The Fourth Tampa Bay Area Scientific Information Symposium BASIS 4

• Main Author: Treat, S. F.
• Format: Report
• Language: unknown
• Published: Digital Commons @ University of South Florida 2003
• Subjects: Environmental Indicators and Impact Assessment; Environmental Sciences; Physical Sciences and Mathematics; Red drum; Sciaenops ocellatus
• Online Access: https://digitalcommons.usf.edu/basgp_report/131; https://digitalcommons.usf.edu/context/basgp_report/article/1133/viewcontent/BASIS_4_Workshop_Proceedings.pdf

We have observed large fluctuations in Tampa Bay fish populations over the last decade, and these changes may be associated with the environment, management practices, or other factors. Staff of the Florida Fish and Wildlife and Conservation Commission’s Fish and Wildlife Research Institute began developing the Fisheries-Independent Monitoring (FIM) program in 1988 and have monitored fish populations in Tampa Bay continuously since 1989. Various types of sampling gear have been utilized during the history of FIM, but 21.3-m bag seines have been used since the beginning of the program. This small seine is effective at capturing juveniles of many economically valuable species (e.g., red drum, Sciaenops ocellatus, and spotted seatrout, Cynoscion nebulosus) and juveniles through adults of many small resident species (e.g., bay anchovy, Anchoa mitchilli, and various species of killifish, Fundulidae and Cyprinodontidae). We present indices of relative abundance for 12 groups of fishes (10 species and two multi-specific categories) in three coarsely delimited habitat types in the Tampa Bay system based on collections made with the 21.3-m seine. We then compare trends within these 36 comparisons to major environmental (i.e., drought) and regulatory (i.e., net ban) events that have occurred during the last decade. Significant differences among years were found in 75% of the comparisons. Comparisons indicating no significant interannual changes in abundance were more than twice as common along bay shorelines as they were in offshore areas of the bay or in the tidal rivers, despite a major change in bay-shore sampling methodology by the FIM program in 1998. One-third of the 36 comparisons indicated significant changes in abundance before and after 1995 (i.e., pre- and post-net ban), and all but one of these trends indicated declines in abundance after 1995. This finding is perhaps not surprising because the fish included in this study were primarily small and would serve as prey for harvestable-sized fishes which may have ...