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Fishery Bulletin 96(2), 1998 
tom type) relationships were difficult to assess. How- 
ever, because pinfish abundance was associated with 
vegetation (seagrasses) in this and other studies 
(Stoner, 1980; Stoner, 1983), the significance of the 
main effects can be proposed in relation to seagrass 
distribution. Higher YOY pinfish abundances may 
have occurred in zones located near bay mouths be- 
cause the largest areas of seagrass are located within 
these zones (Sargent et al., 1995). The absence of 
large expanses of seagrasses in Choctawhatchee Bay 
(Sargent et al, 1995) may have caused YOY pinfish 
to populate shallow-water beach areas abundantly 
to avoid predation (Ruiz et al., 1993). Because mud is 
commonly associated with seagrass beds in shallow- 
water areas of Charlotte Harbor (Mitchell 2 ), higher 
abundances of YOY over mud may be expected. 
It was surprising that more YOY pinfish were cap- 
tured in Choctawhatchee Bay because there is less 
seagrass in this bay than in Tampa Bay or Charlotte 
Harbor (Sargent et al., 1995). Higher abundances of 
YOY pinfish may occur in Choctawhatchee Bay be- 
cause Halodule wrightii, a thin-blade seagrass pre- 
ferred by YOY pinfish for refuge and amphipod for- 
aging ( Stoner, 1982; 1983), occurred more frequently 
( 62%) at vegetated sites in Choctawhatchee Bay than 
at vegetated sites in Tampa Bay (46%) and in Char- 
lotte Harbor (40%). 3 The patchily distributed sea- 
grass beds in Choctawhatchee Bay may also support 
higher abundances of pinfish than the continuously 
distributed seagrass beds in Tampa Bay and Char- 
lotte Harbor because the ecotone between seagrasses 
and unvegetated areas may provide greater habitat 
complexity, offering protection from predators while 
providing close access to alternative feeding areas 
(Holt et al., 1983). 
Factors influencing YOY annual abundance 
Although this study is an exploratory analysis, the 
positive correlation between YOY abundance and sea- 
surface temperatures in Charlotte Harbor suggests 
that oceanographic or biological events that occur 
before settlement may be important factors contrib- 
uting to the annual variability in pinfish abundance. 
Higher temperatures may favor increased hatching 
success (Postuma, 1971) or increased growth of lar- 
vae, or both (Hunter, 1981; Miller et al., 1985; Pepin, 
1991), or they may affect transport mechanisms 
(Lasker, 1984; Rothschild, 1986). For pinfish, both 
2 Mitchell, M. E. 1997. Florida Marine Research Institute, 
Charlotte Harbor Field Laboratory, 1481-A Market Circle, Port 
Charlotte, FL 33953. Personal commun. 
3 Percent occurrence for seagrasses was estimated from random 
sampling data in spring. 
explanations are plausible given that adults spawn 
in offshore Gulf waters. 
Direct spawning stock-recruitment relationships 
are often masked by variability in recruitment 
(Fogarty et al., 1991). The lack of correlation between 
YOY and adult abundances in Charlotte Harbor sug- 
gests that temperature may be a more influential 
factor for this bay. The significant correlation be- 
tween YOY and adult indices at such a low sample 
size does suggest that for Tampa Bay, the relation- 
ship may not be markedly masked, and identifica- 
tion of the actual spawning stock-recruitment pat- 
terns may be possible with additional years of data. 
Growth 
To compare growth rates for YOY pinfish from this 
study with those found for pinfish from Cedar Key, 
FL, Redfish Bay, TX, and the Laguna Madre, TX, I 
fitted the same growth equation to mean length data 
of YOY pinfish estimated from graphical plots shown 
in Caldwell (1957) for Cedar Key, Cameron (1969) 
for Redfish Bay, and Hellier ( 1962) for Laguna Madre, 
for April-July. Instantaneous growth rates were 0.10/ 
month for YOY pinfish from Redfish Bay, TX, 0.17/ 
month from the Laguna Madre, TX, and 0.25/month 
from Cedar Key, FL, indicating that growth in these 
bays was similar to growth of YOY pinfish in the 
three bays studied (Table 4). Similar growth rates 
were expected given that temperatures experienced 
by YOY pinfish among the Gulf coast estuaries were 
alike during the April to July growth period 
(Caldwell, 1957; Cameron, 1969; Hellier, 1962). 
Mortality 
Daily mortality of YOY pinfish in shallow- water ar- 
eas of the three Florida estuaries was low. My esti- 
mates of mortality (0.021-0.023) were similar to 
those made for other estuarine-dependent species 
such as juvenile gulf menhaden ( Brevoortia patronus ) 
in Fourleague Bay, Louisiana (0. 017-0. 021)(Deegan, 
1990), spot (Leiostomus xanthurus) in York River, 
Virginia (0.017) (Weinstein, 1983), and Atlantic 
croaker (Micropogonias undulatus ) in Rose Bay, 
North Carolina (0.023) (Currin et al., 1984). Unfor- 
tunately, I could not estimate mortality of YOY pin- 
fish in deep water because emigration and immigra- 
tion appeared to occur continuously over the spring- 
summer period at fixed trawl stations. 
In summary, YOY pinfish first appeared in shal- 
low-water areas during November in Choctawhatchee 
Bay and during December in Tampa Bay and Char- 
lotte Harbor. In Choctawhatchee Bay and Tampa Bay, 
they were captured in deep water within one month 
