in genetic allele frequency for fishes from our study area, allow us to suggest that organisms of C. undecimalis, in spawning capable stage, can travel more than 300 km from the Grijalva-Usumacinta system to the spawning areas located in the Gulf of Mexico. However, Trotter et al (2012) suggested that up to 40% of C. undecimalis individuals do not complete the annual spawning migration that takes place in coastal Florida. These authors do not mention the gonadal condition of the resident or non-migrant fish, so it is not possible to define the condition of gonadal development at the time of this occurrence.…”

More Than Just a Spawning Location: Examining Fine Scale Space Use of Two Estuarine Fish Species at a Spawning Aggregation Site

“…In Florida, the fishery is recreational, and harvest is highly managed with both a slot limit and seasonal closures (Adams, 2016). Snook are marine obligate, highly fecund, batch spawners, that form spawning aggregations at rivermouths, inlets, and possibly on offshore structures (Taylor et al, 1998;Trotter et al, 2012; Boucek unpublished data). The general spawning season for snook is from May to October, with peak spawning occurring in June and July.…”

“…The general spawning season for snook is from May to October, with peak spawning occurring in June and July. During the spawning season, individual Snook generally spend 40-70 days at or near spawning aggregation sites, spawning around dusk on multiple occasions during the spawning season, before migrating back to non-spawning habitats such as freshwater rivers (Trotter et al, 2012;Young et al, 2014). At the focal spawning site during the spawning season, previous research has shown a majority of Snook occupying that area migrate there from inshore overwintering habitats, although a segment of the population are year round residents to the barrier island region (LowerreBarbieri et al, 2014).…”