Multidecadal Evidence of Recovery of Nearshore Red Drum Stocks off West-Central Florida and Connectivity with Inshore Nurseries

Abstract

The importance of defining and quantifying ontogenetic movements and connectivity between juvenile and adult fish populations, especially for exploited species, has been well documented. Furthermore, the persistence of strong year-classes can be used to track the success of regulations that contribute to the increased survival and escapement of fish into the adult population. Size and age structures of Red Drum Sciaenops ocellatus were documented within the Tampa Bay estuary, in southwest Florida, using haul seines and trammel nets (1989–2008), and in nearshore Gulf of Mexico waters using a commercial purse seine (2005–2008). In the estuary, juvenile Red Drum (<100-mm TL) were collected from low-salinity backwater areas, and peaks in the annual relative abundance were apparent. In the estuary, Red Drum older than age 4 (>800-mm TL) were rare. Red Drum from nearshore gulf waters ranged from 2 to 35 years of age (674–1,074-mm TL), but most were greater than age 4. After back-calculating ages from Red Drum collected in the estuary and in nearshore gulf waters, we found that specific year-classes of Red Drum, driven by strong juvenile recruitment, were disproportionately represented in the adult spawning stock. We evaluated the long-term effectiveness of fishing regulations as a tool for rebuilding local adult Red Drum stocks by comparing data on size and age structures with results from earlier research conducted in the same geographic area. Adult Red Drum in nearshore waters off Tampa Bay were significantly longer, heavier, and older than were individuals collected a decade earlier, suggesting rebuilding of local Red Drum stocks. These observations validate the utility of long-term, multigear monitoring efforts to track populations from the estuary to nearshore coastal waters.

Received June 27, 2013; accepted April 1, 2014

ACKNOWLEDGMENTS

We thank Steve Leonard (Osprey Flight Services), Captain Nick Ibasfalean (Sunshine Boats) and Captain John Banyas (Cortez Bait and Seafood) and crews for their hard work and success in locating and capturing schools of adult Red Drum in nearshore Gulf waters. Thanks to all biologists of the FIM program for their dedication to field sampling and data processing. Special recognition goes to Sean Fisk for his leadership during field sampling and other project duties; several staff members of various FWRI research sections (Stock Enhancement Research Facility; Genetics; Fish and Wildlife Health; and Fish Biology) for assistance in sampling and processing ancillary samples; and Debbie L. Leffler, Robert H. McMichael Jr., and Mike D. Murphy for their support and assistance. We also thank FIM and FWRI editorial staff and reviewers for providing helpful comments and formatting of the manuscript. This project was supported by a Marine Fisheries Initiative (MARFIN) grant (NA05NMF4331078) from the National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service, proceeds from State of Florida saltwater recreational fishing licenses, and funding from the U.S. Department of the Interior, U.S. Fish and Wildlife Service, Federal Aid for Sport Fish Restoration Project F-43. The statements, findings, views, conclusions, and recommendations contained in this document are those of the authors and do not necessarily reflect the views of NOAA, the U.S. Department of Commerce, or the U.S. Department of the Interior and should not be interpreted as representing the opinions or policies of the U.S. Government.