Abundance, Spatial Distribution, and Mortality of Young-of-the-Year Spotted Seatrout (Cynoscion nebulosus) Along the Gulf Coast of Florida

Abstract

We used fixed-station and random-station sampling data from the period 1989-97 to examine spatial and temporal patterns in the abundance and size structure of young-of-the-year (YOY) spotted seatrout, Cynoscion nebulosus, in three Florida estuaries. YOY seatrout first appeared at shallow-water (<1.5 m) seine sites in May-June in Choctawhatchee Bay (Florida Panhandle) and in April-May in Tampa Bay and Charlotte Harbor (both along the southwest Florida peninsula). Spotted seatrout were caught at deepwater (> 1.6 m) trawl stations within 1-3 mo of their initial appearance at shallow-water sites. Most spotted seatrout were caught in waters <3.7 m. Spring and summer peal's in YOY abundance, corresponding to strong influxes of newly spawned individuals, were observed only in southwest peninsula estuaries. Depending on the estuary, the occurrence of YOY spotted seatrout at shallow-water sites was associated with some combination of seagrasses, mangroves, salinity, depth, temperature, and mud. Estimates of total instantaneous mortality rates for YOY spotted seatrout in Tampa Bay were 0.027·d-1 for fixed sites and to 0.025·d-1 for randomly selected sites.