An unusually persistent red tide event caused by the ichthyotoxic dinoflagellate Karenia brevis occurred along the southwest Florida coast in 2005. Extensive fish kills led to concerns regarding the effect of red tide on fish populations and their subsequent recruitment. Community structure differences were analyzed for all small-and largebodied nekton species collected by fisheries-independent monitoring from 1996 through 2006. Indices of abundance of five economically important fish species were also calculated from this time period. A significant change in small-and large-bodied nekton community structure was apparent from summer 2005 through spring 2006. Declines in the annual recruitment of juvenile spotted seatrout (Cynoscion nebulosus), sand seatrout (Cynoscion arenarius), and red drum (Sciaenops ocellatus) were evident in 2005 and 2006. Species-specific subadult and adult abundances, however, were consistent with those of previous years. These community shifts and speciesspecific declines appear to be associated with the red tide event.

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Blue crabs (Callinectes sapidus (Rathbun)) are commercially important and are an integral part of the estuarine ecosystem as both predators and prey. Although adult blue crabs have been the focus of many studies, there is little published information on immature blue crab abundances, especially on the west Florida coast. The objectives of this study were to analyze the distributions and abundances of immature and adult blue crabs in the Tampa Bay estuary, specifically as they relate to 1) monthly and yearly trends in abundance and size, 2) timing of recruitment to the estuary, 3) sex-and sizedetermined distribution patterns, and 4) the influence of environmental factors, such as freshwater input. Catch rates, length frequencies, and indices of abundance were calculated for recruiting [#20-mm carapace widths (CW)], juvenile (21-80-mm CW), and adult (.80-mm CW) blue crabs caught during 1996 and 1997. Abundances of all size classes of blue crabs differed by region and month; juvenile and adult abundances were also significantly related to salinity. Immature crabs were collected in all months, confirming an extended spawning season, but there were elevated catches of recruiting blue crabs in February and September. Adults were caught year-round, with males generally being more abundant than females. Geographical regions close to the mouth of the bay had the highest densities of recruits, perhaps because of the supply of larvae being delivered to that area from offshore. With the use of monthly seine and river trawl data from an extended time period (1996-2004), annual variations in the abundance of immature and adult blue crabs were examined. A decline in the abundance of immature crabs collected in 21.3-m seines began after 1998, with a significant low occurring in 2002. A similar pattern was observed for adults collected in river trawls and by commercial fisheries. Unfavorable salinity regimes during this time period may have contributed to these abundance trends.

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