Abstract
Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007–2009). Snook concentrated in three areas during the spawning season only one of which fell within the expected spawning habitat. Although in lower numbers, they remained in these areas throughout the winter months. Acoustically-tagged snook (n = 31) showed two seasonal patterns at the spawning site: Most fish occurred during the spawning season but several fish displayed more extended residency, supporting the capture-based findings that Common Snook exhibit facultative catadromy. Spawning site selection for iteroparous, multiple-batch spawning fishes occurs at the lifetime, annual, or intra-annual temporal scales. In this study we show colonization of a new spawning site, indicating that lifetime spawning site fidelity of Common Snook is not fixed at this fine spatial scale. However, individuals did exhibit annual and intra-seasonal spawning site fidelity to this new site over the three years studied. The number of fish at the spawning site increased in June and July (peak spawning months) and on new and full lunar phases indicating within population variability in spawning and movement patterns. Intra-seasonal patterns of detection also differed significantly with sex. Common Snook exhibited divergent migration tactics and habitat use at the annual and estuarine scales, with contingents using different overwintering habitat. Migration tactics also varied at the spawning site at the intra-seasonal scale and with sex. These results have important implications for understanding how reproductive behavior affects spatio-temporal patterns of fish abundance and their resilience to disturbance events and fishing pressure.
Highlights
Improving knowledge of stock structure and life cycle processes in diadromous and marine fishes is resulting in new understanding of factors affecting productivity and how to manage for sustainability [1,2,3,4,5,6]
Snook distribution in Tampa Bay More net sets captured snook during the spawning season than in the non-spawning season, but snook were sampled in the estuary year-round
A total of 4,920 seine hauls were conducted by the Fishery-Independent Monitoring (FIM) program in Tampa Bay from 1996 to 2012, and 34% of these caught snook $350 mm standard length (SL)
Summary
Improving knowledge of stock structure and life cycle processes in diadromous and marine fishes is resulting in new understanding of factors affecting productivity and how to manage for sustainability [1,2,3,4,5,6]. Two commonly used conceptual models to address complex stock structure are the metapopulation concept [7,8] and contingent theory [9,10,11], which both focus on spatial distribution of behavioral groups and their ultimate relationship to reproductive isolation. Assessing spatio-temporal patterns in reproductive behavior is becoming more common but results from these studies need to be integrated into concepts of population structure. This is especially important for highly fecund marine species as they typically support important fisheries, exhibit poor stock-recruitment relationships, and their spatio-temporal reproductive behavior may impact productivity as much as, or more than, adult stock size [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
